List separator specifiers in router/transport headers_add/remove. Bug 1581

[exim.git] / doc / doc-docbook / spec.xfpt

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index b1984b5cb3e9a5c3ae040b0f0267290ab6343524..b5133a20140e613cda22ca3467add8ba8e4e6ed5 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -41,16 +41,19 @@
 .book
 
 . /////////////////////////////////////////////////////////////////////////////
 .book
 
 . /////////////////////////////////////////////////////////////////////////////

-. These definitions set some parameters and save some typing. Remember that
-. the <bookinfo> element must also be updated for each new edition.
+. These definitions set some parameters and save some typing.
+. Update the Copyright year (only) when changing content.

 . /////////////////////////////////////////////////////////////////////////////
 
 . /////////////////////////////////////////////////////////////////////////////
 

-.set previousversion "4.75"
-.set version "4.77"
+.set previousversion "4.85"
+.include ./local_params

 
 .set ACL "access control lists (ACLs)"
 .set I   "&nbsp;&nbsp;&nbsp;&nbsp;"
 
 
 .set ACL "access control lists (ACLs)"
 .set I   "&nbsp;&nbsp;&nbsp;&nbsp;"
 

+.macro copyyear
+2014
+.endmacro

 
 . /////////////////////////////////////////////////////////////////////////////
 . Additional xfpt markup used by this document, over and above the default
 
 . /////////////////////////////////////////////////////////////////////////////
 . Additional xfpt markup used by this document, over and above the default


@@ -170,15 +173,18 @@
 <bookinfo>
 <title>Specification of the Exim Mail Transfer Agent</title>
 <titleabbrev>The Exim MTA</titleabbrev>
 <bookinfo>
 <title>Specification of the Exim Mail Transfer Agent</title>
 <titleabbrev>The Exim MTA</titleabbrev>

-<date>06 May 2011</date>
+<date>
+.fulldate
+</date>

 <author><firstname>Exim</firstname><surname>Maintainers</surname></author>
 <authorinitials>EM</authorinitials>
 <revhistory><revision>
 <author><firstname>Exim</firstname><surname>Maintainers</surname></author>
 <authorinitials>EM</authorinitials>
 <revhistory><revision>

-  <revnumber>4.77</revnumber>
-  <date>10 Oct 2011</date>
+.versiondatexml

   <authorinitials>EM</authorinitials>
 </revision></revhistory>
   <authorinitials>EM</authorinitials>
 </revision></revhistory>

-<copyright><year>2011</year><holder>University of Cambridge</holder></copyright>
+<copyright><year>
+.copyyear
+           </year><holder>University of Cambridge</holder></copyright>

 </bookinfo>
 .literal off
 
 </bookinfo>
 .literal off
 


@@ -367,7 +373,7 @@ contributors.
 
 .new
 .cindex "documentation"
 
 .new
 .cindex "documentation"

-This edition of the Exim specification applies to version &version; of Exim.
+This edition of the Exim specification applies to version &version() of Exim.

 Substantive changes from the &previousversion; edition are marked in some
 renditions of the document; this paragraph is so marked if the rendition is
 capable of showing a change indicator.
 Substantive changes from the &previousversion; edition are marked in some
 renditions of the document; this paragraph is so marked if the rendition is
 capable of showing a change indicator.


@@ -533,10 +539,25 @@ The &_.bz2_& file is usually a lot smaller than the &_.gz_& file.
 .cindex "distribution" "signing details"
 .cindex "distribution" "public key"
 .cindex "public key for signed distribution"
 .cindex "distribution" "signing details"
 .cindex "distribution" "public key"
 .cindex "public key for signed distribution"

-The distributions are currently signed with Nigel Metheringham's GPG key. The
-corresponding public key is available from a number of keyservers, and there is
-also a copy in the file &_nigel-pubkey.asc_&. The signatures for the tar bundles are
-in:
+The distributions will be PGP signed by an individual key of the Release
+Coordinator.  This key will have a uid containing an email address in the
+&'exim.org'& domain and will have signatures from other people, including
+other Exim maintainers.  We expect that the key will be in the "strong set" of
+PGP keys.  There should be a trust path to that key from Nigel Metheringham's
+PGP key, a version of which can be found in the release directory in the file
+&_nigel-pubkey.asc_&.  All keys used will be available in public keyserver pools,
+such as &'pool.sks-keyservers.net'&.
+
+At time of last update, releases were being made by Phil Pennock and signed with
+key &'0x403043153903637F'&, although that key is expected to be replaced in 2013.
+A trust path from Nigel's key to Phil's can be observed at
+&url(https://www.security.spodhuis.org/exim-trustpath).
+
+Releases have also been authorized to be performed by Todd Lyons who signs with
+key &'0xC4F4F94804D29EBA'&. A direct trust path exists between previous RE Phil
+Pennock and Todd Lyons through a common associate.
+
+The signatures for the tar bundles are in:

 .display
 &_exim-n.nn.tar.gz.asc_&
 &_exim-n.nn.tar.bz2.asc_&
 .display
 &_exim-n.nn.tar.gz.asc_&
 &_exim-n.nn.tar.bz2.asc_&


@@ -722,6 +743,7 @@ the Exim documentation, &"spool"& is always used in the first sense.
 .cindex "incorporated code"
 .cindex "regular expressions" "library"
 .cindex "PCRE"
 .cindex "incorporated code"
 .cindex "regular expressions" "library"
 .cindex "PCRE"

+.cindex "OpenDMARC"

 A number of pieces of external code are included in the Exim distribution.
 
 .ilist
 A number of pieces of external code are included in the Exim distribution.
 
 .ilist


@@ -846,6 +868,14 @@ ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 SOFTWARE.
 .endblockquote
 
 SOFTWARE.
 .endblockquote
 

+.next
+.cindex "opendmarc" "acknowledgment"
+The DMARC implementation uses the OpenDMARC library which is Copyrighted by
+The Trusted Domain Project. Portions of Exim source which use OpenDMARC
+derived code are indicated in the respective source files. The full OpenDMARC
+license is provided in the LICENSE.opendmarc file contained in the distributed
+source code.
+

 .next
 Many people have contributed code fragments, some large, some small, that were
 not covered by any specific licence requirements. It is assumed that the
 .next
 Many people have contributed code fragments, some large, some small, that were
 not covered by any specific licence requirements. It is assumed that the


@@ -1348,6 +1378,7 @@ Setting the &%verify%& option actually sets two options, &%verify_sender%& and
 &%verify_recipient%&, which independently control the use of the router for
 sender and recipient verification. You can set these options directly if
 you want a router to be used for only one type of verification.
 &%verify_recipient%&, which independently control the use of the router for
 sender and recipient verification. You can set these options directly if
 you want a router to be used for only one type of verification.

+Note that cutthrough delivery is classed as a recipient verification for this purpose.

 .next
 If the &%address_test%& option is set false, the router is skipped when Exim is
 run with the &%-bt%& option to test an address routing. This can be helpful
 .next
 If the &%address_test%& option is set false, the router is skipped when Exim is
 run with the &%-bt%& option to test an address routing. This can be helpful


@@ -1357,6 +1388,7 @@ having to simulate the effect of the scanner.
 .next
 Routers can be designated for use only when verifying an address, as
 opposed to routing it for delivery. The &%verify_only%& option controls this.
 .next
 Routers can be designated for use only when verifying an address, as
 opposed to routing it for delivery. The &%verify_only%& option controls this.

+Again, cutthrough delivery counts as a verification.

 .next
 Individual routers can be explicitly skipped when running the routers to
 check an address given in the SMTP EXPN command (see the &%expn%& option).
 .next
 Individual routers can be explicitly skipped when running the routers to
 check an address given in the SMTP EXPN command (see the &%expn%& option).


@@ -1602,7 +1634,7 @@ for only a short time (see &%timeout_frozen_after%& and
 .section "Unpacking" "SECID23"
 Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
 creates a directory with the name of the current release (for example,
 .section "Unpacking" "SECID23"
 Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
 creates a directory with the name of the current release (for example,

-&_exim-&version;_&) into which the following files are placed:
+&_exim-&version()_&) into which the following files are placed:

 
 .table2 140pt
 .irow &_ACKNOWLEDGMENTS_& "contains some acknowledgments"
 
 .table2 140pt
 .irow &_ACKNOWLEDGMENTS_& "contains some acknowledgments"


@@ -1654,10 +1686,13 @@ modern systems include PCRE as a system library, although you may need
 to install the PCRE or PCRE development package for your operating
 system. If your system has a normal PCRE installation the Exim build
 process will need no further configuration. If the library or the
 to install the PCRE or PCRE development package for your operating
 system. If your system has a normal PCRE installation the Exim build
 process will need no further configuration. If the library or the

-headers are in an unusual location you will need to set the PCRE_LIBS
-and INCLUDE directives appropriately. If your operating system has no
+headers are in an unusual location you will need to either set the PCRE_LIBS
+and INCLUDE directives appropriately,
+or set PCRE_CONFIG=yes to use the installed &(pcre-config)& command.
+If your operating system has no

 PCRE support then you will need to obtain and build the current PCRE
 from &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/).
 PCRE support then you will need to obtain and build the current PCRE
 from &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/).

+More information on PCRE is available at &url(http://www.pcre.org/).

 
 .section "DBM libraries" "SECTdb"
 .cindex "DBM libraries" "discussion of"
 
 .section "DBM libraries" "SECTdb"
 .cindex "DBM libraries" "discussion of"


@@ -1868,6 +1903,12 @@ SUPPORT_TLS=yes
 TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
 TLS_INCLUDE=-I/usr/local/openssl/include/
 .endd
 TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
 TLS_INCLUDE=-I/usr/local/openssl/include/
 .endd

+.cindex "pkg-config" "OpenSSL"
+If you have &'pkg-config'& available, then instead you can just use:
+.code
+SUPPORT_TLS=yes
+USE_OPENSSL_PC=openssl
+.endd

 .cindex "USE_GNUTLS"
 If GnuTLS is installed, you should set
 .code
 .cindex "USE_GNUTLS"
 If GnuTLS is installed, you should set
 .code


@@ -1883,6 +1924,14 @@ USE_GNUTLS=yes
 TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
 TLS_INCLUDE=-I/usr/gnu/include
 .endd
 TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
 TLS_INCLUDE=-I/usr/gnu/include
 .endd

+.cindex "pkg-config" "GnuTLS"
+If you have &'pkg-config'& available, then instead you can just use:
+.code
+SUPPORT_TLS=yes
+USE_GNUTLS=yes
+USE_GNUTLS_PC=gnutls
+.endd
+

 You do not need to set TLS_INCLUDE if the relevant directory is already
 specified in INCLUDE. Details of how to configure Exim to make use of TLS are
 given in chapter &<<CHAPTLS>>&.
 You do not need to set TLS_INCLUDE if the relevant directory is already
 specified in INCLUDE. Details of how to configure Exim to make use of TLS are
 given in chapter &<<CHAPTLS>>&.


@@ -1919,7 +1968,7 @@ in your &_/etc/hosts.allow_& file allows connections from the local host, from
 the subnet 192.168.1.0/24, and from all hosts in &'friendly.domain.example'&.
 All other connections are denied. The daemon name used by &'tcpwrappers'&
 can be changed at build time by setting TCP_WRAPPERS_DAEMON_NAME in
 the subnet 192.168.1.0/24, and from all hosts in &'friendly.domain.example'&.
 All other connections are denied. The daemon name used by &'tcpwrappers'&
 can be changed at build time by setting TCP_WRAPPERS_DAEMON_NAME in

-in &_Local/Makefile_&, or by setting tcp_wrappers_daemon_name in the
+&_Local/Makefile_&, or by setting tcp_wrappers_daemon_name in the

 configure file. Consult the &'tcpwrappers'& documentation for
 further details.
 
 configure file. Consult the &'tcpwrappers'& documentation for
 further details.
 


@@ -2110,6 +2159,26 @@ files or libraries are required. When a lookup type is not included in the
 binary, attempts to configure Exim to use it cause run time configuration
 errors.
 
 binary, attempts to configure Exim to use it cause run time configuration
 errors.
 

+.cindex "pkg-config" "lookups"
+.cindex "pkg-config" "authenticators"
+Many systems now use a tool called &'pkg-config'& to encapsulate information
+about how to compile against a library; Exim has some initial support for
+being able to use pkg-config for lookups and authenticators.  For any given
+makefile variable which starts &`LOOKUP_`& or &`AUTH_`&, you can add a new
+variable with the &`_PC`& suffix in the name and assign as the value the
+name of the package to be queried.  The results of querying via the
+&'pkg-config'& command will be added to the appropriate Makefile variables
+with &`+=`& directives, so your version of &'make'& will need to support that
+syntax.  For instance:
+.code
+LOOKUP_SQLITE=yes
+LOOKUP_SQLITE_PC=sqlite3
+AUTH_GSASL=yes
+AUTH_GSASL_PC=libgsasl
+AUTH_HEIMDAL_GSSAPI=yes
+AUTH_HEIMDAL_GSSAPI_PC=heimdal-gssapi
+.endd
+

 .cindex "Perl" "including support for"
 Exim can be linked with an embedded Perl interpreter, allowing Perl
 subroutines to be called during string expansion. To enable this facility,
 .cindex "Perl" "including support for"
 Exim can be linked with an embedded Perl interpreter, allowing Perl
 subroutines to be called during string expansion. To enable this facility,


@@ -2261,7 +2330,7 @@ INFO_DIRECTORY, as described in section &<<SECTinsinfdoc>>& below.
 For the utility programs, old versions are renamed by adding the suffix &_.O_&
 to their names. The Exim binary itself, however, is handled differently. It is
 installed under a name that includes the version number and the compile number,
 For the utility programs, old versions are renamed by adding the suffix &_.O_&
 to their names. The Exim binary itself, however, is handled differently. It is
 installed under a name that includes the version number and the compile number,

-for example &_exim-&version;-1_&. The script then arranges for a symbolic link
+for example &_exim-&version()-1_&. The script then arranges for a symbolic link

 called &_exim_& to point to the binary. If you are updating a previous version
 of Exim, the script takes care to ensure that the name &_exim_& is never absent
 from the directory (as seen by other processes).
 called &_exim_& to point to the binary. If you are updating a previous version
 of Exim, the script takes care to ensure that the name &_exim_& is never absent
 from the directory (as seen by other processes).


@@ -2641,6 +2710,13 @@ no arguments.
 This option is an alias for &%-bV%& and causes version information to be
 displayed.
 
 This option is an alias for &%-bV%& and causes version information to be
 displayed.
 

+.vitem &%-Ac%& &&&
+       &%-Am%&
+.oindex "&%-Ac%&"
+.oindex "&%-Am%&"
+These options are used by Sendmail for selecting configuration files and are
+ignored by Exim.
+

 .vitem &%-B%&<&'type'&>
 .oindex "&%-B%&"
 .cindex "8-bit characters"
 .vitem &%-B%&<&'type'&>
 .oindex "&%-B%&"
 .cindex "8-bit characters"


@@ -2900,11 +2976,37 @@ use the &'exim_dbmbuild'& utility, or some other means, to rebuild alias files
 if this is required. If the &%bi_command%& option is not set, calling Exim with
 &%-bi%& is a no-op.
 
 if this is required. If the &%bi_command%& option is not set, calling Exim with
 &%-bi%& is a no-op.
 

+. // Keep :help first, then the rest in alphabetical order
+.vitem &%-bI:help%&
+.oindex "&%-bI:help%&"
+.cindex "querying exim information"
+We shall provide various options starting &`-bI:`& for querying Exim for
+information.  The output of many of these will be intended for machine
+consumption.  This one is not.  The &%-bI:help%& option asks Exim for a
+synopsis of supported options beginning &`-bI:`&.  Use of any of these
+options shall cause Exim to exit after producing the requested output.
+
+.vitem &%-bI:dscp%&
+.oindex "&%-bI:dscp%&"
+.cindex "DSCP" "values"
+This option causes Exim to emit an alphabetically sorted list of all
+recognised DSCP names.
+
+.vitem &%-bI:sieve%&
+.oindex "&%-bI:sieve%&"
+.cindex "Sieve filter" "capabilities"
+This option causes Exim to emit an alphabetically sorted list of all supported
+Sieve protocol extensions on stdout, one per line.  This is anticipated to be
+useful for ManageSieve (RFC 5804) implementations, in providing that protocol's
+&`SIEVE`& capability response line.  As the precise list may depend upon
+compile-time build options, which this option will adapt to, this is the only
+way to guarantee a correct response.
+

 .vitem &%-bm%&
 .oindex "&%-bm%&"
 .cindex "local message reception"
 This option runs an Exim receiving process that accepts an incoming,
 .vitem &%-bm%&
 .oindex "&%-bm%&"
 .cindex "local message reception"
 This option runs an Exim receiving process that accepts an incoming,

-locally-generated message on the current input. The recipients are given as the
+locally-generated message on the standard input. The recipients are given as the

 command arguments (except when &%-t%& is also present &-- see below). Each
 argument can be a comma-separated list of RFC 2822 addresses. This is the
 default option for selecting the overall action of an Exim call; it is assumed
 command arguments (except when &%-t%& is also present &-- see below). Each
 argument can be a comma-separated list of RFC 2822 addresses. This is the
 default option for selecting the overall action of an Exim call; it is assumed


@@ -2946,6 +3048,26 @@ The specified sender is treated as if it were given as the argument to the
 preference to the address taken from the message. The caller of Exim must be a
 trusted user for the sender of a message to be set in this way.
 
 preference to the address taken from the message. The caller of Exim must be a
 trusted user for the sender of a message to be set in this way.
 

+.vitem &%-bmalware%&&~<&'filename'&>
+.oindex "&%-bmalware%&"
+.cindex "testing", "malware"
+.cindex "malware scan test"
+This debugging option causes Exim to scan the given file,
+using the malware scanning framework.  The option of &%av_scanner%& influences
+this option, so if &%av_scanner%&'s value is dependent upon an expansion then
+the expansion should have defaults which apply to this invocation.  ACLs are
+not invoked, so if &%av_scanner%& references an ACL variable then that variable
+will never be populated and &%-bmalware%& will fail.
+
+Exim will have changed working directory before resolving the filename, so
+using fully qualified pathnames is advisable.  Exim will be running as the Exim
+user when it tries to open the file, rather than as the invoking user.
+This option requires admin privileges.
+
+The &%-bmalware%& option will not be extended to be more generally useful,
+there are better tools for file-scanning.  This option exists to help
+administrators verify their Exim and AV scanner configuration.
+

 .vitem &%-bnq%&
 .oindex "&%-bnq%&"
 .cindex "address qualification, suppressing"
 .vitem &%-bnq%&
 .oindex "&%-bnq%&"
 .cindex "address qualification, suppressing"


@@ -2993,6 +3115,10 @@ configuration file is output.
 If a list of configuration files was supplied, the value that is output here
 is the name of the file that was actually used.
 
 If a list of configuration files was supplied, the value that is output here
 is the name of the file that was actually used.
 

+.cindex "options" "hiding name of"
+If the &%-n%& flag is given, then for most modes of &%-bP%& operation the
+name will not be output.
+

 .cindex "daemon" "process id (pid)"
 .cindex "pid (process id)" "of daemon"
 If &%log_file_path%& or &%pid_file_path%& are given, the names of the
 .cindex "daemon" "process id (pid)"
 .cindex "pid (process id)" "of daemon"
 If &%log_file_path%& or &%pid_file_path%& are given, the names of the


@@ -3206,26 +3332,6 @@ above concerning senders and qualification do not apply. In this situation,
 Exim behaves in exactly the same way as it does when receiving a message via
 the listening daemon.
 
 Exim behaves in exactly the same way as it does when receiving a message via
 the listening daemon.
 

-.vitem &%-bmalware%&&~<&'filename'&>
-.oindex "&%-bmalware%&"
-.cindex "testing", "malware"
-.cindex "malware scan test"
-This debugging option causes Exim to scan the given file,
-using the malware scanning framework.  The option of &%av_scanner%& influences
-this option, so if &%av_scanner%&'s value is dependent upon an expansion then
-the expansion should have defaults which apply to this invocation.  ACLs are
-not invoked, so if &%av_scanner%& references an ACL variable then that variable
-will never be populated and &%-bmalware%& will fail.
-
-Exim will have changed working directory before resolving the filename, so
-using fully qualified pathnames is advisable.  Exim will be running as the Exim
-user when it tries to open the file, rather than as the invoking user.
-This option requires admin privileges.
-
-The &%-bmalware%& option will not be extended to be more generally useful,
-there are better tools for file-scanning.  This option exists to help
-administrators verify their Exim and AV scanner configuration.
-

 .vitem &%-bt%&
 .oindex "&%-bt%&"
 .cindex "testing" "addresses"
 .vitem &%-bt%&
 .oindex "&%-bt%&"
 .cindex "testing" "addresses"


@@ -3346,6 +3452,23 @@ This option acts like &%-bv%&, but verifies the address as a sender rather
 than a recipient address. This affects any rewriting and qualification that
 might happen.
 
 than a recipient address. This affects any rewriting and qualification that
 might happen.
 

+.vitem &%-bw%&
+.oindex "&%-bw%&"
+.cindex "daemon"
+.cindex "inetd"
+.cindex "inetd" "wait mode"
+This option runs Exim as a daemon, awaiting incoming SMTP connections,
+similarly to the &%-bd%& option.  All port specifications on the command-line
+and in the configuration file are ignored.  Queue-running may not be specified.
+
+In this mode, Exim expects to be passed a socket as fd 0 (stdin) which is
+listening for connections.  This permits the system to start up and have
+inetd (or equivalent) listen on the SMTP ports, starting an Exim daemon for
+each port only when the first connection is received.
+
+If the option is given as &%-bw%&<&'time'&> then the time is a timeout, after
+which the daemon will exit, which should cause inetd to listen once more.
+

 .vitem &%-C%&&~<&'filelist'&>
 .oindex "&%-C%&"
 .cindex "configuration file" "alternate"
 .vitem &%-C%&&~<&'filelist'&>
 .oindex "&%-C%&"
 .cindex "configuration file" "alternate"


@@ -3598,8 +3721,17 @@ if &%-f%& is also present, it overrides &"From&~"&.
 
 .vitem &%-G%&
 .oindex "&%-G%&"
 
 .vitem &%-G%&
 .oindex "&%-G%&"

-.cindex "Sendmail compatibility" "&%-G%& option ignored"
-This is a Sendmail option which is ignored by Exim.
+.cindex "submission fixups, suppressing (command-line)"
+This option is equivalent to an ACL applying:
+.code
+control = suppress_local_fixups
+.endd
+for every message received.  Note that Sendmail will complain about such
+bad formatting, where Exim silently just does not fix it up.  This may change
+in future.
+
+As this affects audit information, the caller must be a trusted user to use
+this option.

 
 .vitem &%-h%&&~<&'number'&>
 .oindex "&%-h%&"
 
 .vitem &%-h%&&~<&'number'&>
 .oindex "&%-h%&"


@@ -3617,6 +3749,17 @@ line by itself should not terminate an incoming, non-SMTP message. I can find
 no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
 command in Solaris 2.4 uses it. See also &%-ti%&.
 
 no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
 command in Solaris 2.4 uses it. See also &%-ti%&.
 

+.vitem &%-L%&&~<&'tag'&>
+.oindex "&%-L%&"
+.cindex "syslog" "process name; set with flag"
+This option is equivalent to setting &%syslog_processname%& in the config
+file and setting &%log_file_path%& to &`syslog`&.
+Its use is restricted to administrators.  The configuration file has to be
+read and parsed, to determine access rights, before this is set and takes
+effect, so early configuration file errors will not honour this flag.
+
+The tag should not be longer than 32 characters.
+

 .vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
 .oindex "&%-M%&"
 .cindex "forcing delivery"
 .vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
 .oindex "&%-M%&"
 .cindex "forcing delivery"


@@ -3668,6 +3811,14 @@ This option is not intended for use by external callers. It is used internally
 by Exim in conjunction with the &%-MC%& option. It signifies that the
 connection to the remote host has been authenticated.
 
 by Exim in conjunction with the &%-MC%& option. It signifies that the
 connection to the remote host has been authenticated.
 

+.new
+.vitem &%-MCD%&
+.oindex "&%-MCD%&"
+This option is not intended for use by external callers. It is used internally
+by Exim in conjunction with the &%-MC%& option. It signifies that the
+remote host supports the ESMTP &_DSN_& extension.
+.wen
+

 .vitem &%-MCP%&
 .oindex "&%-MCP%&"
 This option is not intended for use by external callers. It is used internally
 .vitem &%-MCP%&
 .oindex "&%-MCP%&"
 This option is not intended for use by external callers. It is used internally


@@ -3857,9 +4008,9 @@ for that message.
 
 .vitem &%-n%&
 .oindex "&%-n%&"
 
 .vitem &%-n%&
 .oindex "&%-n%&"

-.cindex "Sendmail compatibility" "&%-n%& option ignored"
-This option is interpreted by Sendmail to mean &"no aliasing"&. It is ignored
-by Exim.
+This option is interpreted by Sendmail to mean &"no aliasing"&.
+For normal modes of operation, it is ignored by Exim.
+When combined with &%-bP%& it suppresses the name of an option from being output.

 
 .vitem &%-O%&&~<&'data'&>
 .oindex "&%-O%&"
 
 .vitem &%-O%&&~<&'data'&>
 .oindex "&%-O%&"


@@ -3973,8 +4124,8 @@ message.
 Provided
 this error message is successfully sent, the Exim receiving process
 exits with a return code of zero. If not, the return code is 2 if the problem
 Provided
 this error message is successfully sent, the Exim receiving process
 exits with a return code of zero. If not, the return code is 2 if the problem

-is that the original message has no recipients, or 1 any other error. This is
-the default &%-oe%&&'x'& option if Exim is called as &'rmail'&.
+is that the original message has no recipients, or 1 for any other error.
+This is the default &%-oe%&&'x'& option if Exim is called as &'rmail'&.

 
 .vitem &%-oem%&
 .oindex "&%-oem%&"
 
 .vitem &%-oem%&
 .oindex "&%-oem%&"


@@ -4078,6 +4229,20 @@ option sets the IP interface address value. A port number may be included,
 using the same syntax as for &%-oMa%&. The interface address is placed in
 &$received_ip_address$& and the port number, if present, in &$received_port$&.
 
 using the same syntax as for &%-oMa%&. The interface address is placed in
 &$received_ip_address$& and the port number, if present, in &$received_port$&.
 

+.vitem &%-oMm%&&~<&'message&~reference'&>
+.oindex "&%-oMm%&"
+.cindex "message reference" "message reference, specifying for local message"
+See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMm%&
+option sets the message reference, e.g. message-id, and is logged during
+delivery. This is useful when some kind of audit trail is required to tie
+messages together. The format of the message reference is checked and will
+abort if the format is invalid. The option will only be accepted if exim is
+running in trusted mode, not as any regular user.
+
+The best example of a message reference is when Exim sends a bounce message.
+The message reference is the message-id of the original message for which Exim
+is sending the bounce.
+

 .vitem &%-oMr%&&~<&'protocol&~name'&>
 .oindex "&%-oMr%&"
 .cindex "protocol, specifying for local message"
 .vitem &%-oMr%&&~<&'protocol&~name'&>
 .oindex "&%-oMr%&"
 .cindex "protocol, specifying for local message"


@@ -4187,7 +4352,7 @@ For compatibility with Sendmail, this option is equivalent to
 It sets the incoming protocol and host name (for trusted callers). The
 host name and its colon can be omitted when only the protocol is to be set.
 Note the Exim already has two private options, &%-pd%& and &%-ps%&, that refer
 It sets the incoming protocol and host name (for trusted callers). The
 host name and its colon can be omitted when only the protocol is to be set.
 Note the Exim already has two private options, &%-pd%& and &%-ps%&, that refer

-to embedded Perl. It is therefore impossible to set a protocol value of &`p`&
+to embedded Perl. It is therefore impossible to set a protocol value of &`d`&

 or &`s`& using this option (but that does not seem a real limitation).
 
 .vitem &%-q%&
 or &`s`& using this option (but that does not seem a real limitation).
 
 .vitem &%-q%&


@@ -4394,7 +4559,7 @@ has &'f'& or &'ff'& in its flags, the associated action is taken.
 
 .vitem &%-Tqt%&&~<&'times'&>
 .oindex "&%-Tqt%&"
 
 .vitem &%-Tqt%&&~<&'times'&>
 .oindex "&%-Tqt%&"

-This an option that is exclusively for use by the Exim testing suite. It is not
+This is an option that is exclusively for use by the Exim testing suite. It is not

 recognized when Exim is run normally. It allows for the setting up of explicit
 &"queue times"& so that various warning/retry features can be tested.
 
 recognized when Exim is run normally. It allows for the setting up of explicit
 &"queue times"& so that various warning/retry features can be tested.
 


@@ -4478,6 +4643,18 @@ AIX uses &%-x%& for a private purpose (&"mail from a local mail program has
 National Language Support extended characters in the body of the mail item"&).
 It sets &%-x%& when calling the MTA from its &%mail%& command. Exim ignores
 this option.
 National Language Support extended characters in the body of the mail item"&).
 It sets &%-x%& when calling the MTA from its &%mail%& command. Exim ignores
 this option.

+
+.vitem &%-X%&&~<&'logfile'&>
+.oindex "&%-X%&"
+This option is interpreted by Sendmail to cause debug information to be sent
+to the named file.  It is ignored by Exim.
+
+.vitem &%-z%&&~<&'log-line'&>
+.oindex "&%-z%&"
+This option writes its argument to Exim's logfile.
+Use is restricted to administrators; the intent is for operational notes.
+Quotes should be used to maintain a multi-word item as a single argument,
+under most shells.

 .endlist
 
 .ecindex IIDclo1
 .endlist
 
 .ecindex IIDclo1


@@ -5241,7 +5418,7 @@ it is unset, Exim uses the &[uname()]& system function to obtain the host name.
 
 The first three non-comment configuration lines are as follows:
 .code
 
 The first three non-comment configuration lines are as follows:
 .code

-domainlist local_domains = @
+domainlist local_domains    = @

 domainlist relay_to_domains =
 hostlist   relay_from_hosts = 127.0.0.1
 .endd
 domainlist relay_to_domains =
 hostlist   relay_from_hosts = 127.0.0.1
 .endd


@@ -5396,15 +5573,20 @@ The next two lines are concerned with &'ident'& callbacks, as defined by RFC
 1413 (hence their names):
 .code
 rfc1413_hosts = *
 1413 (hence their names):
 .code
 rfc1413_hosts = *

-rfc1413_query_timeout = 5s
+rfc1413_query_timeout = 0s
+.endd
+These settings cause Exim to avoid ident callbacks for all incoming SMTP calls.
+Few hosts offer RFC1413 service these days; calls have to be
+terminated by a timeout and this needlessly delays the startup
+of an incoming SMTP connection.
+If you have hosts for which you trust RFC1413 and need this
+information, you can change this.
+
+This line enables an efficiency SMTP option.  It is negotiated by clients
+and not expected to cause problems but can be disabled if needed.
+.code
+prdr_enable = true

 .endd
 .endd

-These settings cause Exim to make ident callbacks for all incoming SMTP calls.
-You can limit the hosts to which these calls are made, or change the timeout
-that is used. If you set the timeout to zero, all ident calls are disabled.
-Although they are cheap and can provide useful information for tracing problem
-messages, some hosts and firewalls have problems with ident calls. This can
-result in a timeout instead of an immediate refused connection, leading to
-delays on starting up an incoming SMTP session.

 
 When Exim receives messages over SMTP connections, it expects all addresses to
 be fully qualified with a domain, as required by the SMTP definition. However,
 
 When Exim receives messages over SMTP connections, it expects all addresses to
 be fully qualified with a domain, as required by the SMTP definition. However,


@@ -5583,7 +5765,7 @@ examples described in &<<SECTdefconfauth>>&. This means that no client can in
 fact authenticate until you complete the authenticator definitions.
 .code
 require message = relay not permitted
 fact authenticate until you complete the authenticator definitions.
 .code
 require message = relay not permitted

-        domains = +local_domains : +relay_domains
+        domains = +local_domains : +relay_to_domains

 .endd
 This statement rejects the address if its domain is neither a local domain nor
 one of the domains for which this host is a relay.
 .endd
 This statement rejects the address if its domain is neither a local domain nor
 one of the domains for which this host is a relay.


@@ -5840,9 +6022,14 @@ One remote transport and four local transports are defined.
 .code
 remote_smtp:
   driver = smtp
 .code
 remote_smtp:
   driver = smtp

+  hosts_try_prdr = *

 .endd
 .endd

-This transport is used for delivering messages over SMTP connections. All its
-options are defaulted. The list of remote hosts comes from the router.
+This transport is used for delivering messages over SMTP connections.
+The list of remote hosts comes from the router.
+The &%hosts_try_prdr%& option enables an efficiency SMTP option.
+It is negotiated between client and server
+and not expected to cause problems but can be disabled if needed.
+All other options are defaulted.

 .code
 local_delivery:
   driver = appendfile
 .code
 local_delivery:
   driver = appendfile


@@ -5945,7 +6132,7 @@ The example PLAIN authenticator looks like this:
 #  server_set_id           = $auth2
 #  server_prompts          = :
 #  server_condition        = Authentication is not yet configured
 #  server_set_id           = $auth2
 #  server_prompts          = :
 #  server_condition        = Authentication is not yet configured

-#  server_advertise_condition = ${if def:tls_cipher }
+#  server_advertise_condition = ${if def:tls_in_cipher }

 .endd
 And the example LOGIN authenticator looks like this:
 .code
 .endd
 And the example LOGIN authenticator looks like this:
 .code


@@ -5954,7 +6141,7 @@ And the example LOGIN authenticator looks like this:
 #  server_set_id           = $auth1
 #  server_prompts          = <| Username: | Password:
 #  server_condition        = Authentication is not yet configured
 #  server_set_id           = $auth1
 #  server_prompts          = <| Username: | Password:
 #  server_condition        = Authentication is not yet configured

-#  server_advertise_condition = ${if def:tls_cipher }
+#  server_advertise_condition = ${if def:tls_in_cipher }

 .endd
 
 The &%server_set_id%& option makes Exim remember the authenticated username
 .endd
 
 The &%server_set_id%& option makes Exim remember the authenticated username


@@ -5964,16 +6151,16 @@ that it implements the details of the specific authentication mechanism,
 i.e. PLAIN or LOGIN. The &%server_advertise_condition%& setting controls
 when Exim offers authentication to clients; in the examples, this is only
 when TLS or SSL has been started, so to enable the authenticators you also
 i.e. PLAIN or LOGIN. The &%server_advertise_condition%& setting controls
 when Exim offers authentication to clients; in the examples, this is only
 when TLS or SSL has been started, so to enable the authenticators you also

-need to add support for TLS as described in &<<SECTdefconfmain>>&.
+need to add support for TLS as described in section &<<SECTdefconfmain>>&.

 
 The &%server_condition%& setting defines how to verify that the username and
 password are correct. In the examples it just produces an error message.
 To make the authenticators work, you can use a string expansion
 
 The &%server_condition%& setting defines how to verify that the username and
 password are correct. In the examples it just produces an error message.
 To make the authenticators work, you can use a string expansion

-expression like one of the examples in &<<CHAPplaintext>>&.
+expression like one of the examples in chapter &<<CHAPplaintext>>&.

 
 Beware that the sequence of the parameters to PLAIN and LOGIN differ; the
 
 Beware that the sequence of the parameters to PLAIN and LOGIN differ; the

-usercode and password are in different positions.  &<<CHAPplaintext>>&
-covers both.
+usercode and password are in different positions.
+Chapter &<<CHAPplaintext>>& covers both.

 
 .ecindex IIDconfiwal
 
 
 .ecindex IIDconfiwal
 


@@ -6184,12 +6371,23 @@ the DB_UNKNOWN option. This enables it to handle any of the types of database
 that the library supports, and can be useful for accessing DBM files created by
 other applications. (For earlier DB versions, DB_HASH is always used.)
 .next
 that the library supports, and can be useful for accessing DBM files created by
 other applications. (For earlier DB versions, DB_HASH is always used.)
 .next

+.cindex "lookup" "dbmjz"
+.cindex "lookup" "dbm &-- embedded NULs"
+.cindex "sasldb2"
+.cindex "dbmjz lookup type"
+&(dbmjz)&: This is the same as &(dbm)&, except that the lookup key is
+interpreted as an Exim list; the elements of the list are joined together with
+ASCII NUL characters to form the lookup key.  An example usage would be to
+authenticate incoming SMTP calls using the passwords from Cyrus SASL's
+&_/etc/sasldb2_& file with the &(gsasl)& authenticator or Exim's own
+&(cram_md5)& authenticator.
+.next

 .cindex "lookup" "dbmnz"
 .cindex "lookup" "dbm &-- terminating zero"
 .cindex "binary zero" "in lookup key"
 .cindex "Courier"
 .cindex "&_/etc/userdbshadow.dat_&"
 .cindex "lookup" "dbmnz"
 .cindex "lookup" "dbm &-- terminating zero"
 .cindex "binary zero" "in lookup key"
 .cindex "Courier"
 .cindex "&_/etc/userdbshadow.dat_&"

-.cindex "dmbnz lookup type"
+.cindex "dbmnz lookup type"

 &(dbmnz)&: This is the same as &(dbm)&, except that a terminating binary zero
 is not included in the key that is passed to the DBM library. You may need this
 if you want to look up data in files that are created by or shared with some
 &(dbmnz)&: This is the same as &(dbm)&, except that a terminating binary zero
 is not included in the key that is passed to the DBM library. You may need this
 if you want to look up data in files that are created by or shared with some


@@ -6681,8 +6879,8 @@ is used on its own as the result. If the lookup does not succeed, the
 &`fail`& keyword causes a &'forced expansion failure'& &-- see section
 &<<SECTforexpfai>>& for an explanation of what this means.
 
 &`fail`& keyword causes a &'forced expansion failure'& &-- see section
 &<<SECTforexpfai>>& for an explanation of what this means.
 

-The supported DNS record types are A, CNAME, MX, NS, PTR, SRV, and TXT, and,
-when Exim is compiled with IPv6 support, AAAA (and A6 if that is also
+The supported DNS record types are A, CNAME, MX, NS, PTR, SPF, SRV, TLSA and TXT,
+and, when Exim is compiled with IPv6 support, AAAA (and A6 if that is also

 configured). If no type is given, TXT is assumed. When the type is PTR,
 the data can be an IP address, written as normal; inversion and the addition of
 &%in-addr.arpa%& or &%ip6.arpa%& happens automatically. For example:
 configured). If no type is given, TXT is assumed. When the type is PTR,
 the data can be an IP address, written as normal; inversion and the addition of
 &%in-addr.arpa%& or &%ip6.arpa%& happens automatically. For example:


@@ -6692,12 +6890,6 @@ ${lookup dnsdb{ptr=192.168.4.5}{$value}fail}
 If the data for a PTR record is not a syntactically valid IP address, it is not
 altered and nothing is added.
 
 If the data for a PTR record is not a syntactically valid IP address, it is not
 altered and nothing is added.
 

-.cindex "MX record" "in &(dnsdb)& lookup"
-.cindex "SRV record" "in &(dnsdb)& lookup"
-For an MX lookup, both the preference value and the host name are returned for
-each record, separated by a space. For an SRV lookup, the priority, weight,
-port, and host name are returned for each record, separated by spaces.
-

 For any record type, if multiple records are found (or, for A6 lookups, if a
 single record leads to multiple addresses), the data is returned as a
 concatenation, with newline as the default separator. The order, of course,
 For any record type, if multiple records are found (or, for A6 lookups, if a
 single record leads to multiple addresses), the data is returned as a
 concatenation, with newline as the default separator. The order, of course,


@@ -6710,18 +6902,69 @@ ${lookup dnsdb{>: a=host1.example}}
 It is permitted to specify a space as the separator character. Further
 white space is ignored.
 
 It is permitted to specify a space as the separator character. Further
 white space is ignored.
 

+.cindex "MX record" "in &(dnsdb)& lookup"
+.cindex "SRV record" "in &(dnsdb)& lookup"
+For an MX lookup, both the preference value and the host name are returned for
+each record, separated by a space. For an SRV lookup, the priority, weight,
+port, and host name are returned for each record, separated by spaces.
+An alternate field separator can be specified using a comma after the main
+separator character, followed immediately by the field separator.
+

 .cindex "TXT record" "in &(dnsdb)& lookup"
 .cindex "TXT record" "in &(dnsdb)& lookup"

+.cindex "SPF record" "in &(dnsdb)& lookup"

 For TXT records with multiple items of data, only the first item is returned,
 unless a separator for them is specified using a comma after the separator
 character followed immediately by the TXT record item separator. To concatenate
 For TXT records with multiple items of data, only the first item is returned,
 unless a separator for them is specified using a comma after the separator
 character followed immediately by the TXT record item separator. To concatenate

-items without a separator, use a semicolon instead.
+items without a separator, use a semicolon instead. For SPF records the
+default behaviour is to concatenate multiple items without using a separator.

 .code
 ${lookup dnsdb{>\n,: txt=a.b.example}}
 ${lookup dnsdb{>\n; txt=a.b.example}}
 .code
 ${lookup dnsdb{>\n,: txt=a.b.example}}
 ${lookup dnsdb{>\n; txt=a.b.example}}

+${lookup dnsdb{spf=example.org}}

 .endd
 It is permitted to specify a space as the separator character. Further
 white space is ignored.
 
 .endd
 It is permitted to specify a space as the separator character. Further
 white space is ignored.
 

+.section "Dnsdb lookup modifiers" "SECTdnsdb_mod"
+.cindex "dnsdb modifiers"
+.cindex "modifiers" "dnsdb"
+.cindex "options" "dnsdb"
+Modifiers for &(dnsdb)& lookups are givien by optional keywords,
+each followed by a comma,
+that may appear before the record type.
+
+The &(dnsdb)& lookup fails only if all the DNS lookups fail. If there is a
+temporary DNS error for any of them, the behaviour is controlled by
+a defer-option modifier.
+The possible keywords are
+&"defer_strict"&, &"defer_never"&, and &"defer_lax"&.
+With &"strict"& behaviour, any temporary DNS error causes the
+whole lookup to defer. With &"never"& behaviour, a temporary DNS error is
+ignored, and the behaviour is as if the DNS lookup failed to find anything.
+With &"lax"& behaviour, all the queries are attempted, but a temporary DNS
+error causes the whole lookup to defer only if none of the other lookups
+succeed. The default is &"lax"&, so the following lookups are equivalent:
+.code
+${lookup dnsdb{defer_lax,a=one.host.com:two.host.com}}
+${lookup dnsdb{a=one.host.com:two.host.com}}
+.endd
+Thus, in the default case, as long as at least one of the DNS lookups
+yields some data, the lookup succeeds.
+
+.cindex "DNSSEC" "dns lookup"
+Use of &(DNSSEC)& is controlled by a dnssec modifier.
+The possible keywords are
+&"dnssec_strict"&, &"dnssec_lax"&, and &"dnssec_never"&.
+With &"strict"& or &"lax"& DNSSEC information is requested
+with the lookup.
+With &"strict"& a response from the DNS resolver that
+is not labelled as authenticated data
+is treated as equivalent to a temporary DNS error.
+The default is &"never"&.
+
+See also the &$lookup_dnssec_authenticated$& variable.
+
+

 .section "Pseudo dnsdb record types" "SECID66"
 .cindex "MX record" "in &(dnsdb)& lookup"
 By default, both the preference value and the host name are returned for
 .section "Pseudo dnsdb record types" "SECID66"
 .cindex "MX record" "in &(dnsdb)& lookup"
 By default, both the preference value and the host name are returned for


@@ -6769,6 +7012,14 @@ has two space-separated fields: an authorization code and a target host name.
 The authorization code can be &"Y"& for yes, &"N"& for no, &"X"& for explicit
 authorization required but absent, or &"?"& for unknown.
 
 The authorization code can be &"Y"& for yes, &"N"& for no, &"X"& for explicit
 authorization required but absent, or &"?"& for unknown.
 

+.cindex "A+" "in &(dnsdb)& lookup"
+The pseudo-type A+ performs an A6 lookup (if configured) followed by an AAAA
+and then an A lookup.  All results are returned; defer processing
+(see below) is handled separately for each lookup.  Example:
+.code
+${lookup dnsdb {>; a+=$sender_helo_name}}
+.endd
+

 
 .section "Multiple dnsdb lookups" "SECID67"
 In the previous sections, &(dnsdb)& lookups for a single domain are described.
 
 .section "Multiple dnsdb lookups" "SECID67"
 In the previous sections, &(dnsdb)& lookups for a single domain are described.


@@ -6789,23 +7040,6 @@ The data from each lookup is concatenated, with newline separators by default,
 in the same way that multiple DNS records for a single item are handled. A
 different separator can be specified, as described above.
 
 in the same way that multiple DNS records for a single item are handled. A
 different separator can be specified, as described above.
 

-The &(dnsdb)& lookup fails only if all the DNS lookups fail. If there is a
-temporary DNS error for any of them, the behaviour is controlled by
-an optional keyword followed by a comma that may appear before the record
-type. The possible keywords are &"defer_strict"&, &"defer_never"&, and
-&"defer_lax"&. With &"strict"& behaviour, any temporary DNS error causes the
-whole lookup to defer. With &"never"& behaviour, a temporary DNS error is
-ignored, and the behaviour is as if the DNS lookup failed to find anything.
-With &"lax"& behaviour, all the queries are attempted, but a temporary DNS
-error causes the whole lookup to defer only if none of the other lookups
-succeed. The default is &"lax"&, so the following lookups are equivalent:
-.code
-${lookup dnsdb{defer_lax,a=one.host.com:two.host.com}}
-${lookup dnsdb{a=one.host.com:two.host.com}}
-.endd
-Thus, in the default case, as long as at least one of the DNS lookups
-yields some data, the lookup succeeds.
-

 
 
 
 
 
 


@@ -6870,6 +7104,16 @@ With sufficiently modern LDAP libraries, Exim supports forcing TLS over regular
 LDAP connections, rather than the SSL-on-connect &`ldaps`&.
 See the &%ldap_start_tls%& option.
 
 LDAP connections, rather than the SSL-on-connect &`ldaps`&.
 See the &%ldap_start_tls%& option.
 

+Starting with Exim 4.83, the initialization of LDAP with TLS is more tightly
+controlled. Every part of the TLS configuration can be configured by settings in
+&_exim.conf_&. Depending on the version of the client libraries installed on
+your system, some of the initialization may have required setting options in
+&_/etc/ldap.conf_& or &_~/.ldaprc_& to get TLS working with self-signed
+certificates. This revealed a nuance where the current UID that exim was
+running as could affect which config files it read. With Exim 4.83, these
+methods become optional, only taking effect if not specifically set in
+&_exim.conf_&.
+

 
 .section "LDAP quoting" "SECID68"
 .cindex "LDAP" "quoting"
 
 .section "LDAP quoting" "SECID68"
 .cindex "LDAP" "quoting"


@@ -7016,6 +7260,7 @@ them. The following names are recognized:
 &`USER       `&  set the DN, for authenticating the LDAP bind
 &`PASS       `&  set the password, likewise
 &`REFERRALS  `&  set the referrals parameter
 &`USER       `&  set the DN, for authenticating the LDAP bind
 &`PASS       `&  set the password, likewise
 &`REFERRALS  `&  set the referrals parameter

+&`SERVERS    `&  set alternate server list for this query only

 &`SIZE       `&  set the limit for the number of entries returned
 &`TIME       `&  set the maximum waiting time for a query
 .endd
 &`SIZE       `&  set the limit for the number of entries returned
 &`TIME       `&  set the maximum waiting time for a query
 .endd


@@ -7037,6 +7282,13 @@ Netscape SDK; for OpenLDAP no action is taken.
 The TIME parameter (also a number of seconds) is passed to the server to
 set a server-side limit on the time taken to complete a search.
 
 The TIME parameter (also a number of seconds) is passed to the server to
 set a server-side limit on the time taken to complete a search.
 

+The SERVERS parameter allows you to specify an alternate list of ldap servers
+to use for an individual lookup.  The global ldap_servers option provides a
+default list of ldap servers, and a single lookup can specify a single ldap
+server to use.  But when you need to do a lookup with a list of servers that is
+different than the default list (maybe different order, maybe a completely
+different set of servers), the SERVERS parameter allows you to specify this
+alternate list (colon-separated).

 
 Here is an example of an LDAP query in an Exim lookup that uses some of these
 values. This is a single line, folded to fit on the page:
 
 Here is an example of an LDAP query in an Exim lookup that uses some of these
 values. This is a single line, folded to fit on the page:


@@ -7108,30 +7360,38 @@ If you specify multiple attributes, the result contains space-separated, quoted
 strings, each preceded by the attribute name and an equals sign. Within the
 quotes, the quote character, backslash, and newline are escaped with
 backslashes, and commas are used to separate multiple values for the attribute.
 strings, each preceded by the attribute name and an equals sign. Within the
 quotes, the quote character, backslash, and newline are escaped with
 backslashes, and commas are used to separate multiple values for the attribute.

+Any commas in attribute values are doubled
+(permitting treatment of the values as a comma-separated list).

 Apart from the escaping, the string within quotes takes the same form as the
 output when a single attribute is requested. Specifying no attributes is the
 same as specifying all of an entry's attributes.
 
 Here are some examples of the output format. The first line of each pair is an
 LDAP query, and the second is the data that is returned. The attribute called
 Apart from the escaping, the string within quotes takes the same form as the
 output when a single attribute is requested. Specifying no attributes is the
 same as specifying all of an entry's attributes.
 
 Here are some examples of the output format. The first line of each pair is an
 LDAP query, and the second is the data that is returned. The attribute called

-&%attr1%& has two values, whereas &%attr2%& has only one value:
+&%attr1%& has two values, one of them with an embedded comma, whereas
+&%attr2%& has only one value:

 .code
 ldap:///o=base?attr1?sub?(uid=fred)
 .code
 ldap:///o=base?attr1?sub?(uid=fred)

-value1.1, value1.2
+value1.1,value1,,2

 
 ldap:///o=base?attr2?sub?(uid=fred)
 value two
 
 ldap:///o=base?attr1,attr2?sub?(uid=fred)
 
 ldap:///o=base?attr2?sub?(uid=fred)
 value two
 
 ldap:///o=base?attr1,attr2?sub?(uid=fred)

-attr1="value1.1, value1.2" attr2="value two"
+attr1="value1.1,value1,,2" attr2="value two"

 
 ldap:///o=base??sub?(uid=fred)
 
 ldap:///o=base??sub?(uid=fred)

-objectClass="top" attr1="value1.1, value1.2" attr2="value two"
+objectClass="top" attr1="value1.1,value1,,2" attr2="value two"

 .endd
 .endd

-The &%extract%& operator in string expansions can be used to pick out
-individual fields from data that consists of &'key'&=&'value'& pairs. You can
+You can

 make use of Exim's &%-be%& option to run expansion tests and thereby check the
 results of LDAP lookups.
 make use of Exim's &%-be%& option to run expansion tests and thereby check the
 results of LDAP lookups.

+The &%extract%& operator in string expansions can be used to pick out
+individual fields from data that consists of &'key'&=&'value'& pairs.
+The &%listextract%& operator should be used to pick out individual values
+of attributes, even when only a single value is expected.
+The doubling of embedded commas allows you to use the returned data as a
+comma separated list (using the "<," syntax for changing the input list separator).

 
 
 
 
 
 


@@ -7343,7 +7603,7 @@ ${lookup sqlite {/some/thing/sqlitedb \
 .endd
 In a list, the syntax is similar. For example:
 .code
 .endd
 In a list, the syntax is similar. For example:
 .code

-domainlist relay_domains = sqlite;/some/thing/sqlitedb \
+domainlist relay_to_domains = sqlite;/some/thing/sqlitedb \

    select * from relays where ip='$sender_host_address';
 .endd
 The only character affected by the &%quote_sqlite%& operator is a single
    select * from relays where ip='$sender_host_address';
 .endd
 The only character affected by the &%quote_sqlite%& operator is a single


@@ -7425,13 +7685,13 @@ subject is not in the set. If the end of the list is reached without the
 subject having matched any of the patterns, it is in the set if the last item
 was a negative one, but not if it was a positive one. For example, the list in
 .code
 subject having matched any of the patterns, it is in the set if the last item
 was a negative one, but not if it was a positive one. For example, the list in
 .code

-domainlist relay_domains = !a.b.c : *.b.c
+domainlist relay_to_domains = !a.b.c : *.b.c

 .endd
 matches any domain ending in &'.b.c'& except for &'a.b.c'&. Domains that match
 neither &'a.b.c'& nor &'*.b.c'& do not match, because the last item in the
 list is positive. However, if the setting were
 .code
 .endd
 matches any domain ending in &'.b.c'& except for &'a.b.c'&. Domains that match
 neither &'a.b.c'& nor &'*.b.c'& do not match, because the last item in the
 list is positive. However, if the setting were
 .code

-domainlist relay_domains = !a.b.c
+domainlist relay_to_domains = !a.b.c

 .endd
 then all domains other than &'a.b.c'& would match because the last item in the
 list is negative. In other words, a list that ends with a negative item behaves
 .endd
 then all domains other than &'a.b.c'& would match because the last item in the
 list is negative. In other words, a list that ends with a negative item behaves


@@ -7535,7 +7795,7 @@ the words &%domainlist%&, &%hostlist%&, &%addresslist%&, or &%localpartlist%&,
 respectively. Then there follows the name that you are defining, followed by an
 equals sign and the list itself. For example:
 .code
 respectively. Then there follows the name that you are defining, followed by an
 equals sign and the list itself. For example:
 .code

-hostlist    relay_hosts = 192.168.23.0/24 : my.friend.example
+hostlist    relay_from_hosts = 192.168.23.0/24 : my.friend.example

 addresslist bad_senders = cdb;/etc/badsenders
 .endd
 A named list may refer to other named lists:
 addresslist bad_senders = cdb;/etc/badsenders
 .endd
 A named list may refer to other named lists:


@@ -8002,7 +8262,7 @@ case the IP address is used on its own.
 There are several types of pattern that require Exim to know the name of the
 remote host. These are either wildcard patterns or lookups by name. (If a
 complete hostname is given without any wildcarding, it is used to find an IP
 There are several types of pattern that require Exim to know the name of the
 remote host. These are either wildcard patterns or lookups by name. (If a
 complete hostname is given without any wildcarding, it is used to find an IP

-address to match against, as described in the section &<<SECThoslispatip>>&
+address to match against, as described in section &<<SECThoslispatip>>&

 above.)
 
 If the remote host name is not already known when Exim encounters one of these
 above.)
 
 If the remote host name is not already known when Exim encounters one of these


@@ -8082,10 +8342,13 @@ apply to temporary DNS errors, whose handling is described in the next section.
 
 .cindex "&`+include_unknown`&"
 .cindex "&`+ignore_unknown`&"
 
 .cindex "&`+include_unknown`&"
 .cindex "&`+ignore_unknown`&"

-By default, Exim behaves as if the host does not match the list. This may not
-always be what you want to happen. To change Exim's behaviour, the special
-items &`+include_unknown`& or &`+ignore_unknown`& may appear in the list (at
-top level &-- they are not recognized in an indirected file).
+Exim parses a host list from left to right. If it encounters a permanent
+lookup failure in any item in the host list before it has found a match,
+Exim treats it as a failure and the default behavior is as if the host
+does not match the list. This may not always be what you want to happen.
+To change Exim's behaviour, the special items &`+include_unknown`& or
+&`+ignore_unknown`& may appear in the list (at top level &-- they are
+not recognized in an indirected file).

 
 .ilist
 If any item that follows &`+include_unknown`& requires information that
 
 .ilist
 If any item that follows &`+include_unknown`& requires information that


@@ -8113,6 +8376,42 @@ Both &`+include_unknown`& and &`+ignore_unknown`& may appear in the same
 list. The effect of each one lasts until the next, or until the end of the
 list.
 
 list. The effect of each one lasts until the next, or until the end of the
 list.
 

+.section "Mixing wildcarded host names and addresses in host lists" &&&
+         "SECTmixwilhos"
+.cindex "host list" "mixing names and addresses in"
+
+This section explains the host/ip processing logic with the same concepts
+as the previous section, but specifically addresses what happens when a
+wildcarded hostname is one of the items in the hostlist.
+
+.ilist
+If you have name lookups or wildcarded host names and
+IP addresses in the same host list, you should normally put the IP
+addresses first. For example, in an ACL you could have:
+.code
+accept hosts = 10.9.8.7 : *.friend.example
+.endd
+The reason you normally would order it this way lies in the
+left-to-right way that Exim processes lists.  It can test IP addresses
+without doing any DNS lookups, but when it reaches an item that requires
+a host name, it fails if it cannot find a host name to compare with the
+pattern. If the above list is given in the opposite order, the
+&%accept%& statement fails for a host whose name cannot be found, even
+if its IP address is 10.9.8.7.
+
+.next
+If you really do want to do the name check first, and still recognize the IP
+address, you can rewrite the ACL like this:
+.code
+accept hosts = *.friend.example
+accept hosts = 10.9.8.7
+.endd
+If the first &%accept%& fails, Exim goes on to try the second one. See chapter
+&<<CHAPACL>>& for details of ACLs. Alternatively, you can use
+&`+ignore_unknown`&, which was discussed in depth in the first example in
+this section.
+.endlist
+

 
 .section "Temporary DNS errors when looking up host information" &&&
          "SECTtemdnserr"
 
 .section "Temporary DNS errors when looking up host information" &&&
          "SECTtemdnserr"


@@ -8171,7 +8470,7 @@ use masked IP addresses in database queries, you can use the &%mask%& expansion
 operator.
 
 If the query contains a reference to &$sender_host_name$&, Exim automatically
 operator.
 
 If the query contains a reference to &$sender_host_name$&, Exim automatically

-looks up the host name if has not already done so. (See section
+looks up the host name if it has not already done so. (See section

 &<<SECThoslispatnam>>& for comments on finding host names.)
 
 Historical note: prior to release 4.30, Exim would always attempt to find a
 &<<SECThoslispatnam>>& for comments on finding host names.)
 
 Historical note: prior to release 4.30, Exim would always attempt to find a


@@ -8183,33 +8482,6 @@ See section &<<SECThoslispatsikey>>&.)
 
 
 
 
 
 

-.section "Mixing wildcarded host names and addresses in host lists" &&&
-         "SECTmixwilhos"
-.cindex "host list" "mixing names and addresses in"
-If you have name lookups or wildcarded host names and IP addresses in the same
-host list, you should normally put the IP addresses first. For example, in an
-ACL you could have:
-.code
-accept hosts = 10.9.8.7 : *.friend.example
-.endd
-The reason for this lies in the left-to-right way that Exim processes lists.
-It can test IP addresses without doing any DNS lookups, but when it reaches an
-item that requires a host name, it fails if it cannot find a host name to
-compare with the pattern. If the above list is given in the opposite order, the
-&%accept%& statement fails for a host whose name cannot be found, even if its
-IP address is 10.9.8.7.
-
-If you really do want to do the name check first, and still recognize the IP
-address, you can rewrite the ACL like this:
-.code
-accept hosts = *.friend.example
-accept hosts = 10.9.8.7
-.endd
-If the first &%accept%& fails, Exim goes on to try the second one. See chapter
-&<<CHAPACL>>& for details of ACLs.
-
-
-

 
 
 .section "Address lists" "SECTaddresslist"
 
 
 .section "Address lists" "SECTaddresslist"


@@ -8371,7 +8643,7 @@ but the separating colon must still be included at line breaks. White space
 surrounding the colons is ignored. For example:
 .code
 aol.com:  spammer1 : spammer2 : ^[0-9]+$ :
 surrounding the colons is ignored. For example:
 .code
 aol.com:  spammer1 : spammer2 : ^[0-9]+$ :

-spammer3 : spammer4
+  spammer3 : spammer4

 .endd
 As in all colon-separated lists in Exim, a colon can be included in an item by
 doubling.
 .endd
 As in all colon-separated lists in Exim, a colon can be included in an item by
 doubling.


@@ -8483,6 +8755,13 @@ start of a portion of the string that is interpreted and replaced as described
 below in section &<<SECTexpansionitems>>& onwards. Backslash is used as an
 escape character, as described in the following section.
 
 below in section &<<SECTexpansionitems>>& onwards. Backslash is used as an
 escape character, as described in the following section.
 

+Whether a string is expanded depends upon the context.  Usually this is solely
+dependent upon the option for which a value is sought; in this documentation,
+options for which string expansion is performed are marked with &dagger; after
+the data type.  ACL rules always expand strings.  A couple of expansion
+conditions do not expand some of the brace-delimited branches, for security
+reasons.
+

 
 
 .section "Literal text in expanded strings" "SECTlittext"
 
 
 .section "Literal text in expanded strings" "SECTlittext"


@@ -8609,6 +8888,88 @@ string easier to understand.
 This item inserts &"basic"& header lines. It is described with the &%header%&
 expansion item below.
 
 This item inserts &"basic"& header lines. It is described with the &%header%&
 expansion item below.
 

+
+.vitem "&*${acl{*&<&'name'&>&*}{*&<&'arg'&>&*}...}*&"
+.cindex "expansion" "calling an acl"
+.cindex "&%acl%&" "call from expansion"
+The name and zero to nine argument strings are first expanded separately.  The expanded
+arguments are assigned to the variables &$acl_arg1$& to &$acl_arg9$& in order.
+Any unused are made empty.  The variable &$acl_narg$& is set to the number of
+arguments.  The named ACL (see chapter &<<CHAPACL>>&) is called
+and may use the variables; if another acl expansion is used the values
+are restored after it returns.  If the ACL sets
+a value using a "message =" modifier and returns accept or deny, the value becomes
+the result of the expansion.
+If no message is set and the ACL returns accept or deny
+the expansion result is an empty string.
+If the ACL returns defer the result is a forced-fail.  Otherwise the expansion fails.
+
+
+.vitem "&*${certextract{*&<&'field'&>&*}{*&<&'certificate'&>&*}&&&
+       {*&<&'string2'&>&*}{*&<&'string3'&>&*}}*&"
+.cindex "expansion" "extracting cerificate fields"
+.cindex "&%certextract%&" "certificate fields"
+.cindex "certificate" "extracting fields"
+The <&'certificate'&> must be a variable of type certificate.
+The field name is expanded and used to retrive the relevant field from
+the certificate.  Supported fields are:
+.display
+&`version        `&
+&`serial_number  `&
+&`subject        `& RFC4514 DN
+&`issuer         `& RFC4514 DN
+&`notbefore      `& time
+&`notafter       `& time
+&`sig_algorithm  `&
+&`signature      `&
+&`subj_altname   `& tagged list
+&`ocsp_uri       `& list
+&`crl_uri        `& list
+.endd
+If the field is found,
+<&'string2'&> is expanded, and replaces the whole item;
+otherwise <&'string3'&> is used. During the expansion of <&'string2'&> the
+variable &$value$& contains the value that has been extracted. Afterwards, it
+is restored to any previous value it might have had.
+
+If {<&'string3'&>} is omitted, the item is replaced by an empty string if the
+key is not found. If {<&'string2'&>} is also omitted, the value that was
+extracted is used.
+
+Some field names take optional modifiers, appended and separated by commas.
+
+The field selectors marked as "RFC4514" above
+output a Distinguished Name string which is
+not quite
+parseable by Exim as a comma-separated tagged list
+(the exceptions being elements containin commas).
+RDN elements of a single type may be selected by
+a modifier of the type label; if so the expansion
+result is a list (newline-separated by default).
+The separator may be changed by another modifer of
+a right angle-bracket followed immediately by the new separator.
+Recognised RDN type labels include "CN", "O", "OU" and "DC".
+
+The field selectors marked as "time" above
+take an optional modifier of "int"
+for which the result is the number of seconds since epoch.
+Otherwise the result is a human-readable string
+in the timezone selected by the main "timezone" option.
+
+The field selectors marked as "list" above return a list,
+newline-separated by default,
+(embedded separator characters in elements are doubled).
+The separator may be changed by a modifier of
+a right angle-bracket followed immediately by the new separator.
+
+The field selectors marked as "tagged" above
+prefix each list element with a type string and an equals sign.
+Elements of only one type may be selected by a modifier
+which is one of "dns", "uri" or "mail";
+if so the elenment tags are omitted.
+
+If not otherwise noted field values are presented in human-readable form.
+

 .vitem "&*${dlfunc{*&<&'file'&>&*}{*&<&'function'&>&*}{*&<&'arg'&>&*}&&&
        {*&<&'arg'&>&*}...}*&"
 .cindex &%dlfunc%&
 .vitem "&*${dlfunc{*&<&'file'&>&*}{*&<&'function'&>&*}{*&<&'arg'&>&*}&&&
        {*&<&'arg'&>&*}...}*&"
 .cindex &%dlfunc%&


@@ -8941,6 +9302,44 @@ of <&'string2'&>, whichever is the shorter. Do not confuse &%length%& with
 &%strlen%&, which gives the length of a string.
 
 
 &%strlen%&, which gives the length of a string.
 
 

+.vitem "&*${listextract{*&<&'number'&>&*}&&&
+        {*&<&'string1'&>&*}{*&<&'string2'&>&*}{*&<&'string3'&>&*}}*&"
+.cindex "expansion" "extracting list elements by number"
+.cindex "&%listextract%&" "extract list elements by number"
+.cindex "list" "extracting elements by number"
+The <&'number'&> argument must consist entirely of decimal digits,
+apart from an optional leading minus,
+and leading and trailing white space (which is ignored).
+
+After expansion, <&'string1'&> is interpreted as a list, colon-separated by
+default, but the separator can be changed in the usual way.
+
+The first field of the list is numbered one.
+If the number is negative, the fields are
+counted from the end of the list, with the rightmost one numbered -1.
+The numbered element of the list is extracted and placed in &$value$&,
+then <&'string2'&> is expanded as the result.
+
+If the modulus of the
+number is zero or greater than the number of fields in the string,
+the result is the expansion of <&'string3'&>.
+
+For example:
+.code
+${listextract{2}{x:42:99}}
+.endd
+yields &"42"&, and
+.code
+${listextract{-3}{<, x,42,99,& Mailer,,/bin/bash}{result: $value}}
+.endd
+yields &"result: 99"&.
+
+If {<&'string3'&>} is omitted, an empty string is used for string3.
+If {<&'string2'&>} is also omitted, the value that was
+extracted is used.
+You can use &`fail`& instead of {<&'string3'&>} as in a string extract.
+
+

 .vitem "&*${lookup{*&<&'key'&>&*}&~*&<&'search&~type'&>&*&~&&&
         {*&<&'file'&>&*}&~{*&<&'string1'&>&*}&~{*&<&'string2'&>&*}}*&"
 This is the first of one of two different types of lookup item, which are both
 .vitem "&*${lookup{*&<&'key'&>&*}&~*&<&'search&~type'&>&*&~&&&
         {*&<&'file'&>&*}&~{*&<&'string1'&>&*}&~{*&<&'string2'&>&*}}*&"
 This is the first of one of two different types of lookup item, which are both


@@ -9122,7 +9521,7 @@ locks out the use of this expansion item in filter files.
 .cindex "expansion" "inserting from a socket"
 .cindex "socket, use of in expansion"
 .cindex "&%readsocket%& expansion item"
 .cindex "expansion" "inserting from a socket"
 .cindex "socket, use of in expansion"
 .cindex "&%readsocket%& expansion item"

-This item inserts data from a Unix domain or Internet socket into the expanded
+This item inserts data from a Unix domain or TCP socket into the expanded

 string. The minimal way of using it uses just two arguments, as in these
 examples:
 .code
 string. The minimal way of using it uses just two arguments, as in these
 examples:
 .code


@@ -9218,11 +9617,23 @@ expansion item above.
         {*&<&'string2'&>&*}}*&"
 .cindex "expansion" "running a command"
 .cindex "&%run%& expansion item"
         {*&<&'string2'&>&*}}*&"
 .cindex "expansion" "running a command"
 .cindex "&%run%& expansion item"

-The command and its arguments are first expanded separately, and then the
-command is run in a separate process, but under the same uid and gid. As in
-other command executions from Exim, a shell is not used by default. If you want
+The command and its arguments are first expanded as one string. The string is
+split apart into individual arguments by spaces, and then the command is run
+in a separate process, but under the same uid and gid.  As in other command
+executions from Exim, a shell is not used by default. If the command requires

 a shell, you must explicitly code it.
 
 a shell, you must explicitly code it.
 

+Since the arguments are split by spaces, when there is a variable expansion
+which has an empty result, it will cause the situation that the argument will
+simply be omitted when the program is actually executed by Exim. If the
+script/program requires a specific number of arguments and the expanded
+variable could possibly result in this empty expansion, the variable must be
+quoted. This is more difficult if the expanded variable itself could result
+in a string containing quotes, because it would interfere with the quotes
+around the command arguments. A possible guard against this is to wrap the
+variable in the &%sg%& operator to change any quote marks to some other
+character.
+

 The standard input for the command exists, but is empty. The standard output
 and standard error are set to the same file descriptor.
 .cindex "return code" "from &%run%& expansion"
 The standard input for the command exists, but is empty. The standard output
 and standard error are set to the same file descriptor.
 .cindex "return code" "from &%run%& expansion"


@@ -9239,6 +9650,20 @@ can be the word &"fail"& (not in braces) to force expansion failure if the
 command does not succeed. If both strings are omitted, the result is contents
 of the standard output/error on success, and nothing on failure.
 
 command does not succeed. If both strings are omitted, the result is contents
 of the standard output/error on success, and nothing on failure.
 

+.vindex "&$run_in_acl$&"
+The standard output/error of the command is put in the variable &$value$&.
+In this ACL example, the output of a command is logged for the admin to
+troubleshoot:
+.code
+warn  condition    = ${run{/usr/bin/id}{yes}{no}}
+      log_message  = Output of id: $value
+.endd
+If the command requires shell idioms, such as the > redirect operator, the
+shell must be invoked directly, such as with:
+.code
+${run{/bin/bash -c "/usr/bin/id >/tmp/id"}{yes}{yes}}
+.endd
+

 .vindex "&$runrc$&"
 The return code from the command is put in the variable &$runrc$&, and this
 remains set afterwards, so in a filter file you can do things like this:
 .vindex "&$runrc$&"
 The return code from the command is put in the variable &$runrc$&, and this
 remains set afterwards, so in a filter file you can do things like this:


@@ -9287,6 +9712,35 @@ the regular expression from string expansion.
 
 
 
 
 
 

+.vitem &*${sort{*&<&'string'&>&*}{*&<&'comparator'&>&*}{*&<&'extractor'&>&*}}*&
+.cindex sorting a list
+.cindex list sorting
+After expansion, <&'string'&> is interpreted as a list, colon-separated by
+default, but the separator can be changed in the usual way.
+The <&'comparator'&> argument is interpreted as the operator
+of a two-argument expansion condition.
+The numeric operators plus ge, gt, le, lt (and ~i variants) are supported.
+The comparison should return true when applied to two values
+if the first value should sort before the second value.
+The <&'extractor'&> expansion is applied repeatedly to elements of the list,
+the element being placed in &$item$&,
+to give values for comparison.
+
+The item result is a sorted list,
+with the original list separator,
+of the list elements (in full) of the original.
+
+Examples:
+.code
+${sort{3:2:1:4}{<}{$item}}
+.endd
+sorts a list of numbers, and
+.code
+${sort {${lookup dnsdb{>:,,mx=example.com}}} {<} {${listextract{1}{<,$item}}}}
+.endd
+will sort an MX lookup into priority order.
+
+

 .vitem &*${substr{*&<&'string1'&>&*}{*&<&'string2'&>&*}{*&<&'string3'&>&*}}*&
 .cindex "&%substr%& expansion item"
 .cindex "substring extraction"
 .vitem &*${substr{*&<&'string1'&>&*}{*&<&'string2'&>&*}{*&<&'string3'&>&*}}*&
 .cindex "&%substr%& expansion item"
 .cindex "substring extraction"


@@ -9399,6 +9853,29 @@ expansion item, which extracts the working address from a single RFC2822
 address. See the &*filter*&, &*map*&, and &*reduce*& items for ways of
 processing lists.
 
 address. See the &*filter*&, &*map*&, and &*reduce*& items for ways of
 processing lists.
 

+To clarify "list of addresses in RFC 2822 format" mentioned above, Exim follows
+a strict interpretation of header line formatting.  Exim parses the bare,
+unquoted portion of an email address and if it finds a comma, treats it as an
+email address seperator. For the example header line:
+.code
+From: =?iso-8859-2?Q?Last=2C_First?= <user@example.com>
+.endd
+The first example below demonstrates that Q-encoded email addresses are parsed
+properly if it is given the raw header (in this example, &`$rheader_from:`&).
+It does not see the comma because it's still encoded as "=2C".  The second
+example below is passed the contents of &`$header_from:`&, meaning it gets
+de-mimed. Exim sees the decoded "," so it treats it as &*two*& email addresses.
+The third example shows that the presence of a comma is skipped when it is
+quoted.
+.code
+# exim -be '${addresses:From: \
+=?iso-8859-2?Q?Last=2C_First?= <user@example.com>}'
+user@example.com
+# exim -be '${addresses:From: Last, First <user@example.com>}'
+Last:user@example.com
+# exim -be '${addresses:From: "Last, First" <user@example.com>}'
+user@example.com
+.endd

 
 .vitem &*${base62:*&<&'digits'&>&*}*&
 .cindex "&%base62%& expansion item"
 
 .vitem &*${base62:*&<&'digits'&>&*}*&
 .cindex "&%base62%& expansion item"


@@ -9418,6 +9895,7 @@ environments where Exim uses base 36 instead of base 62 for its message
 identifiers, base-36 digits. The number is converted to decimal and output as a
 string.
 
 identifiers, base-36 digits. The number is converted to decimal and output as a
 string.
 

+

 .vitem &*${domain:*&<&'string'&>&*}*&
 .cindex "domain" "extraction"
 .cindex "expansion" "domain extraction"
 .vitem &*${domain:*&<&'string'&>&*}*&
 .cindex "domain" "extraction"
 .cindex "expansion" "domain extraction"


@@ -9462,9 +9940,10 @@ decimal, even if they start with a leading zero; hexadecimal numbers are not
 permitted. This can be useful when processing numbers extracted from dates or
 times, which often do have leading zeros.
 
 permitted. This can be useful when processing numbers extracted from dates or
 times, which often do have leading zeros.
 

-A number may be followed by &"K"& or &"M"& to multiply it by 1024 or 1024*1024,
+A number may be followed by &"K"&, &"M"& or &"G"& to multiply it by 1024, 1024*1024
+or 1024*1024*1024,

 respectively. Negative numbers are supported. The result of the computation is
 respectively. Negative numbers are supported. The result of the computation is

-a decimal representation of the answer (without &"K"& or &"M"&). For example:
+a decimal representation of the answer (without &"K"&, &"M"& or &"G"&). For example:

 
 .display
 &`${eval:1+1}            `&  yields 2
 
 .display
 &`${eval:1+1}            `&  yields 2


@@ -9551,6 +10030,16 @@ This operator converts a hex string into one that is base64 encoded. This can
 be useful for processing the output of the MD5 and SHA-1 hashing functions.
 
 
 be useful for processing the output of the MD5 and SHA-1 hashing functions.
 
 

+
+.vitem &*${hexquote:*&<&'string'&>&*}*&
+.cindex "quoting" "hex-encoded unprintable characters"
+.cindex "&%hexquote%& expansion item"
+This operator converts non-printable characters in a string into a hex
+escape form. Byte values between 33 (!) and 126 (~) inclusive are left
+as is, and other byte values are converted to &`\xNN`&, for example a
+byte value 127 is converted to &`\x7f`&.
+
+

 .vitem &*${lc:*&<&'string'&>&*}*&
 .cindex "case forcing in strings"
 .cindex "string" "case forcing"
 .vitem &*${lc:*&<&'string'&>&*}*&
 .cindex "case forcing in strings"
 .cindex "string" "case forcing"


@@ -9576,6 +10065,25 @@ See the description of the general &%length%& item above for details. Note that
 when &%length%& is used as an operator.
 
 
 when &%length%& is used as an operator.
 
 

+.vitem &*${listcount:*&<&'string'&>&*}*&
+.cindex "expansion" "list item count"
+.cindex "list" "item count"
+.cindex "list" "count of items"
+.cindex "&%listcount%& expansion item"
+The string is interpreted as a list and the number of items is returned.
+
+
+.vitem &*${listnamed:*&<&'name'&>&*}*&&~and&~&*${listnamed_*&<&'type'&>&*:*&<&'name'&>&*}*&
+.cindex "expansion" "named list"
+.cindex "&%listnamed%& expansion item"
+The name is interpreted as a named list and the content of the list is returned,
+expanding any referenced lists, re-quoting as needed for colon-separation.
+If the optional type is given it must be one of "a", "d", "h" or "l"
+and selects address-, domain-, host- or localpart- lists to search among respectively.
+Otherwise all types are searched in an undefined order and the first
+matching list is returned.
+
+

 .vitem &*${local_part:*&<&'string'&>&*}*&
 .cindex "expansion" "local part extraction"
 .cindex "&%local_part%& expansion item"
 .vitem &*${local_part:*&<&'string'&>&*}*&
 .cindex "expansion" "local part extraction"
 .cindex "&%local_part%& expansion item"


@@ -9615,6 +10123,7 @@ Letters in IPv6 addresses are always output in lower case.
 .vitem &*${md5:*&<&'string'&>&*}*&
 .cindex "MD5 hash"
 .cindex "expansion" "MD5 hash"
 .vitem &*${md5:*&<&'string'&>&*}*&
 .cindex "MD5 hash"
 .cindex "expansion" "MD5 hash"

+.cindex "certificate fingerprint"

 .cindex "&%md5%& expansion item"
 The &%md5%& operator computes the MD5 hash value of the string, and returns it
 as a 32-digit hexadecimal number, in which any letters are in lower case.
 .cindex "&%md5%& expansion item"
 The &%md5%& operator computes the MD5 hash value of the string, and returns it
 as a 32-digit hexadecimal number, in which any letters are in lower case.


@@ -9683,6 +10192,8 @@ This operator returns a somewhat random number which is less than the
 supplied number and is at least 0.  The quality of this randomness depends
 on how Exim was built; the values are not suitable for keying material.
 If Exim is linked against OpenSSL then RAND_pseudo_bytes() is used.
 supplied number and is at least 0.  The quality of this randomness depends
 on how Exim was built; the values are not suitable for keying material.
 If Exim is linked against OpenSSL then RAND_pseudo_bytes() is used.

+If Exim is linked against GnuTLS then gnutls_rnd(GNUTLS_RND_NONCE) is used,
+for versions of GnuTLS with that function.

 Otherwise, the implementation may be arc4random(), random() seeded by
 srandomdev() or srandom(), or a custom implementation even weaker than
 random().
 Otherwise, the implementation may be arc4random(), random() seeded by
 srandomdev() or srandom(), or a custom implementation even weaker than
 random().


@@ -9695,11 +10206,13 @@ dotted-quad decimal form, while for IPv6 addreses the result is in
 dotted-nibble hexadecimal form.  In both cases, this is the "natural" form
 for DNS.  For example,
 .code
 dotted-nibble hexadecimal form.  In both cases, this is the "natural" form
 for DNS.  For example,
 .code

-${reverse_ip:192.0.2.4} and ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
+${reverse_ip:192.0.2.4}
+${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.127}

 .endd
 returns
 .code
 .endd
 returns
 .code

-4.2.0.192 and 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
+4.2.0.192
+f.7.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2

 .endd
 
 
 .endd
 
 


@@ -9748,11 +10261,24 @@ variables or headers inside regular expressions.
 .vitem &*${sha1:*&<&'string'&>&*}*&
 .cindex "SHA-1 hash"
 .cindex "expansion" "SHA-1 hashing"
 .vitem &*${sha1:*&<&'string'&>&*}*&
 .cindex "SHA-1 hash"
 .cindex "expansion" "SHA-1 hashing"

+.cindex "certificate fingerprint"

 .cindex "&%sha2%& expansion item"
 The &%sha1%& operator computes the SHA-1 hash value of the string, and returns
 it as a 40-digit hexadecimal number, in which any letters are in upper case.
 
 
 .cindex "&%sha2%& expansion item"
 The &%sha1%& operator computes the SHA-1 hash value of the string, and returns
 it as a 40-digit hexadecimal number, in which any letters are in upper case.
 
 

+.vitem &*${sha256:*&<&'certificate'&>&*}*&
+.cindex "SHA-256 hash"
+.cindex "certificate fingerprint"
+.cindex "expansion" "SHA-256 hashing"
+.cindex "&%sha256%& expansion item"
+The &%sha256%& operator computes the SHA-256 hash fingerprint of the
+certificate,
+and returns
+it as a 64-digit hexadecimal number, in which any letters are in upper case.
+Only arguments which are a single variable of certificate type are supported.
+
+

 .vitem &*${stat:*&<&'string'&>&*}*&
 .cindex "expansion" "statting a file"
 .cindex "file" "extracting characteristics"
 .vitem &*${stat:*&<&'string'&>&*}*&
 .cindex "expansion" "statting a file"
 .cindex "file" "extracting characteristics"


@@ -9821,6 +10347,14 @@ number of larger units and output in Exim's normal time format, for example,
 .cindex "expansion" "case forcing"
 .cindex "&%uc%& expansion item"
 This forces the letters in the string into upper-case.
 .cindex "expansion" "case forcing"
 .cindex "&%uc%& expansion item"
 This forces the letters in the string into upper-case.

+
+.vitem &*${utf8clean:*&<&'string'&>&*}*&
+.cindex "correction of invalid utf-8 sequences in strings"
+.cindex "utf-8" "utf-8 sequences"
+.cindex "incorrect utf-8"
+.cindex "expansion" "utf-8 forcing"
+.cindex "&%utf8clean%& expansion item"
+This replaces any invalid utf-8 sequence in the string by the character &`?`&.

 .endlist
 
 
 .endlist
 
 


@@ -9859,18 +10393,37 @@ ${if >{$message_size}{10M} ...
 .endd
 Note that the general negation operator provides for inequality testing. The
 two strings must take the form of optionally signed decimal integers,
 .endd
 Note that the general negation operator provides for inequality testing. The
 two strings must take the form of optionally signed decimal integers,

-optionally followed by one of the letters &"K"& or &"M"& (in either upper or
-lower case), signifying multiplication by 1024 or 1024*1024, respectively.
+optionally followed by one of the letters &"K"&, &"M"& or &"G"& (in either upper or
+lower case), signifying multiplication by 1024, 1024*1024 or 1024*1024*1024, respectively.

 As a special case, the numerical value of an empty string is taken as
 zero.
 
 As a special case, the numerical value of an empty string is taken as
 zero.
 

+In all cases, a relative comparator OP is testing if <&'string1'&> OP
+<&'string2'&>; the above example is checking if &$message_size$& is larger than
+10M, not if 10M is larger than &$message_size$&.
+
+
+.vitem &*acl&~{{*&<&'name'&>&*}{*&<&'arg1'&>&*}&&&
+       {*&<&'arg2'&>&*}...}*&
+.cindex "expansion" "calling an acl"
+.cindex "&%acl%&" "expansion condition"
+The name and zero to nine argument strings are first expanded separately.  The expanded
+arguments are assigned to the variables &$acl_arg1$& to &$acl_arg9$& in order.
+Any unused are made empty.  The variable &$acl_narg$& is set to the number of
+arguments.  The named ACL (see chapter &<<CHAPACL>>&) is called
+and may use the variables; if another acl expansion is used the values
+are restored after it returns.  If the ACL sets
+a value using a "message =" modifier the variable $value becomes
+the result of the expansion, otherwise it is empty.
+If the ACL returns accept the condition is true; if deny, false.
+If the ACL returns defer the result is a forced-fail.

 
 .vitem &*bool&~{*&<&'string'&>&*}*&
 .cindex "expansion" "boolean parsing"
 .cindex "&%bool%& expansion condition"
 This condition turns a string holding a true or false representation into
 a boolean state.  It parses &"true"&, &"false"&, &"yes"& and &"no"&
 
 .vitem &*bool&~{*&<&'string'&>&*}*&
 .cindex "expansion" "boolean parsing"
 .cindex "&%bool%& expansion condition"
 This condition turns a string holding a true or false representation into
 a boolean state.  It parses &"true"&, &"false"&, &"yes"& and &"no"&

-(case-insensitively); also positive integer numbers map to true if non-zero,
+(case-insensitively); also integer numbers map to true if non-zero,

 false if zero.
 An empty string is treated as false.
 Leading and trailing whitespace is ignored;
 false if zero.
 An empty string is treated as false.
 Leading and trailing whitespace is ignored;


@@ -10059,6 +10612,8 @@ ${if forany{<, $recipients}{match{$item}{^user3@}}{yes}{no}}
 The value of &$item$& is saved and restored while &*forany*& or &*forall*& is
 being processed, to enable these expansion items to be nested.
 
 The value of &$item$& is saved and restored while &*forany*& or &*forall*& is
 being processed, to enable these expansion items to be nested.
 

+To scan a named list, expand it with the &*listnamed*& operator.
+

 
 .vitem &*ge&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*& &&&
        &*gei&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&
 
 .vitem &*ge&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*& &&&
        &*gei&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&


@@ -10082,7 +10637,6 @@ string is lexically greater than the second string. For &%gt%& the comparison
 includes the case of letters, whereas for &%gti%& the comparison is
 case-independent.
 
 includes the case of letters, whereas for &%gti%& the comparison is
 case-independent.
 

-.new

 .vitem &*inlist&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*& &&&
        &*inlisti&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&
 .cindex "string" "comparison"
 .vitem &*inlist&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*& &&&
        &*inlisti&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&
 .cindex "string" "comparison"


@@ -10099,7 +10653,6 @@ ${if inlist{needle}{foo:needle:bar}}
 ${if inlisti{Needle}{fOo:NeeDLE:bAr}}
   ${if forany{fOo:NeeDLE:bAr}{eqi{$item}{Needle}}}
 .endd
 ${if inlisti{Needle}{fOo:NeeDLE:bAr}}
   ${if forany{fOo:NeeDLE:bAr}{eqi{$item}{Needle}}}
 .endd

-.wen

 
 .vitem &*isip&~{*&<&'string'&>&*}*&  &&&
        &*isip4&~{*&<&'string'&>&*}*& &&&
 
 .vitem &*isip&~{*&<&'string'&>&*}*&  &&&
        &*isip4&~{*&<&'string'&>&*}*& &&&


@@ -10211,12 +10764,10 @@ See &*match_local_part*&.
 
 .vitem &*match_ip&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&
 .cindex "&%match_ip%& expansion condition"
 
 .vitem &*match_ip&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&
 .cindex "&%match_ip%& expansion condition"

-.new

 This condition matches an IP address to a list of IP address patterns. It must
 be followed by two argument strings. The first (after expansion) must be an IP
 address or an empty string. The second (not expanded) is a restricted host
 list that can match only an IP address, not a host name. For example:
 This condition matches an IP address to a list of IP address patterns. It must
 be followed by two argument strings. The first (after expansion) must be an IP
 address or an empty string. The second (not expanded) is a restricted host
 list that can match only an IP address, not a host name. For example:

-.wen

 .code
 ${if match_ip{$sender_host_address}{1.2.3.4:5.6.7.8}{...}{...}}
 .endd
 .code
 ${if match_ip{$sender_host_address}{1.2.3.4:5.6.7.8}{...}{...}}
 .endd


@@ -10262,10 +10813,8 @@ just as easy to use the fact that a lookup is itself a condition, and write:
 .endd
 .endlist ilist
 
 .endd
 .endlist ilist
 

-.new

 Note that <&'string2'&> is not itself subject to string expansion, unless
 Exim was built with the EXPAND_LISTMATCH_RHS option.
 Note that <&'string2'&> is not itself subject to string expansion, unless
 Exim was built with the EXPAND_LISTMATCH_RHS option.

-.wen

 
 Consult section &<<SECThoslispatip>>& for further details of these patterns.
 
 
 Consult section &<<SECThoslispatip>>& for further details of these patterns.
 


@@ -10294,10 +10843,8 @@ item can be used, as in all address lists, to cause subsequent items to
 have their local parts matched casefully. Domains are always matched
 caselessly.
 
 have their local parts matched casefully. Domains are always matched
 caselessly.
 

-.new

 Note that <&'string2'&> is not itself subject to string expansion, unless
 Exim was built with the EXPAND_LISTMATCH_RHS option.
 Note that <&'string2'&> is not itself subject to string expansion, unless
 Exim was built with the EXPAND_LISTMATCH_RHS option.

-.wen

 
 &*Note*&: Host lists are &'not'& supported in this way. This is because
 hosts have two identities: a name and an IP address, and it is not clear
 
 &*Note*&: Host lists are &'not'& supported in this way. This is because
 hosts have two identities: a name and an IP address, and it is not clear


@@ -10511,6 +11058,11 @@ precedes the expansion of the string. For example, the commands available in
 Exim filter files include an &%if%& command with its own regular expression
 matching condition.
 
 Exim filter files include an &%if%& command with its own regular expression
 matching condition.
 

+.vitem "&$acl_arg1$&, &$acl_arg2$&, etc"
+Within an acl condition, expansion condition or expansion item
+any arguments are copied to these variables,
+any unused variables being made empty.
+

 .vitem "&$acl_c...$&"
 Values can be placed in these variables by the &%set%& modifier in an ACL. They
 can be given any name that starts with &$acl_c$& and is at least six characters
 .vitem "&$acl_c...$&"
 Values can be placed in these variables by the &%set%& modifier in an ACL. They
 can be given any name that starts with &$acl_c$& and is at least six characters


@@ -10532,6 +11084,10 @@ message is received, the values of these variables are saved with the message,
 and can be accessed by filters, routers, and transports during subsequent
 delivery.
 
 and can be accessed by filters, routers, and transports during subsequent
 delivery.
 

+.vitem &$acl_narg$&
+Within an acl condition, expansion condition or expansion item
+this variable has the number of arguments.
+

 .vitem &$acl_verify_message$&
 .vindex "&$acl_verify_message$&"
 After an address verification has failed, this variable contains the failure
 .vitem &$acl_verify_message$&
 .vindex "&$acl_verify_message$&"
 After an address verification has failed, this variable contains the failure


@@ -10610,7 +11166,16 @@ the value of &$authenticated_id$& is normally the login name of the calling
 process. However, a trusted user can override this by means of the &%-oMai%&
 command line option.
 
 process. However, a trusted user can override this by means of the &%-oMai%&
 command line option.
 

-
+.vitem &$authenticated_fail_id$&
+.cindex "authentication" "fail" "id"
+.vindex "&$authenticated_fail_id$&"
+When an authentication attempt fails, the variable &$authenticated_fail_id$&
+will contain the failed authentication id. If more than one authentication
+id is attempted, it will contain only the last one. The variable is
+available for processing in the ACL's, generally the quit or notquit ACL.
+A message to a local recipient could still be accepted without requiring
+authentication, which means this variable could also be visible in all of
+the ACL's as well.

 
 
 .vitem &$authenticated_sender$&
 
 
 .vitem &$authenticated_sender$&


@@ -10644,14 +11209,12 @@ is empty and &$authentication_failed$& is set to &"1"&). Failure includes any
 negative response to an AUTH command, including (for example) an attempt to use
 an undefined mechanism.
 
 negative response to an AUTH command, including (for example) an attempt to use
 an undefined mechanism.
 

-.new

 .vitem &$av_failed$&
 .cindex "content scanning" "AV scanner failure"
 This variable is available when Exim is compiled with the content-scanning
 extension. It is set to &"0"& by default, but will be set to &"1"& if any
 problem occurs with the virus scanner (specified by &%av_scanner%&) during
 the ACL malware condition.
 .vitem &$av_failed$&
 .cindex "content scanning" "AV scanner failure"
 This variable is available when Exim is compiled with the content-scanning
 extension. It is set to &"0"& by default, but will be set to &"1"& if any
 problem occurs with the virus scanner (specified by &%av_scanner%&) during
 the ACL malware condition.

-.wen

 
 .vitem &$body_linecount$&
 .cindex "message body" "line count"
 
 .vitem &$body_linecount$&
 .cindex "message body" "line count"


@@ -10706,6 +11269,19 @@ The building process for Exim keeps a count of the number
 of times it has been compiled. This serves to distinguish different
 compilations of the same version of the program.
 
 of times it has been compiled. This serves to distinguish different
 compilations of the same version of the program.
 

+.new
+.vitem &$config_dir$&
+.vindex "&$config_dir$&"
+The directory name of the main configuration file. That is, the content of
+&$config_file$& with the last component stripped. The value does not
+contain the trailing slash. If &$config_file$& does not contain a slash,
+&$config_dir$& is ".".
+
+.vitem &$config_file$&
+.vindex "&$config_file$&"
+The name of the main configuration file Exim is using.
+.wen
+

 .vitem &$demime_errorlevel$&
 .vindex "&$demime_errorlevel$&"
 This variable is available when Exim is compiled with
 .vitem &$demime_errorlevel$&
 .vindex "&$demime_errorlevel$&"
 This variable is available when Exim is compiled with


@@ -10813,6 +11389,15 @@ This variable contains the path to the Exim binary.
 .vindex "&$exim_uid$&"
 This variable contains the numerical value of the Exim user id.
 
 .vindex "&$exim_uid$&"
 This variable contains the numerical value of the Exim user id.
 

+.new
+.vitem &$exim_version$&
+.vindex "&$exim_uid$&"
+This variable contains the version string of the Exim build.
+The first character is a major version number, currently 4.
+Then after a dot, the next group of digits is a minor version number.
+There may be other characters following the minor version.
+.wen
+

 .vitem &$found_extension$&
 .vindex "&$found_extension$&"
 This variable is available when Exim is compiled with the
 .vitem &$found_extension$&
 .vindex "&$found_extension$&"
 This variable is available when Exim is compiled with the


@@ -10825,6 +11410,12 @@ inserting the message header line with the given name. Note that the name must
 be terminated by colon or white space, because it may contain a wide variety of
 characters. Note also that braces must &'not'& be used.
 
 be terminated by colon or white space, because it may contain a wide variety of
 characters. Note also that braces must &'not'& be used.
 

+.vitem &$headers_added$&
+.vindex "&$headers_added$&"
+Within an ACL this variable contains the headers added so far by
+the ACL modifier add_header (section &<<SECTaddheadacl>>&).
+The headers are a newline-separated list.
+

 .vitem &$home$&
 .vindex "&$home$&"
 When the &%check_local_user%& option is set for a router, the user's home
 .vitem &$home$&
 .vindex "&$home$&"
 When the &%check_local_user%& option is set for a router, the user's home


@@ -10905,6 +11496,11 @@ the result, the name is not accepted, and &$host_lookup_deferred$& is set to
 .vindex "&$host_lookup_failed$&"
 See &$host_lookup_deferred$&.
 
 .vindex "&$host_lookup_failed$&"
 See &$host_lookup_deferred$&.
 

+.vitem &$host_port$&
+.vindex "&$host_port$&"
+This variable is set to the remote host's TCP port whenever &$host$& is set
+for an outbound connection.
+

 
 .vitem &$inode$&
 .vindex "&$inode$&"
 
 .vitem &$inode$&
 .vindex "&$inode$&"


@@ -11057,6 +11653,14 @@ ability to find the amount of free space (only true for experimental systems),
 the space value is -1. See also the &%check_log_space%& option.
 
 
 the space value is -1. See also the &%check_log_space%& option.
 
 

+.vitem &$lookup_dnssec_authenticated$&
+.vindex "&$lookup_dnssec_authenticated$&"
+This variable is set after a DNS lookup done by
+a dnsdb lookup expansion, dnslookup router or smtp transport.
+It will be empty if &(DNSSEC)& was not requested,
+&"no"& if the result was not labelled as authenticated data
+and &"yes"& if it was.
+

 .vitem &$mailstore_basename$&
 .vindex "&$mailstore_basename$&"
 This variable is set only when doing deliveries in &"mailstore"& format in the
 .vitem &$mailstore_basename$&
 .vindex "&$mailstore_basename$&"
 This variable is set only when doing deliveries in &"mailstore"& format in the


@@ -11143,7 +11747,7 @@ This variable is like &$message_headers$& except that no processing of the
 contents of header lines is done.
 
 .vitem &$message_id$&
 contents of header lines is done.
 
 .vitem &$message_id$&

-This is an old name for &$message_exim_id$&, which is now deprecated.
+This is an old name for &$message_exim_id$&. It is now deprecated.

 
 .vitem &$message_linecount$&
 .vindex "&$message_linecount$&"
 
 .vitem &$message_linecount$&
 .vindex "&$message_linecount$&"


@@ -11360,10 +11964,7 @@ on which interface and/or port is being used for the incoming connection. The
 values of &$received_ip_address$& and &$received_port$& are saved with any
 messages that are received, thus making these variables available at delivery
 time.
 values of &$received_ip_address$& and &$received_port$& are saved with any
 messages that are received, thus making these variables available at delivery
 time.

-
-&*Note:*& There are no equivalent variables for outgoing connections, because
-the values are unknown (unless they are explicitly set by options of the
-&(smtp)& transport).
+For outbound connections see &$sending_ip_address$&.

 
 .vitem &$received_port$&
 .vindex "&$received_port$&"
 
 .vitem &$received_port$&
 .vindex "&$received_port$&"


@@ -11495,6 +12096,12 @@ envelope sender.
 .vindex "&$return_size_limit$&"
 This is an obsolete name for &$bounce_return_size_limit$&.
 
 .vindex "&$return_size_limit$&"
 This is an obsolete name for &$bounce_return_size_limit$&.
 

+.vitem &$router_name$&
+.cindex "router" "name"
+.cindex "name" "of router"
+.vindex "&$router_name$&"
+During the running of a router this variable contains its name.
+

 .vitem &$runrc$&
 .cindex "return code" "from &%run%& expansion"
 .vindex "&$runrc$&"
 .vitem &$runrc$&
 .cindex "return code" "from &%run%& expansion"
 .vindex "&$runrc$&"


@@ -11576,8 +12183,9 @@ the &%-bs%& or &%-bS%& options.
 
 .vitem &$sender_host_address$&
 .vindex "&$sender_host_address$&"
 
 .vitem &$sender_host_address$&
 .vindex "&$sender_host_address$&"

-When a message is received from a remote host, this variable contains that
-host's IP address. For locally submitted messages, it is empty.
+When a message is received from a remote host using SMTP,
+this variable contains that
+host's IP address. For locally non-SMTP submitted messages, it is empty.

 
 .vitem &$sender_host_authenticated$&
 .vindex "&$sender_host_authenticated$&"
 
 .vitem &$sender_host_authenticated$&
 .vindex "&$sender_host_authenticated$&"


@@ -11586,6 +12194,30 @@ driver that successfully authenticated the client from which the message was
 received. It is empty if there was no successful authentication. See also
 &$authenticated_id$&.
 
 received. It is empty if there was no successful authentication. See also
 &$authenticated_id$&.
 

+.vitem &$sender_host_dnssec$&
+.vindex "&$sender_host_dnssec$&"
+If an attempt to populate &$sender_host_name$& has been made
+(by reference, &%hosts_lookup%& or
+otherwise) then this boolean will have been set true if, and only if, the
+resolver library states that the reverse DNS was authenticated data.  At all
+other times, this variable is false.
+
+It is likely that you will need to coerce DNSSEC support on in the resolver
+library, by setting:
+.code
+dns_dnssec_ok = 1
+.endd
+
+Exim does not perform DNSSEC validation itself, instead leaving that to a
+validating resolver (eg, unbound, or bind with suitable configuration).
+
+Exim does not (currently) check to see if the forward DNS was also secured
+with DNSSEC, only the reverse DNS.
+
+If you have changed &%host_lookup_order%& so that &`bydns`& is not the first
+mechanism in the list, then this variable will be false.
+
+

 .vitem &$sender_host_name$&
 .vindex "&$sender_host_name$&"
 When a message is received from a remote host, this variable contains the
 .vitem &$sender_host_name$&
 .vindex "&$sender_host_name$&"
 When a message is received from a remote host, this variable contains the


@@ -11784,12 +12416,73 @@ command in a filter file. Its use is explained in the description of that
 command, which can be found in the separate document entitled &'Exim's
 interfaces to mail filtering'&.
 
 command, which can be found in the separate document entitled &'Exim's
 interfaces to mail filtering'&.
 

-.vitem &$tls_certificate_verified$&
-.vindex "&$tls_certificate_verified$&"
+.vitem &$tls_in_bits$&
+.vindex "&$tls_in_bits$&"
+Contains an approximation of the TLS cipher's bit-strength
+on the inbound connection; the meaning of
+this depends upon the TLS implementation used.
+If TLS has not been negotiated, the value will be 0.
+The value of this is automatically fed into the Cyrus SASL authenticator
+when acting as a server, to specify the "external SSF" (a SASL term).
+
+The deprecated &$tls_bits$& variable refers to the inbound side
+except when used in the context of an outbound SMTP delivery, when it refers to
+the outbound.
+
+.vitem &$tls_out_bits$&
+.vindex "&$tls_out_bits$&"
+Contains an approximation of the TLS cipher's bit-strength
+on an outbound SMTP connection; the meaning of
+this depends upon the TLS implementation used.
+If TLS has not been negotiated, the value will be 0.
+
+.vitem &$tls_in_ourcert$&
+.vindex "&$tls_in_ourcert$&"
+This variable refers to the certificate presented to the peer of an
+inbound connection when the message was received.
+It is only useful as the argument of a
+&%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator,
+or a &%def%& condition.
+
+.vitem &$tls_in_peercert$&
+.vindex "&$tls_in_peercert$&"
+This variable refers to the certificate presented by the peer of an
+inbound connection when the message was received.
+It is only useful as the argument of a
+&%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator,
+or a &%def%& condition.
+
+.vitem &$tls_out_ourcert$&
+.vindex "&$tls_out_ourcert$&"
+This variable refers to the certificate presented to the peer of an
+outbound connection.  It is only useful as the argument of a
+&%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator,
+or a &%def%& condition.
+
+.vitem &$tls_out_peercert$&
+.vindex "&$tls_out_peercert$&"
+This variable refers to the certificate presented by the peer of an
+outbound connection.  It is only useful as the argument of a
+&%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator,
+or a &%def%& condition.
+
+.vitem &$tls_in_certificate_verified$&
+.vindex "&$tls_in_certificate_verified$&"

 This variable is set to &"1"& if a TLS certificate was verified when the
 message was received, and &"0"& otherwise.
 
 This variable is set to &"1"& if a TLS certificate was verified when the
 message was received, and &"0"& otherwise.
 

-.vitem &$tls_cipher$&
+The deprecated &$tls_certificate_verfied$& variable refers to the inbound side
+except when used in the context of an outbound SMTP delivery, when it refers to
+the outbound.
+
+.vitem &$tls_out_certificate_verified$&
+.vindex "&$tls_out_certificate_verified$&"
+This variable is set to &"1"& if a TLS certificate was verified when an
+outbound SMTP connection was made,
+and &"0"& otherwise.
+
+.vitem &$tls_in_cipher$&
+.vindex "&$tls_in_cipher$&"

 .vindex "&$tls_cipher$&"
 When a message is received from a remote host over an encrypted SMTP
 connection, this variable is set to the cipher suite that was negotiated, for
 .vindex "&$tls_cipher$&"
 When a message is received from a remote host over an encrypted SMTP
 connection, this variable is set to the cipher suite that was negotiated, for


@@ -11798,21 +12491,77 @@ received over unencrypted connections, the variable is empty. Testing
 &$tls_cipher$& for emptiness is one way of distinguishing between encrypted and
 non-encrypted connections during ACL processing.
 
 &$tls_cipher$& for emptiness is one way of distinguishing between encrypted and
 non-encrypted connections during ACL processing.
 

-The &$tls_cipher$& variable retains its value during message delivery, except
-when an outward SMTP delivery takes place via the &(smtp)& transport. In this
-case, &$tls_cipher$& is cleared before any outgoing SMTP connection is made,
+The deprecated &$tls_cipher$& variable is the same as &$tls_in_cipher$& during message reception,
+but in the context of an outward SMTP delivery taking place via the &(smtp)& transport
+becomes the same as &$tls_out_cipher$&.
+
+.vitem &$tls_out_cipher$&
+.vindex "&$tls_out_cipher$&"
+This variable is
+cleared before any outgoing SMTP connection is made,

 and then set to the outgoing cipher suite if one is negotiated. See chapter
 &<<CHAPTLS>>& for details of TLS support and chapter &<<CHAPsmtptrans>>& for
 details of the &(smtp)& transport.
 
 and then set to the outgoing cipher suite if one is negotiated. See chapter
 &<<CHAPTLS>>& for details of TLS support and chapter &<<CHAPsmtptrans>>& for
 details of the &(smtp)& transport.
 

-.vitem &$tls_peerdn$&
+.vitem &$tls_in_ocsp$&
+.vindex "&$tls_in_ocsp$&"
+When a message is received from a remote client connection
+the result of any OCSP request from the client is encoded in this variable:
+.code
+0 OCSP proof was not requested (default value)
+1 No response to request
+2 Response not verified
+3 Verification failed
+4 Verification succeeded
+.endd
+
+.vitem &$tls_out_ocsp$&
+.vindex "&$tls_out_ocsp$&"
+When a message is sent to a remote host connection
+the result of any OCSP request made is encoded in this variable.
+See &$tls_in_ocsp$& for values.
+
+.vitem &$tls_in_peerdn$&
+.vindex "&$tls_in_peerdn$&"

 .vindex "&$tls_peerdn$&"
 When a message is received from a remote host over an encrypted SMTP
 connection, and Exim is configured to request a certificate from the client,
 the value of the Distinguished Name of the certificate is made available in the
 .vindex "&$tls_peerdn$&"
 When a message is received from a remote host over an encrypted SMTP
 connection, and Exim is configured to request a certificate from the client,
 the value of the Distinguished Name of the certificate is made available in the

-&$tls_peerdn$& during subsequent processing. Like &$tls_cipher$&, the
-value is retained during message delivery, except during outbound SMTP
-deliveries.
+&$tls_in_peerdn$& during subsequent processing.
+
+The deprecated &$tls_peerdn$& variable refers to the inbound side
+except when used in the context of an outbound SMTP delivery, when it refers to
+the outbound.
+
+.vitem &$tls_out_peerdn$&
+.vindex "&$tls_out_peerdn$&"
+When a message is being delivered to a remote host over an encrypted SMTP
+connection, and Exim is configured to request a certificate from the server,
+the value of the Distinguished Name of the certificate is made available in the
+&$tls_out_peerdn$& during subsequent processing.
+
+.vitem &$tls_in_sni$&
+.vindex "&$tls_in_sni$&"
+.vindex "&$tls_sni$&"
+.cindex "TLS" "Server Name Indication"
+When a TLS session is being established, if the client sends the Server
+Name Indication extension, the value will be placed in this variable.
+If the variable appears in &%tls_certificate%& then this option and
+some others, described in &<<SECTtlssni>>&,
+will be re-expanded early in the TLS session, to permit
+a different certificate to be presented (and optionally a different key to be
+used) to the client, based upon the value of the SNI extension.
+
+The deprecated &$tls_sni$& variable refers to the inbound side
+except when used in the context of an outbound SMTP delivery, when it refers to
+the outbound.
+
+.vitem &$tls_out_sni$&
+.vindex "&$tls_out_sni$&"
+.cindex "TLS" "Server Name Indication"
+During outbound
+SMTP deliveries, this variable reflects the value of the &%tls_sni%& option on
+the transport.

 
 .vitem &$tod_bsdinbox$&
 .vindex "&$tod_bsdinbox$&"
 
 .vitem &$tod_bsdinbox$&
 .vindex "&$tod_bsdinbox$&"


@@ -11823,6 +12572,10 @@ files, for example: Thu Oct 17 17:14:09 1995.
 .vindex "&$tod_epoch$&"
 The time and date as a number of seconds since the start of the Unix epoch.
 
 .vindex "&$tod_epoch$&"
 The time and date as a number of seconds since the start of the Unix epoch.
 

+.vitem &$tod_epoch_l$&
+.vindex "&$tod_epoch_l$&"
+The time and date as a number of microseconds since the start of the Unix epoch.
+

 .vitem &$tod_full$&
 .vindex "&$tod_full$&"
 A full version of the time and date, for example: Wed, 16 Oct 1995 09:51:40
 .vitem &$tod_full$&
 .vindex "&$tod_full$&"
 A full version of the time and date, for example: Wed, 16 Oct 1995 09:51:40


@@ -11851,12 +12604,25 @@ This variable contains the numerical value of the local timezone, for example:
 This variable contains the UTC date and time in &"Zulu"& format, as specified
 by ISO 8601, for example: 20030221154023Z.
 
 This variable contains the UTC date and time in &"Zulu"& format, as specified
 by ISO 8601, for example: 20030221154023Z.
 

+.vitem &$transport_name$&
+.cindex "transport" "name"
+.cindex "name" "of transport"
+.vindex "&$transport_name$&"
+During the running of a transport, this variable contains its name.
+

 .vitem &$value$&
 .vindex "&$value$&"
 This variable contains the result of an expansion lookup, extraction operation,
 or external command, as described above. It is also used during a
 &*reduce*& expansion.
 
 .vitem &$value$&
 .vindex "&$value$&"
 This variable contains the result of an expansion lookup, extraction operation,
 or external command, as described above. It is also used during a
 &*reduce*& expansion.
 

+.vitem &$verify_mode$&
+.vindex "&$verify_mode$&"
+While a router or transport is being run in verify mode
+or for cutthrough delivery,
+contains "S" for sender-verification or "R" for recipient-verification.
+Otherwise, empty.
+

 .vitem &$version_number$&
 .vindex "&$version_number$&"
 The version number of Exim.
 .vitem &$version_number$&
 .vindex "&$version_number$&"
 The version number of Exim.


@@ -12068,8 +12834,9 @@ option), the interfaces and ports on which it listens are controlled by the
 following options:
 
 .ilist
 following options:
 
 .ilist

-&%daemon_smtp_ports%& contains a list of default ports. (For backward
-compatibility, this option can also be specified in the singular.)
+&%daemon_smtp_ports%& contains a list of default ports
+or service names.
+(For backward compatibility, this option can also be specified in the singular.)

 .next
 &%local_interfaces%& contains list of interface IP addresses on which to
 listen. Each item may optionally also specify a port.
 .next
 &%local_interfaces%& contains list of interface IP addresses on which to
 listen. Each item may optionally also specify a port.


@@ -12170,7 +12937,8 @@ value of &%daemon_smtp_ports%& is no longer relevant in this example.)
 Exim supports the obsolete SSMTP protocol (also known as SMTPS) that was used
 before the STARTTLS command was standardized for SMTP. Some legacy clients
 still use this protocol. If the &%tls_on_connect_ports%& option is set to a
 Exim supports the obsolete SSMTP protocol (also known as SMTPS) that was used
 before the STARTTLS command was standardized for SMTP. Some legacy clients
 still use this protocol. If the &%tls_on_connect_ports%& option is set to a

-list of port numbers, connections to those ports must use SSMTP. The most
+list of port numbers or service names,
+connections to those ports must use SSMTP. The most

 common use of this option is expected to be
 .code
 tls_on_connect_ports = 465
 common use of this option is expected to be
 .code
 tls_on_connect_ports = 465


@@ -12262,7 +13030,7 @@ local_interfaces = 0.0.0.0 : 127.0.0.1.26
 .endd
 To specify listening on the default port on specific interfaces only:
 .code
 .endd
 To specify listening on the default port on specific interfaces only:
 .code

-local_interfaces = 192.168.34.67 : 192.168.34.67
+local_interfaces = 10.0.0.67 : 192.168.34.67

 .endd
 &*Warning*&: Such a setting excludes listening on the loopback interfaces.
 
 .endd
 &*Warning*&: Such a setting excludes listening on the loopback interfaces.
 


@@ -12506,6 +13274,7 @@ listed in more than one group.
 .row &%acl_smtp_auth%&               "ACL for AUTH"
 .row &%acl_smtp_connect%&            "ACL for connection"
 .row &%acl_smtp_data%&               "ACL for DATA"
 .row &%acl_smtp_auth%&               "ACL for AUTH"
 .row &%acl_smtp_connect%&            "ACL for connection"
 .row &%acl_smtp_data%&               "ACL for DATA"

+.row &%acl_smtp_data_prdr%&          "ACL for DATA, per-recipient"

 .row &%acl_smtp_dkim%&               "ACL for DKIM verification"
 .row &%acl_smtp_etrn%&               "ACL for ETRN"
 .row &%acl_smtp_expn%&               "ACL for EXPN"
 .row &%acl_smtp_dkim%&               "ACL for DKIM verification"
 .row &%acl_smtp_etrn%&               "ACL for ETRN"
 .row &%acl_smtp_expn%&               "ACL for EXPN"


@@ -12558,15 +13327,15 @@ listed in more than one group.
 
 .section "TLS" "SECID108"
 .table2
 
 .section "TLS" "SECID108"
 .table2

-.row &%gnutls_require_kx%&           "control GnuTLS key exchanges"
-.row &%gnutls_require_mac%&          "control GnuTLS MAC algorithms"
-.row &%gnutls_require_protocols%&    "control GnuTLS protocols"

 .row &%gnutls_compat_mode%&          "use GnuTLS compatibility mode"
 .row &%gnutls_compat_mode%&          "use GnuTLS compatibility mode"

+.row &%gnutls_allow_auto_pkcs11%&    "allow GnuTLS to autoload PKCS11 modules"

 .row &%openssl_options%&             "adjust OpenSSL compatibility options"
 .row &%tls_advertise_hosts%&         "advertise TLS to these hosts"
 .row &%tls_certificate%&             "location of server certificate"
 .row &%tls_crl%&                     "certificate revocation list"
 .row &%openssl_options%&             "adjust OpenSSL compatibility options"
 .row &%tls_advertise_hosts%&         "advertise TLS to these hosts"
 .row &%tls_certificate%&             "location of server certificate"
 .row &%tls_crl%&                     "certificate revocation list"

+.row &%tls_dh_max_bits%&             "clamp D-H bit count suggestion"

 .row &%tls_dhparam%&                 "DH parameters for server"
 .row &%tls_dhparam%&                 "DH parameters for server"

+.row &%tls_ocsp_file%&               "location of server certificate status proof"

 .row &%tls_on_connect_ports%&        "specify SSMTP (SMTPS) ports"
 .row &%tls_privatekey%&              "location of server private key"
 .row &%tls_remember_esmtp%&          "don't reset after starting TLS"
 .row &%tls_on_connect_ports%&        "specify SSMTP (SMTPS) ports"
 .row &%tls_privatekey%&              "location of server private key"
 .row &%tls_remember_esmtp%&          "don't reset after starting TLS"


@@ -12659,9 +13428,11 @@ See also the &'Policy controls'& section above.
 .table2
 .row &%accept_8bitmime%&             "advertise 8BITMIME"
 .row &%auth_advertise_hosts%&        "advertise AUTH to these hosts"
 .table2
 .row &%accept_8bitmime%&             "advertise 8BITMIME"
 .row &%auth_advertise_hosts%&        "advertise AUTH to these hosts"

+.row &%dsn_advertise_hosts%&         "advertise DSN extensions to these hosts"

 .row &%ignore_fromline_hosts%&       "allow &""From ""& from these hosts"
 .row &%ignore_fromline_local%&       "allow &""From ""& from local SMTP"
 .row &%pipelining_advertise_hosts%&  "advertise pipelining to these hosts"
 .row &%ignore_fromline_hosts%&       "allow &""From ""& from these hosts"
 .row &%ignore_fromline_local%&       "allow &""From ""& from local SMTP"
 .row &%pipelining_advertise_hosts%&  "advertise pipelining to these hosts"

+.row &%prdr_enable%&                 "advertise PRDR to all hosts"

 .row &%tls_advertise_hosts%&         "advertise TLS to these hosts"
 .endtable
 
 .row &%tls_advertise_hosts%&         "advertise TLS to these hosts"
 .endtable
 


@@ -12707,6 +13478,7 @@ See also the &'Policy controls'& section above.
 .row &%disable_ipv6%&                "do no IPv6 processing"
 .row &%dns_again_means_nonexist%&    "for broken domains"
 .row &%dns_check_names_pattern%&     "pre-DNS syntax check"
 .row &%disable_ipv6%&                "do no IPv6 processing"
 .row &%dns_again_means_nonexist%&    "for broken domains"
 .row &%dns_check_names_pattern%&     "pre-DNS syntax check"

+.row &%dns_dnssec_ok%&               "parameter for resolver"

 .row &%dns_ipv4_lookup%&             "only v4 lookup for these domains"
 .row &%dns_retrans%&                 "parameter for resolver"
 .row &%dns_retry%&                   "parameter for resolver"
 .row &%dns_ipv4_lookup%&             "only v4 lookup for these domains"
 .row &%dns_retrans%&                 "parameter for resolver"
 .row &%dns_retry%&                   "parameter for resolver"


@@ -12754,14 +13526,28 @@ See also the &'Policy controls'& section above.
 Those options that undergo string expansion before use are marked with
 &dagger;.
 
 Those options that undergo string expansion before use are marked with
 &dagger;.
 

-.option accept_8bitmime main boolean false
+.option accept_8bitmime main boolean true

 .cindex "8BITMIME"
 .cindex "8-bit characters"
 .cindex "8BITMIME"
 .cindex "8-bit characters"

+.cindex "log" "selectors"
+.cindex "log" "8BITMIME"

 This option causes Exim to send 8BITMIME in its response to an SMTP
 EHLO command, and to accept the BODY= parameter on MAIL commands.
 However, though Exim is 8-bit clean, it is not a protocol converter, and it
 takes no steps to do anything special with messages received by this route.
 This option causes Exim to send 8BITMIME in its response to an SMTP
 EHLO command, and to accept the BODY= parameter on MAIL commands.
 However, though Exim is 8-bit clean, it is not a protocol converter, and it
 takes no steps to do anything special with messages received by this route.

-Consequently, this option is turned off by default.
+
+Historically Exim kept this option off by default, but the maintainers
+feel that in today's Internet, this causes more problems than it solves.
+It now defaults to true.
+A more detailed analysis of the issues is provided by Dan Bernstein:
+.display
+&url(http://cr.yp.to/smtp/8bitmime.html)
+.endd
+
+To log received 8BITMIME status use
+.code
+log_selector = +8bitmime
+.endd

 
 .option acl_not_smtp main string&!! unset
 .cindex "&ACL;" "for non-SMTP messages"
 
 .option acl_not_smtp main string&!! unset
 .cindex "&ACL;" "for non-SMTP messages"


@@ -12798,6 +13584,19 @@ This option defines the ACL that is run after an SMTP DATA command has been
 processed and the message itself has been received, but before the final
 acknowledgment is sent. See chapter &<<CHAPACL>>& for further details.
 
 processed and the message itself has been received, but before the final
 acknowledgment is sent. See chapter &<<CHAPACL>>& for further details.
 

+.new
+.option acl_smtp_data_prdr main string&!! accept
+.cindex "PRDR" "ACL for"
+.cindex "DATA" "PRDR ACL for"
+.cindex "&ACL;" "PRDR-related"
+.cindex "&ACL;" "per-user data processing"
+.wen
+This option defines the ACL that,
+if the PRDR feature has been negotiated,
+is run for each recipient after an SMTP DATA command has been
+processed and the message itself has been received, but before the
+acknowledgment is sent. See chapter &<<CHAPACL>>& for further details.
+

 .option acl_smtp_etrn main string&!! unset
 .cindex "ETRN" "ACL for"
 This option defines the ACL that is run when an SMTP ETRN command is
 .option acl_smtp_etrn main string&!! unset
 .cindex "ETRN" "ACL for"
 This option defines the ACL that is run when an SMTP ETRN command is


@@ -12942,10 +13741,10 @@ If you want to advertise the availability of AUTH only when the connection
 is encrypted using TLS, you can make use of the fact that the value of this
 option is expanded, with a setting like this:
 .code
 is encrypted using TLS, you can make use of the fact that the value of this
 option is expanded, with a setting like this:
 .code

-auth_advertise_hosts = ${if eq{$tls_cipher}{}{}{*}}
+auth_advertise_hosts = ${if eq{$tls_in_cipher}{}{}{*}}

 .endd
 .endd

-.vindex "&$tls_cipher$&"
-If &$tls_cipher$& is empty, the session is not encrypted, and the result of
+.vindex "&$tls_in_cipher$&"
+If &$tls_in_cipher$& is empty, the session is not encrypted, and the result of

 the expansion is empty, thus matching no hosts. Otherwise, the result of the
 expansion is *, which matches all hosts.
 
 the expansion is empty, thus matching no hosts. Otherwise, the result of the
 expansion is *, which matches all hosts.
 


@@ -13192,6 +13991,9 @@ a very large time at the end of the list. For example:
 .code
 delay_warning = 2h:12h:99d
 .endd
 .code
 delay_warning = 2h:12h:99d
 .endd

+Note that the option is only evaluated at the time a delivery attempt fails,
+which depends on retry and queue-runner configuration.
+Typically retries will be configured more frequently than warning messages.

 
 .option delay_warning_condition main string&!! "see below"
 .vindex "&$domain$&"
 
 .option delay_warning_condition main string&!! "see below"
 .vindex "&$domain$&"


@@ -13313,6 +14115,17 @@ This option controls whether or not an IP address, given as a CSA domain, is
 reversed and looked up in the reverse DNS, as described in more detail in
 section &<<SECTverifyCSA>>&.
 
 reversed and looked up in the reverse DNS, as described in more detail in
 section &<<SECTverifyCSA>>&.
 

+
+.option dns_dnssec_ok main integer -1
+.cindex "DNS" "resolver options"
+.cindex "DNS" "DNSSEC"
+If this option is set to a non-negative number then Exim will initialise the
+DNS resolver library to either use or not use DNSSEC, overriding the system
+default. A value of 0 coerces DNSSEC off, a value of 1 coerces DNSSEC on.
+
+If the resolver library does not support DNSSEC then this option has no effect.
+
+

 .option dns_ipv4_lookup main "domain list&!!" unset
 .cindex "IPv6" "DNS lookup for AAAA records"
 .cindex "DNS" "IPv6 lookup for AAAA records"
 .option dns_ipv4_lookup main "domain list&!!" unset
 .cindex "IPv6" "DNS lookup for AAAA records"
 .cindex "DNS" "IPv6 lookup for AAAA records"


@@ -13343,7 +14156,6 @@ to set in them.
 See &%dns_retrans%& above.
 
 
 See &%dns_retrans%& above.
 
 

-.new

 .option dns_use_edns0 main integer -1
 .cindex "DNS" "resolver options"
 .cindex "DNS" "EDNS0"
 .option dns_use_edns0 main integer -1
 .cindex "DNS" "resolver options"
 .cindex "DNS" "EDNS0"


@@ -13353,7 +14165,6 @@ the system default. A value of 0 coerces EDNS0 off, a value of 1 coerces EDNS0
 on.
 
 If the resolver library does not support EDNS0 then this option has no effect.
 on.
 
 If the resolver library does not support EDNS0 then this option has no effect.

-.wen

 
 
 .option drop_cr main boolean false
 
 
 .option drop_cr main boolean false


@@ -13361,6 +14172,20 @@ This is an obsolete option that is now a no-op. It used to affect the way Exim
 handled CR and LF characters in incoming messages. What happens now is
 described in section &<<SECTlineendings>>&.
 
 handled CR and LF characters in incoming messages. What happens now is
 described in section &<<SECTlineendings>>&.
 

+.new
+.option dsn_advertise_hosts main "host list&!!" unset
+.cindex "bounce messages" "success"
+.cindex "DSN" "success"
+.cindex "Delivery Status Notification" "success"
+DSN extensions (RFC3461) will be advertised in the EHLO message to,
+and accepted from, these hosts.
+Hosts may use the NOTIFY and ENVID options on RCPT TO commands,
+and RET and ORCPT options on MAIL FROM commands.
+A NOTIFY=SUCCESS option requests success-DSN messages.
+A NOTIFY= option with no argument requests that no delay or failure DSNs
+are sent.
+.wen
+

 .option dsn_from main "string&!!" "see below"
 .cindex "&'From:'& header line" "in bounces"
 .cindex "bounce messages" "&'From:'& line, specifying"
 .option dsn_from main "string&!!" "see below"
 .cindex "&'From:'& header line" "in bounces"
 .cindex "bounce messages" "&'From:'& line, specifying"


@@ -13564,23 +14389,22 @@ gecos_name = $1
 See &%gecos_name%& above.
 
 
 See &%gecos_name%& above.
 
 

-.option gnutls_require_kx main string unset
-This option controls the key exchange mechanisms when GnuTLS is used in an Exim
-server. For details, see section &<<SECTreqciphgnu>>&.
-
-.option gnutls_require_mac main string unset
-This option controls the MAC algorithms when GnuTLS is used in an Exim
-server. For details, see section &<<SECTreqciphgnu>>&.
-
-.option gnutls_require_protocols main string unset
-This option controls the protocols when GnuTLS is used in an Exim
-server. For details, see section &<<SECTreqciphgnu>>&.
-

 .option gnutls_compat_mode main boolean unset
 This option controls whether GnuTLS is used in compatibility mode in an Exim
 server. This reduces security slightly, but improves interworking with older
 implementations of TLS.
 
 .option gnutls_compat_mode main boolean unset
 This option controls whether GnuTLS is used in compatibility mode in an Exim
 server. This reduces security slightly, but improves interworking with older
 implementations of TLS.
 

+
+option gnutls_allow_auto_pkcs11 main boolean unset
+This option will let GnuTLS (2.12.0 or later) autoload PKCS11 modules with
+the p11-kit configuration files in &_/etc/pkcs11/modules/_&.
+
+See
+&url(http://www.gnutls.org/manual/gnutls.html#Smart-cards-and-HSMs)
+for documentation.
+
+
+

 .option headers_charset main string "see below"
 This option sets a default character set for translating from encoded MIME
 &"words"& in header lines, when referenced by an &$h_xxx$& expansion item. The
 .option headers_charset main string "see below"
 This option sets a default character set for translating from encoded MIME
 &"words"& in header lines, when referenced by an &$h_xxx$& expansion item. The


@@ -14259,16 +15083,12 @@ harm. This option overrides the &%pipe_as_creator%& option of the &(pipe)&
 transport driver.
 
 
 transport driver.
 
 

-.option openssl_options main "string list" +dont_insert_empty_fragments
+.option openssl_options main "string list" "+no_sslv2"

 .cindex "OpenSSL "compatibility options"
 This option allows an administrator to adjust the SSL options applied
 by OpenSSL to connections.  It is given as a space-separated list of items,
 .cindex "OpenSSL "compatibility options"
 This option allows an administrator to adjust the SSL options applied
 by OpenSSL to connections.  It is given as a space-separated list of items,

-each one to be +added or -subtracted from the current value.  The default
-value is one option which happens to have been set historically.  You can
-remove all options with:
-.code
-openssl_options = -all
-.endd
+each one to be +added or -subtracted from the current value.
+

 This option is only available if Exim is built against OpenSSL.  The values
 available for this option vary according to the age of your OpenSSL install.
 The &"all"& value controls a subset of flags which are available, typically
 This option is only available if Exim is built against OpenSSL.  The values
 available for this option vary according to the age of your OpenSSL install.
 The &"all"& value controls a subset of flags which are available, typically


@@ -14280,14 +15100,90 @@ names lose the leading &"SSL_OP_"& and are lower-cased.
 Note that adjusting the options can have severe impact upon the security of
 SSL as used by Exim.  It is possible to disable safety checks and shoot
 yourself in the foot in various unpleasant ways.  This option should not be
 Note that adjusting the options can have severe impact upon the security of
 SSL as used by Exim.  It is possible to disable safety checks and shoot
 yourself in the foot in various unpleasant ways.  This option should not be

-adjusted lightly.  An unrecognised item will be detected at by invoking Exim
-with the &%-bV%& flag.
+adjusted lightly.  An unrecognised item will be detected at startup, by
+invoking Exim with the &%-bV%& flag.
+
+The option affects Exim operating both as a server and as a client.

 
 

-An example:
+Historical note: prior to release 4.80, Exim defaulted this value to
+"+dont_insert_empty_fragments", which may still be needed for compatibility
+with some clients, but which lowers security by increasing exposure to
+some now infamous attacks.
+
+Examples:

 .code
 .code

-openssl_options = -all +microsoft_big_sslv3_buffer
+# Make both old MS and old Eudora happy:
+openssl_options = -all +microsoft_big_sslv3_buffer \
+                       +dont_insert_empty_fragments
+
+# Disable older protocol versions:
+openssl_options = +no_sslv2 +no_sslv3

 .endd
 
 .endd
 

+Possible options may include:
+.ilist
+&`all`&
+.next
+&`allow_unsafe_legacy_renegotiation`&
+.next
+&`cipher_server_preference`&
+.next
+&`dont_insert_empty_fragments`&
+.next
+&`ephemeral_rsa`&
+.next
+&`legacy_server_connect`&
+.next
+&`microsoft_big_sslv3_buffer`&
+.next
+&`microsoft_sess_id_bug`&
+.next
+&`msie_sslv2_rsa_padding`&
+.next
+&`netscape_challenge_bug`&
+.next
+&`netscape_reuse_cipher_change_bug`&
+.next
+&`no_compression`&
+.next
+&`no_session_resumption_on_renegotiation`&
+.next
+&`no_sslv2`&
+.next
+&`no_sslv3`&
+.next
+&`no_ticket`&
+.next
+&`no_tlsv1`&
+.next
+&`no_tlsv1_1`&
+.next
+&`no_tlsv1_2`&
+.next
+&`safari_ecdhe_ecdsa_bug`&
+.next
+&`single_dh_use`&
+.next
+&`single_ecdh_use`&
+.next
+&`ssleay_080_client_dh_bug`&
+.next
+&`sslref2_reuse_cert_type_bug`&
+.next
+&`tls_block_padding_bug`&
+.next
+&`tls_d5_bug`&
+.next
+&`tls_rollback_bug`&
+.endlist
+
+As an aside, the &`safari_ecdhe_ecdsa_bug`& item is a misnomer and affects
+all clients connecting using the MacOS SecureTransport TLS facility prior
+to MacOS 10.8.4, including email clients.  If you see old MacOS clients failing
+to negotiate TLS then this option value might help, provided that your OpenSSL
+release is new enough to contain this work-around.  This may be a situation
+where you have to upgrade OpenSSL to get buggy clients working.
+

 
 .option oracle_servers main "string list" unset
 .cindex "Oracle" "server list"
 
 .option oracle_servers main "string list" unset
 .cindex "Oracle" "server list"


@@ -14362,6 +15258,15 @@ that clients will use it; &"out of order"& commands that are &"expected"& do
 not count as protocol errors (see &%smtp_max_synprot_errors%&).
 
 
 not count as protocol errors (see &%smtp_max_synprot_errors%&).
 
 

+.option prdr_enable main boolean false
+.cindex "PRDR" "enabling on server"
+This option can be used to enable the Per-Recipient Data Response extension
+to SMTP, defined by Eric Hall.
+If the option is set, PRDR is advertised by Exim when operating as a server.
+If the client requests PRDR, and more than one recipient, for a message 
+an additional ACL is called for each recipient after the message content
+is recieved.  See section &<<SECTPRDRACL>>&.
+

 .option preserve_message_logs main boolean false
 .cindex "message logs" "preserving"
 If this option is set, message log files are not deleted when messages are
 .option preserve_message_logs main boolean false
 .cindex "message logs" "preserving"
 If this option is set, message log files are not deleted when messages are


@@ -14614,7 +15519,7 @@ received_header_text = Received: \
   ${if def:sender_helo_name {(helo=$sender_helo_name)\n\t}}}}\
   by $primary_hostname \
   ${if def:received_protocol {with $received_protocol}} \
   ${if def:sender_helo_name {(helo=$sender_helo_name)\n\t}}}}\
   by $primary_hostname \
   ${if def:received_protocol {with $received_protocol}} \

-  ${if def:tls_cipher {($tls_cipher)\n\t}}\
+  ${if def:tls_in_cipher {($tls_in_cipher)\n\t}}\

   (Exim $version_number)\n\t\
   ${if def:sender_address \
   {(envelope-from <$sender_address>)\n\t}}\
   (Exim $version_number)\n\t\
   ${if def:sender_address \
   {(envelope-from <$sender_address>)\n\t}}\


@@ -14773,13 +15678,19 @@ the time of delivery. They are normally used only for final local deliveries.
 This option is an obsolete synonym for &%bounce_return_size_limit%&.
 
 
 This option is an obsolete synonym for &%bounce_return_size_limit%&.
 
 

-.option rfc1413_hosts main "host list&!!" *
+.new
+.option rfc1413_hosts main "host list&!!" @[]

 .cindex "RFC 1413"
 .cindex "host" "for RFC 1413 calls"
 .cindex "RFC 1413"
 .cindex "host" "for RFC 1413 calls"

-RFC 1413 identification calls are made to any client host which matches an item
-in the list.
+RFC 1413 identification calls are made to any client host which matches
+an item in the list.
+The default value specifies just this host, being any local interface
+for the system.
+.wen

 
 

-.option rfc1413_query_timeout main time 5s
+.new
+.option rfc1413_query_timeout main time 0s
+.wen

 .cindex "RFC 1413" "query timeout"
 .cindex "timeout" "for RFC 1413 call"
 This sets the timeout on RFC 1413 identification calls. If it is set to zero,
 .cindex "RFC 1413" "query timeout"
 .cindex "timeout" "for RFC 1413 call"
 This sets the timeout on RFC 1413 identification calls. If it is set to zero,


@@ -14857,8 +15768,15 @@ live with.
 
 . Allow this long option name to split; give it unsplit as a fifth argument
 . for the automatic .oindex that is generated by .option.
 
 . Allow this long option name to split; give it unsplit as a fifth argument
 . for the automatic .oindex that is generated by .option.

-
-.option "smtp_accept_max_per_ &~&~connection" main integer 1000 &&&
+. We insert " &~&~" which is both pretty nasty visually and results in
+. non-searchable text.  HowItWorks.txt mentions an option for inserting
+. zero-width-space, which would be nicer visually and results in (at least)
+. html that Firefox will split on when it's forced to reflow (rather than
+. inserting a horizontal scrollbar).  However, the text is still not
+. searchable.  NM changed this occurrence for bug 1197 to no longer allow
+. the option name to split.
+
+.option "smtp_accept_max_per_connection" main integer 1000 &&&

          smtp_accept_max_per_connection
 .cindex "SMTP" "limiting incoming message count"
 .cindex "limit" "messages per SMTP connection"
          smtp_accept_max_per_connection
 .cindex "SMTP" "limiting incoming message count"
 .cindex "limit" "messages per SMTP connection"


@@ -14908,10 +15826,9 @@ also &%queue_only%&, &%queue_only_load%&, &%queue_smtp_domains%&, and the
 various &%-od%&&'x'& command line options.
 
 
 various &%-od%&&'x'& command line options.
 
 

-. Allow this long option name to split; give it unsplit as a fifth argument
-. for the automatic .oindex that is generated by .option.
+. See the comment on smtp_accept_max_per_connection

 
 

-.option "smtp_accept_queue_per_ &~&~connection" main integer 10 &&&
+.option "smtp_accept_queue_per_connection" main integer 10 &&&

          smtp_accept_queue_per_connection
 .cindex "queueing incoming messages"
 .cindex "message" "queueing by message count"
          smtp_accept_queue_per_connection
 .cindex "queueing incoming messages"
 .cindex "message" "queueing by message count"


@@ -15167,7 +16084,7 @@ See &%smtp_ratelimit_hosts%& above.
 See &%smtp_ratelimit_hosts%& above.
 
 
 See &%smtp_ratelimit_hosts%& above.
 
 

-.option smtp_receive_timeout main time 5m
+.option smtp_receive_timeout main time&!! 5m

 .cindex "timeout" "for SMTP input"
 .cindex "SMTP" "input timeout"
 This sets a timeout value for SMTP reception. It applies to all forms of SMTP
 .cindex "timeout" "for SMTP input"
 .cindex "SMTP" "input timeout"
 This sets a timeout value for SMTP reception. It applies to all forms of SMTP


@@ -15182,6 +16099,10 @@ SMTP data timeout on connection from...
 The former means that Exim was expecting to read an SMTP command; the latter
 means that it was in the DATA phase, reading the contents of a message.
 
 The former means that Exim was expecting to read an SMTP command; the latter
 means that it was in the DATA phase, reading the contents of a message.
 

+If the first character of the option is a &"$"& the option is
+expanded before use and may depend on
+&$sender_host_name$&, &$sender_host_address$& and &$sender_host_port$&.
+

 
 .oindex "&%-os%&"
 The value set by this option can be overridden by the
 
 .oindex "&%-os%&"
 The value set by this option can be overridden by the


@@ -15477,6 +16398,10 @@ receiving incoming messages as a server. If you want to supply certificates for
 use when sending messages as a client, you must set the &%tls_certificate%&
 option in the relevant &(smtp)& transport.
 
 use when sending messages as a client, you must set the &%tls_certificate%&
 option in the relevant &(smtp)& transport.
 

+If the option contains &$tls_out_sni$& and Exim is built against OpenSSL, then
+if the OpenSSL build supports TLS extensions and the TLS client sends the
+Server Name Indication extension, then this option and others documented in
+&<<SECTtlssni>>& will be re-expanded.

 
 .option tls_crl main string&!! unset
 .cindex "TLS" "server certificate revocation list"
 
 .option tls_crl main string&!! unset
 .cindex "TLS" "server certificate revocation list"


@@ -15484,13 +16409,90 @@ option in the relevant &(smtp)& transport.
 This option specifies a certificate revocation list. The expanded value must
 be the name of a file that contains a CRL in PEM format.
 
 This option specifies a certificate revocation list. The expanded value must
 be the name of a file that contains a CRL in PEM format.
 

+See &<<SECTtlssni>>& for discussion of when this option might be re-expanded.
+
+
+.option tls_dh_max_bits main integer 2236
+.cindex "TLS" "D-H bit count"
+The number of bits used for Diffie-Hellman key-exchange may be suggested by
+the chosen TLS library.  That value might prove to be too high for
+interoperability.  This option provides a maximum clamp on the value
+suggested, trading off security for interoperability.
+
+The value must be at least 1024.
+
+The value 2236 was chosen because, at time of adding the option, it was the
+hard-coded maximum value supported by the NSS cryptographic library, as used
+by Thunderbird, while GnuTLS was suggesting 2432 bits as normal.
+
+If you prefer more security and are willing to break some clients, raise this
+number.
+
+Note that the value passed to GnuTLS for *generating* a new prime may be a
+little less than this figure, because GnuTLS is inexact and may produce a
+larger prime than requested.
+

 
 .option tls_dhparam main string&!! unset
 .cindex "TLS" "D-H parameters for server"
 
 .option tls_dhparam main string&!! unset
 .cindex "TLS" "D-H parameters for server"

-The value of this option is expanded, and must then be the absolute path to
-a file which contains the server's DH parameter values.
-This is used only for OpenSSL. When Exim is linked with GnuTLS, this option is
-ignored. See section &<<SECTopenvsgnu>>& for further details.
+The value of this option is expanded and indicates the source of DH parameters
+to be used by Exim.
+
+If it is a filename starting with a &`/`&, then it names a file from which DH
+parameters should be loaded.  If the file exists, it should hold a PEM-encoded
+PKCS#3 representation of the DH prime.  If the file does not exist, for
+OpenSSL it is an error.  For GnuTLS, Exim will attempt to create the file and
+fill it with a generated DH prime.  For OpenSSL, if the DH bit-count from
+loading the file is greater than &%tls_dh_max_bits%& then it will be ignored,
+and treated as though the &%tls_dhparam%& were set to "none".
+
+If this option expands to the string "none", then no DH parameters will be
+loaded by Exim.
+
+If this option expands to the string "historic" and Exim is using GnuTLS, then
+Exim will attempt to load a file from inside the spool directory.  If the file
+does not exist, Exim will attempt to create it.
+See section &<<SECTgnutlsparam>>& for further details.
+
+If Exim is using OpenSSL and this option is empty or unset, then Exim will load
+a default DH prime; the default is the 2048 bit prime described in section
+2.2 of RFC 5114, "2048-bit MODP Group with 224-bit Prime Order Subgroup", which
+in IKE is assigned number 23.
+
+Otherwise, the option must expand to the name used by Exim for any of a number
+of DH primes specified in RFC 2409, RFC 3526 and RFC 5114.  As names, Exim uses
+"ike" followed by the number used by IKE, of "default" which corresponds to
+"ike23".
+
+The available primes are:
+&`ike1`&, &`ike2`&, &`ike5`&,
+&`ike14`&, &`ike15`&, &`ike16`&, &`ike17`&, &`ike18`&,
+&`ike22`&, &`ike23`& (aka &`default`&) and &`ike24`&.
+
+Some of these will be too small to be accepted by clients.
+Some may be too large to be accepted by clients.
+
+The TLS protocol does not negotiate an acceptable size for this; clients tend
+to hard-drop connections if what is offered by the server is unacceptable,
+whether too large or too small, and there's no provision for the client to
+tell the server what these constraints are.  Thus, as a server operator, you
+need to make an educated guess as to what is most likely to work for your
+userbase.
+
+Some known size constraints suggest that a bit-size in the range 2048 to 2236
+is most likely to maximise interoperability.  The upper bound comes from
+applications using the Mozilla Network Security Services (NSS) library, which
+used to set its &`DH_MAX_P_BITS`& upper-bound to 2236.  This affects many
+mail user agents (MUAs). The lower bound comes from Debian installs of Exim4
+prior to the 4.80 release, as Debian used to patch Exim to raise the minimum
+acceptable bound from 1024 to 2048.
+
+
+.option tls_ocsp_file main string&!! unset
+This option
+must if set expand to the absolute path to a file which contains a current
+status proof for the server's certificate, as obtained from the
+Certificate Authority.

 
 
 .option tls_on_connect_ports main "string list" unset
 
 
 .option tls_on_connect_ports main "string list" unset


@@ -15509,6 +16511,8 @@ the expansion is forced to fail, or the result is an empty string, the private
 key is assumed to be in the same file as the server's certificates. See chapter
 &<<CHAPTLS>>& for further details.
 
 key is assumed to be in the same file as the server's certificates. See chapter
 &<<CHAPTLS>>& for further details.
 

+See &<<SECTtlssni>>& for discussion of when this option might be re-expanded.
+

 
 .option tls_remember_esmtp main boolean false
 .cindex "TLS" "esmtp state; remembering"
 
 .option tls_remember_esmtp main boolean false
 .cindex "TLS" "esmtp state; remembering"


@@ -15538,22 +16542,42 @@ preference order of the available ciphers. Details are given in sections
 See &%tls_verify_hosts%& below.
 
 
 See &%tls_verify_hosts%& below.
 
 

-.option tls_verify_certificates main string&!! unset
+.new
+.option tls_verify_certificates main string&!! system

 .cindex "TLS" "client certificate verification"
 .cindex "certificate" "verification of client"
 .cindex "TLS" "client certificate verification"
 .cindex "certificate" "verification of client"

-The value of this option is expanded, and must then be the absolute path to
-a file containing permitted certificates for clients that
-match &%tls_verify_hosts%& or &%tls_try_verify_hosts%&. Alternatively, if you
-are using OpenSSL, you can set &%tls_verify_certificates%& to the name of a
-directory containing certificate files. This does not work with GnuTLS; the
-option must be set to the name of a single file if you are using GnuTLS.
+The value of this option is expanded, and must then be either the
+word "system"
+or the absolute path to
+a file or directory containing permitted certificates for clients that
+match &%tls_verify_hosts%& or &%tls_try_verify_hosts%&.
+
+The "system" value for the option will use a
+system default location compiled into the SSL library.
+This is not available for GnuTLS versions preceding 3.0.20,
+and will be taken as empty; an explicit location
+must be specified.
+
+The use of a directory for the option value is not avilable for GnuTLS versions
+preceding 3.3.6 and a single file must be used.
+
+With OpenSSL the certificates specified
+explicitly
+either by file or directory
+are added to those given by the system default location.
+.wen

 
 These certificates should be for the certificate authorities trusted, rather
 than the public cert of individual clients.  With both OpenSSL and GnuTLS, if
 the value is a file then the certificates are sent by Exim as a server to
 connecting clients, defining the list of accepted certificate authorities.
 Thus the values defined should be considered public data.  To avoid this,
 
 These certificates should be for the certificate authorities trusted, rather
 than the public cert of individual clients.  With both OpenSSL and GnuTLS, if
 the value is a file then the certificates are sent by Exim as a server to
 connecting clients, defining the list of accepted certificate authorities.
 Thus the values defined should be considered public data.  To avoid this,

-use OpenSSL with a directory.
+use the explicit directory version.
+
+See &<<SECTtlssni>>& for discussion of when this option might be re-expanded.
+
+A forced expansion failure or setting to an empty string is equivalent to
+being unset.

 
 
 .option tls_verify_hosts main "host list&!!" unset
 
 
 .option tls_verify_hosts main "host list&!!" unset


@@ -15892,7 +16916,7 @@ router is skipped, and the address is offered to the next one.
 If the result is any other value, the router is run (as this is the last
 precondition to be evaluated, all the other preconditions must be true).
 
 If the result is any other value, the router is run (as this is the last
 precondition to be evaluated, all the other preconditions must be true).
 

-This option is unique in that multiple &%condition%& options may be present.
+This option is unusual in that multiple &%condition%& options may be present.

 All &%condition%& options must succeed.
 
 The &%condition%& option provides a means of applying custom conditions to the
 All &%condition%& options must succeed.
 
 The &%condition%& option provides a means of applying custom conditions to the


@@ -15917,11 +16941,52 @@ If the expansion fails (other than forced failure) delivery is deferred. Some
 of the other precondition options are common special cases that could in fact
 be specified using &%condition%&.
 
 of the other precondition options are common special cases that could in fact
 be specified using &%condition%&.
 

+Historical note: We have &%condition%& on ACLs and on Routers.  Routers
+are far older, and use one set of semantics.  ACLs are newer and when
+they were created, the ACL &%condition%& process was given far stricter
+parse semantics.  The &%bool{}%& expansion condition uses the same rules as
+ACLs.  The &%bool_lax{}%& expansion condition uses the same rules as
+Routers.  More pointedly, the &%bool_lax{}%& was written to match the existing
+Router rules processing behavior.
+
+This is best illustrated in an example:
+.code
+# If used in an ACL condition will fail with a syntax error, but
+# in a router condition any extra characters are treated as a string
+
+$ exim -be '${if eq {${lc:GOOGLE.com}} {google.com}} {yes} {no}}'
+true {yes} {no}}
+
+$ exim -be '${if eq {${lc:WHOIS.com}} {google.com}} {yes} {no}}'
+ {yes} {no}}
+.endd
+In each example above, the &%if%& statement actually ends after
+&"{google.com}}"&.  Since no true or false braces were defined, the
+default &%if%& behavior is to return a boolean true or a null answer
+(which evaluates to false). The rest of the line is then treated as a
+string. So the first example resulted in the boolean answer &"true"&
+with the string &" {yes} {no}}"& appended to it. The second example
+resulted in the null output (indicating false) with the string
+&" {yes} {no}}"& appended to it.
+
+In fact you can put excess forward braces in too.  In the router
+&%condition%&, Exim's parser only looks for &"{"& symbols when they
+mean something, like after a &"$"& or when required as part of a
+conditional.  But otherwise &"{"& and &"}"& are treated as ordinary
+string characters.
+
+Thus, in a Router, the above expansion strings will both always evaluate
+true, as the result of expansion is a non-empty string which doesn't
+match an explicit false value.  This can be tricky to debug.  By
+contrast, in an ACL either of those strings will always result in an
+expansion error because the result doesn't look sufficiently boolean.
+

 
 .option debug_print routers string&!! unset
 .cindex "testing" "variables in drivers"
 If this option is set and debugging is enabled (see the &%-d%& command line
 
 .option debug_print routers string&!! unset
 .cindex "testing" "variables in drivers"
 If this option is set and debugging is enabled (see the &%-d%& command line

-option), the string is expanded and included in the debugging output.
+option) or in address-testing mode (see the &%-bt%& command line option),
+the string is expanded and included in the debugging output.

 If expansion of the string fails, the error message is written to the debugging
 output, and Exim carries on processing.
 This option is provided to help with checking out the values of variables and
 If expansion of the string fails, the error message is written to the debugging
 output, and Exim carries on processing.
 This option is provided to help with checking out the values of variables and


@@ -15930,6 +16995,7 @@ option appears not to be working, &%debug_print%& can be used to output the
 variables it references. The output happens after checks for &%domains%&,
 &%local_parts%&, and &%check_local_user%& but before any other preconditions
 are tested. A newline is added to the text if it does not end with one.
 variables it references. The output happens after checks for &%domains%&,
 &%local_parts%&, and &%check_local_user%& but before any other preconditions
 are tested. A newline is added to the text if it does not end with one.

+The variable &$router_name$& contains the name of the router.

 
 
 
 
 
 


@@ -15956,6 +17022,17 @@ This option must always be set. It specifies which of the available routers is
 to be used.
 
 
 to be used.
 
 

+.new
+.option dsn_lasthop routers boolean false
+.cindex "DSN" "success"
+.cindex "Delivery Status Notification" "success"
+If this option is set true, and extended DSN (RFC3461) processing is in effect,
+Exim will not pass on DSN requests to downstream DSN-aware hosts but will
+instead send a success DSN as if the next hop does not support DSN.
+Not effective on redirect routers.
+.wen
+
+

 
 .option errors_to routers string&!! unset
 .cindex "envelope sender"
 
 .option errors_to routers string&!! unset
 .cindex "envelope sender"


@@ -16074,11 +17151,15 @@ and the discussion in chapter &<<CHAPenvironment>>&.
 
 
 
 
 
 

-.option headers_add routers string&!! unset
+.option headers_add routers list&!! unset

 .cindex "header lines" "adding"
 .cindex "router" "adding header lines"
 .cindex "header lines" "adding"
 .cindex "router" "adding header lines"

-This option specifies a string of text that is expanded at routing time, and
-associated with any addresses that are accepted by the router. However, this
+This option specifies a list of text headers,
+.new
+newline-separated (by default, changeable in the usual way),
+.wen
+that is associated with any addresses that are accepted by the router.
+Each item is separately expanded, at routing time.  However, this

 option has no effect when an address is just being verified. The way in which
 the text is used to add header lines at transport time is described in section
 &<<SECTheadersaddrem>>&. New header lines are not actually added until the
 option has no effect when an address is just being verified. The way in which
 the text is used to add header lines at transport time is described in section
 &<<SECTheadersaddrem>>&. New header lines are not actually added until the


@@ -16087,10 +17168,13 @@ header lines in string expansions in the transport's configuration do not
 &"see"& the added header lines.
 
 The &%headers_add%& option is expanded after &%errors_to%&, but before
 &"see"& the added header lines.
 
 The &%headers_add%& option is expanded after &%errors_to%&, but before

-&%headers_remove%& and &%transport%&. If the expanded string is empty, or if
-the expansion is forced to fail, the option has no effect. Other expansion
+&%headers_remove%& and &%transport%&. If an item is empty, or if
+an item expansion is forced to fail, the item has no effect. Other expansion

 failures are treated as configuration errors.
 
 failures are treated as configuration errors.
 

+Unlike most options, &%headers_add%& can be specified multiple times
+for a router; all listed headers are added.
+

 &*Warning 1*&: The &%headers_add%& option cannot be used for a &(redirect)&
 router that has the &%one_time%& option set.
 
 &*Warning 1*&: The &%headers_add%& option cannot be used for a &(redirect)&
 router that has the &%one_time%& option set.
 


@@ -16107,11 +17191,15 @@ avoided. The &%repeat_use%& option of the &%redirect%& router may be of help.
 
 
 
 
 
 

-.option headers_remove routers string&!! unset
+.option headers_remove routers list&!! unset

 .cindex "header lines" "removing"
 .cindex "router" "removing header lines"
 .cindex "header lines" "removing"
 .cindex "router" "removing header lines"

-This option specifies a string of text that is expanded at routing time, and
-associated with any addresses that are accepted by the router. However, this
+This option specifies a list of text headers,
+.new
+colon-separated (by default, changeable in the usual way),
+.wen
+that is associated with any addresses that are accepted by the router.
+Each item is separately expanded, at routing time.  However, this

 option has no effect when an address is just being verified. The way in which
 the text is used to remove header lines at transport time is described in
 section &<<SECTheadersaddrem>>&. Header lines are not actually removed until
 option has no effect when an address is just being verified. The way in which
 the text is used to remove header lines at transport time is described in
 section &<<SECTheadersaddrem>>&. Header lines are not actually removed until


@@ -16120,10 +17208,13 @@ to header lines in string expansions in the transport's configuration still
 &"see"& the original header lines.
 
 The &%headers_remove%& option is expanded after &%errors_to%& and
 &"see"& the original header lines.
 
 The &%headers_remove%& option is expanded after &%errors_to%& and

-&%headers_add%&, but before &%transport%&. If the expansion is forced to fail,
-the option has no effect. Other expansion failures are treated as configuration
+&%headers_add%&, but before &%transport%&. If an item expansion is forced to fail,
+the item has no effect. Other expansion failures are treated as configuration

 errors.
 
 errors.
 

+Unlike most options, &%headers_remove%& can be specified multiple times
+for a router; all listed headers are removed.
+

 &*Warning 1*&: The &%headers_remove%& option cannot be used for a &(redirect)&
 router that has the &%one_time%& option set.
 
 &*Warning 1*&: The &%headers_remove%& option cannot be used for a &(redirect)&
 router that has the &%one_time%& option set.
 


@@ -16760,7 +17851,8 @@ Setting this option has the effect of setting &%verify_sender%& and
 .cindex "EXPN" "with &%verify_only%&"
 .oindex "&%-bv%&"
 .cindex "router" "used only when verifying"
 .cindex "EXPN" "with &%verify_only%&"
 .oindex "&%-bv%&"
 .cindex "router" "used only when verifying"

-If this option is set, the router is used only when verifying an address or
+If this option is set, the router is used only when verifying an address,
+delivering in cutthrough mode or

 testing with the &%-bv%& option, not when actually doing a delivery, testing
 with the &%-bt%& option, or running the SMTP EXPN command. It can be further
 restricted to verifying only senders or recipients by means of
 testing with the &%-bv%& option, not when actually doing a delivery, testing
 with the &%-bt%& option, or running the SMTP EXPN command. It can be further
 restricted to verifying only senders or recipients by means of


@@ -16774,10 +17866,12 @@ user or group.
 
 .option verify_recipient routers&!? boolean true
 If this option is false, the router is skipped when verifying recipient
 
 .option verify_recipient routers&!? boolean true
 If this option is false, the router is skipped when verifying recipient

-addresses
+addresses,
+delivering in cutthrough mode

 or testing recipient verification using &%-bv%&.
 See section &<<SECTrouprecon>>& for a list of the order in which preconditions
 are evaluated.
 or testing recipient verification using &%-bv%&.
 See section &<<SECTrouprecon>>& for a list of the order in which preconditions
 are evaluated.

+See also the &$verify_mode$& variable.

 
 
 .option verify_sender routers&!? boolean true
 
 
 .option verify_sender routers&!? boolean true


@@ -16785,6 +17879,7 @@ If this option is false, the router is skipped when verifying sender addresses
 or testing sender verification using &%-bvs%&.
 See section &<<SECTrouprecon>>& for a list of the order in which preconditions
 are evaluated.
 or testing sender verification using &%-bvs%&.
 See section &<<SECTrouprecon>>& for a list of the order in which preconditions
 are evaluated.

+See also the &$verify_mode$& variable.

 .ecindex IIDgenoprou1
 .ecindex IIDgenoprou2
 
 .ecindex IIDgenoprou1
 .ecindex IIDgenoprou2
 


@@ -16875,6 +17970,38 @@ look for A or AAAA records, unless the domain matches &%mx_domains%&, in which
 case routing fails.
 
 
 case routing fails.
 
 

+.section "Declining addresses by dnslookup" "SECTdnslookupdecline"
+.cindex "&(dnslookup)& router" "declines"
+There are a few cases where a &(dnslookup)& router will decline to accept
+an address; if such a router is expected to handle "all remaining non-local
+domains", then it is important to set &%no_more%&.
+
+Reasons for a &(dnslookup)& router to decline currently include:
+.ilist
+The domain does not exist in DNS
+.next
+The domain exists but the MX record's host part is just "."; this is a common
+convention (borrowed from SRV) used to indicate that there is no such service
+for this domain and to not fall back to trying A/AAAA records.
+.next
+Ditto, but for SRV records, when &%check_srv%& is set on this router.
+.next
+MX record points to a non-existent host.
+.next
+MX record points to an IP address and the main section option
+&%allow_mx_to_ip%& is not set.
+.next
+MX records exist and point to valid hosts, but all hosts resolve only to
+addresses blocked by the &%ignore_target_hosts%& generic option on this router.
+.next
+The domain is not syntactically valid (see also &%allow_utf8_domains%& and
+&%dns_check_names_pattern%& for handling one variant of this)
+.next
+&%check_secondary_mx%& is set on this router but the local host can
+not be found in the MX records (see below)
+.endlist
+
+

 
 
 .section "Private options for dnslookup" "SECID118"
 
 
 .section "Private options for dnslookup" "SECID118"


@@ -16927,6 +18054,29 @@ when there is a DNS lookup error.
 
 
 
 
 
 

+.option dnssec_request_domains dnslookup "domain list&!!" unset
+.cindex "MX record" "security"
+.cindex "DNSSEC" "MX lookup"
+.cindex "security" "MX lookup"
+.cindex "DNS" "DNSSEC"
+DNS lookups for domains matching &%dnssec_request_domains%& will be done with
+the dnssec request bit set.
+This applies to all of the SRV, MX A6, AAAA, A lookup sequence.
+
+
+
+.option dnssec_require_domains dnslookup "domain list&!!" unset
+.cindex "MX record" "security"
+.cindex "DNSSEC" "MX lookup"
+.cindex "security" "MX lookup"
+.cindex "DNS" "DNSSEC"
+DNS lookups for domains matching &%dnssec_request_domains%& will be done with
+the dnssec request bit set.  Any returns not having the Authenticated Data bit
+(AD bit) set wil be ignored and logged as a host-lookup failure.
+This applies to all of the SRV, MX A6, AAAA, A lookup sequence.
+
+
+

 .option mx_domains dnslookup "domain list&!!" unset
 .cindex "MX record" "required to exist"
 .cindex "SRV record" "required to exist"
 .option mx_domains dnslookup "domain list&!!" unset
 .cindex "MX record" "required to exist"
 .cindex "SRV record" "required to exist"


@@ -17895,6 +19045,13 @@ However, there are some private options which define transports for delivery to
 files and pipes, and for generating autoreplies. See the &%file_transport%&,
 &%pipe_transport%& and &%reply_transport%& descriptions below.
 
 files and pipes, and for generating autoreplies. See the &%file_transport%&,
 &%pipe_transport%& and &%reply_transport%& descriptions below.
 

+.new
+If success DSNs have been requested
+.cindex "DSN" "success"
+.cindex "Delivery Status Notification" "success"
+redirection triggers one and the DSN options are not passed any further.
+.wen
+

 
 
 .section "Redirection data" "SECID124"
 
 
 .section "Redirection data" "SECID124"


@@ -18098,6 +19255,16 @@ quote just the command. An item such as
 .endd
 is interpreted as a pipe with a rather strange command name, and no arguments.
 
 .endd
 is interpreted as a pipe with a rather strange command name, and no arguments.
 

+Note that the above example assumes that the text comes from a lookup source
+of some sort, so that the quotes are part of the data.  If composing a
+redirect router with a &%data%& option directly specifying this command, the
+quotes will be used by the configuration parser to define the extent of one
+string, but will not be passed down into the redirect router itself.  There
+are two main approaches to get around this: escape quotes to be part of the
+data itself, or avoid using this mechanism and instead create a custom
+transport with the &%command%& option set and reference that transport from
+an &%accept%& router.
+

 .next
 .cindex "file" "in redirection list"
 .cindex "address redirection" "to file"
 .next
 .cindex "file" "in redirection list"
 .cindex "address redirection" "to file"


@@ -19038,7 +20205,8 @@ so on when debugging driver configurations. For example, if a &%headers_add%&
 option is not working properly, &%debug_print%& could be used to output the
 variables it references. A newline is added to the text if it does not end with
 one.
 option is not working properly, &%debug_print%& could be used to output the
 variables it references. A newline is added to the text if it does not end with
 one.

-
+The variables &$transport_name$& and &$router_name$& contain the name of the
+transport and the router that called it.

 
 .option delivery_date_add transports boolean false
 .cindex "&'Delivery-date:'& header line"
 
 .option delivery_date_add transports boolean false
 .cindex "&'Delivery-date:'& header line"


@@ -19073,16 +20241,22 @@ value that the router supplies, and also overriding any value associated with
 &%user%& (see below).
 
 
 &%user%& (see below).
 
 

-.option headers_add transports string&!! unset
+.option headers_add transports list&!! unset

 .cindex "header lines" "adding in transport"
 .cindex "transport" "header lines; adding"
 .cindex "header lines" "adding in transport"
 .cindex "transport" "header lines; adding"

-This option specifies a string of text that is expanded and added to the header
+This option specifies a list of text headers,
+.new
+newline-separated (by default, changeable in the usual way),
+.wen
+which are (separately) expanded and added to the header

 portion of a message as it is transported, as described in section
 &<<SECTheadersaddrem>>&. Additional header lines can also be specified by
 routers. If the result of the expansion is an empty string, or if the expansion
 is forced to fail, no action is taken. Other expansion failures are treated as
 errors and cause the delivery to be deferred.
 
 portion of a message as it is transported, as described in section
 &<<SECTheadersaddrem>>&. Additional header lines can also be specified by
 routers. If the result of the expansion is an empty string, or if the expansion
 is forced to fail, no action is taken. Other expansion failures are treated as
 errors and cause the delivery to be deferred.
 

+Unlike most options, &%headers_add%& can be specified multiple times
+for a transport; all listed headers are added.

 
 
 .option headers_only transports boolean false
 
 
 .option headers_only transports boolean false


@@ -19095,16 +20269,24 @@ transports, the settings of &%message_prefix%& and &%message_suffix%& should be
 checked, since this option does not automatically suppress them.
 
 
 checked, since this option does not automatically suppress them.
 
 

-.option headers_remove transports string&!! unset
+.option headers_remove transports list&!! unset

 .cindex "header lines" "removing"
 .cindex "transport" "header lines; removing"
 .cindex "header lines" "removing"
 .cindex "transport" "header lines; removing"

-This option specifies a string that is expanded into a list of header names;
+This option specifies a list of header names,
+.new
+colon-separated (by default, changeable in the usual way);
+.wen

 these headers are omitted from the message as it is transported, as described
 in section &<<SECTheadersaddrem>>&. Header removal can also be specified by
 these headers are omitted from the message as it is transported, as described
 in section &<<SECTheadersaddrem>>&. Header removal can also be specified by

-routers. If the result of the expansion is an empty string, or if the expansion
+routers.
+Each list item is separately expanded.
+If the result of the expansion is an empty string, or if the expansion

 is forced to fail, no action is taken. Other expansion failures are treated as
 errors and cause the delivery to be deferred.
 
 is forced to fail, no action is taken. Other expansion failures are treated as
 errors and cause the delivery to be deferred.
 

+Unlike most options, &%headers_remove%& can be specified multiple times
+for a router; all listed headers are removed.
+

 
 
 .option headers_rewrite transports string unset
 
 
 .option headers_rewrite transports string unset


@@ -19409,7 +20591,7 @@ message, which happens if the &%return_message%& option is set.
 
 .option transport_filter_timeout transports time 5m
 .cindex "transport" "filter, timeout"
 
 .option transport_filter_timeout transports time 5m
 .cindex "transport" "filter, timeout"

-When Exim is reading the output of a transport filter, it a applies a timeout
+When Exim is reading the output of a transport filter, it applies a timeout

 that can be set by this option. Exceeding the timeout is normally treated as a
 temporary delivery failure. However, if a transport filter is used with a
 &(pipe)& transport, a timeout in the transport filter is treated in the same
 that can be set by this option. Exceeding the timeout is normally treated as a
 temporary delivery failure. However, if a transport filter is used with a
 &(pipe)& transport, a timeout in the transport filter is treated in the same


@@ -19993,7 +21175,6 @@ This option applies only to deliveries in maildir format, and is described in
 section &<<SECTmaildirdelivery>>& below.
 
 
 section &<<SECTmaildirdelivery>>& below.
 
 

-.new

 .option maildir_use_size_file appendfile&!! boolean false
 .cindex "maildir format" "&_maildirsize_& file"
 The result of string expansion for this option must be a valid boolean value.
 .option maildir_use_size_file appendfile&!! boolean false
 .cindex "maildir format" "&_maildirsize_& file"
 The result of string expansion for this option must be a valid boolean value.


@@ -20002,7 +21183,6 @@ creates a &_maildirsize_& file in a maildir if one does not exist, taking the
 quota from the &%quota%& option of the transport. If &%quota%& is unset, the
 value is zero. See &%maildir_quota_directory_regex%& above and section
 &<<SECTmaildirdelivery>>& below for further details.
 quota from the &%quota%& option of the transport. If &%quota%& is unset, the
 value is zero. See &%maildir_quota_directory_regex%& above and section
 &<<SECTmaildirdelivery>>& below for further details.

-.wen

 
 .option maildirfolder_create_regex appendfile string unset
 .cindex "maildir format" "&_maildirfolder_& file"
 
 .option maildirfolder_create_regex appendfile string unset
 .cindex "maildir format" "&_maildirfolder_& file"


@@ -21027,10 +22207,10 @@ that are routed to the transport.
 .vindex "&$address_pipe$&"
 A router redirects an address directly to a pipe command (for example, from an
 alias or forward file). In this case, &$address_pipe$& contains the text of the
 .vindex "&$address_pipe$&"
 A router redirects an address directly to a pipe command (for example, from an
 alias or forward file). In this case, &$address_pipe$& contains the text of the

-pipe command, and the &%command%& option on the transport is ignored. If only
-one address is being transported (&%batch_max%& is not greater than one, or
-only one address was redirected to this pipe command), &$local_part$& contains
-the local part that was redirected.
+pipe command, and the &%command%& option on the transport is ignored unless
+&%force_command%& is set. If only one address is being transported
+(&%batch_max%& is not greater than one, or only one address was redirected to
+this pipe command), &$local_part$& contains the local part that was redirected.

 .endlist
 
 
 .endlist
 
 


@@ -21138,6 +22318,15 @@ inserted in the argument list at that point &'as a separate argument'&. This
 avoids any problems with spaces or shell metacharacters, and is of use when a
 &(pipe)& transport is handling groups of addresses in a batch.
 
 avoids any problems with spaces or shell metacharacters, and is of use when a
 &(pipe)& transport is handling groups of addresses in a batch.
 

+If &%force_command%& is enabled on the transport, Special handling takes place
+for an argument that consists of precisely the text &`$address_pipe`&.  It
+is handled similarly to &$pipe_addresses$& above.  It is expanded and each
+argument is inserted in the argument list at that point
+&'as a separate argument'&.  The &`$address_pipe`& item does not need to be
+the only item in the argument; in fact, if it were then &%force_command%&
+should behave as a no-op.  Rather, it should be used to adjust the command
+run while preserving the argument vector separation.
+

 After splitting up into arguments and expansion, the resulting command is run
 in a subprocess directly from the transport, &'not'& under a shell. The
 message that is being delivered is supplied on the standard input, and the
 After splitting up into arguments and expansion, the resulting command is run
 in a subprocess directly from the transport, &'not'& under a shell. The
 message that is being delivered is supplied on the standard input, and the


@@ -21290,6 +22479,23 @@ a bounce message is sent. If &%freeze_signal%& is set, the message will be
 frozen in Exim's queue instead.
 
 
 frozen in Exim's queue instead.
 
 

+.option force_command pipe boolean false
+.cindex "force command"
+.cindex "&(pipe)& transport", "force command"
+Normally when a router redirects an address directly to a pipe command
+the &%command%& option on the transport is ignored.  If &%force_command%&
+is set, the &%command%& option will used. This is especially
+useful for forcing a wrapper or additional argument to be added to the
+command. For example:
+.code
+command = /usr/bin/remote_exec myhost -- $address_pipe
+force_command
+.endd
+
+Note that &$address_pipe$& is handled specially in &%command%& when
+&%force_command%& is set, expanding out to the original argument vector as
+separate items, similarly to a Unix shell &`"$@"`& construct.
+

 .option ignore_status pipe boolean false
 If this option is true, the status returned by the subprocess that is set up to
 run the command is ignored, and Exim behaves as if zero had been returned.
 .option ignore_status pipe boolean false
 If this option is true, the status returned by the subprocess that is set up to
 run the command is ignored, and Exim behaves as if zero had been returned.


@@ -21637,17 +22843,23 @@ that are in force when the &%helo_data%&, &%hosts_try_auth%&, &%interface%&,
 
 
 .section "Use of $tls_cipher and $tls_peerdn" "usecippeer"
 
 
 .section "Use of $tls_cipher and $tls_peerdn" "usecippeer"

+.vindex &$tls_bits$&

 .vindex &$tls_cipher$&
 .vindex &$tls_peerdn$&
 .vindex &$tls_cipher$&
 .vindex &$tls_peerdn$&

-At the start of a run of the &(smtp)& transport, the values of &$tls_cipher$&
-and &$tls_peerdn$& are the values that were set when the message was received.
+.vindex &$tls_sni$&
+At the start of a run of the &(smtp)& transport, the values of &$tls_bits$&,
+&$tls_cipher$&, &$tls_peerdn$& and &$tls_sni$&
+are the values that were set when the message was received.

 These are the values that are used for options that are expanded before any
 These are the values that are used for options that are expanded before any

-SMTP connections are made. Just before each connection is made, these two
+SMTP connections are made. Just before each connection is made, these four

 variables are emptied. If TLS is subsequently started, they are set to the
 appropriate values for the outgoing connection, and these are the values that
 are in force when any authenticators are run and when the
 &%authenticated_sender%& option is expanded.
 
 variables are emptied. If TLS is subsequently started, they are set to the
 appropriate values for the outgoing connection, and these are the values that
 are in force when any authenticators are run and when the
 &%authenticated_sender%& option is expanded.
 

+These variables are deprecated in favour of &$tls_in_cipher$& et. al.
+and will be removed in a future release.
+

 
 .section "Private options for smtp" "SECID146"
 .cindex "options" "&(smtp)& transport"
 
 .section "Private options for smtp" "SECID146"
 .cindex "options" "&(smtp)& transport"


@@ -21685,7 +22897,7 @@ ignored.
 
 The expansion happens after the outgoing connection has been made and TLS
 started, if required. This means that the &$host$&, &$host_address$&,
 
 The expansion happens after the outgoing connection has been made and TLS
 started, if required. This means that the &$host$&, &$host_address$&,

-&$tls_cipher$&, and &$tls_peerdn$& variables are set according to the
+&$tls_out_cipher$&, and &$tls_out_peerdn$& variables are set according to the

 particular connection.
 
 If the SMTP session is not authenticated, the expansion of
 particular connection.
 
 If the SMTP session is not authenticated, the expansion of


@@ -21781,6 +22993,43 @@ See the &%search_parents%& option in chapter &<<CHAPdnslookup>>& for more
 details.
 
 
 details.
 
 

+.option dnssec_request_domains smtp "domain list&!!" unset
+.cindex "MX record" "security"
+.cindex "DNSSEC" "MX lookup"
+.cindex "security" "MX lookup"
+.cindex "DNS" "DNSSEC"
+DNS lookups for domains matching &%dnssec_request_domains%& will be done with
+the dnssec request bit set.
+This applies to all of the SRV, MX A6, AAAA, A lookup sequence.
+
+
+
+.option dnssec_require_domains smtp "domain list&!!" unset
+.cindex "MX record" "security"
+.cindex "DNSSEC" "MX lookup"
+.cindex "security" "MX lookup"
+.cindex "DNS" "DNSSEC"
+DNS lookups for domains matching &%dnssec_request_domains%& will be done with
+the dnssec request bit set.  Any returns not having the Authenticated Data bit
+(AD bit) set wil be ignored and logged as a host-lookup failure.
+This applies to all of the SRV, MX A6, AAAA, A lookup sequence.
+
+
+
+.option dscp smtp string&!! unset
+.cindex "DCSP" "outbound"
+This option causes the DSCP value associated with a socket to be set to one
+of a number of fixed strings or to numeric value.
+The &%-bI:dscp%& option may be used to ask Exim which names it knows of.
+Common values include &`throughput`&, &`mincost`&, and on newer systems
+&`ef`&, &`af41`&, etc.  Numeric values may be in the range 0 to 0x3F.
+
+The outbound packets from Exim will be marked with this value in the header
+(for IPv4, the TOS field; for IPv6, the TCLASS field); there is no guarantee
+that these values will have any effect, not be stripped by networking
+equipment, or do much of anything without cooperation with your Network
+Engineer and those of all network operators between the source and destination.
+

 
 .option fallback_hosts smtp "string list" unset
 .cindex "fallback" "hosts specified on transport"
 
 .option fallback_hosts smtp "string list" unset
 .cindex "fallback" "hosts specified on transport"


@@ -21828,18 +23077,6 @@ being used, names are looked up using &[gethostbyname()]&
 instead of using the DNS. Of course, that function may in fact use the DNS, but
 it may also consult other sources of information such as &_/etc/hosts_&.
 
 instead of using the DNS. Of course, that function may in fact use the DNS, but
 it may also consult other sources of information such as &_/etc/hosts_&.
 

-.option gnutls_require_kx smtp string unset
-This option controls the key exchange mechanisms when GnuTLS is used in an Exim
-client. For details, see section &<<SECTreqciphgnu>>&.
-
-.option gnutls_require_mac smtp string unset
-This option controls the MAC algorithms when GnuTLS is used in an Exim
-client. For details, see section &<<SECTreqciphgnu>>&.
-
-.option gnutls_require_protocols smtp string unset
-This option controls the protocols when GnuTLS is used in an Exim
-client. For details, see section &<<SECTreqciphgnu>>&.
-

 .option gnutls_compat_mode smtp boolean unset
 This option controls whether GnuTLS is used in compatibility mode in an Exim
 server. This reduces security slightly, but improves interworking with older
 .option gnutls_compat_mode smtp boolean unset
 This option controls whether GnuTLS is used in compatibility mode in an Exim
 server. This reduces security slightly, but improves interworking with older


@@ -21926,6 +23163,13 @@ that matches this list, even if the server host advertises PIPELINING support.
 Exim will not try to start a TLS session when delivering to any host that
 matches this list. See chapter &<<CHAPTLS>>& for details of TLS.
 
 Exim will not try to start a TLS session when delivering to any host that
 matches this list. See chapter &<<CHAPTLS>>& for details of TLS.
 

+.option hosts_verify_avoid_tls smtp "host list&!!" *
+.cindex "TLS" "avoiding for certain hosts"
+Exim will not try to start a TLS session for a verify callout,
+or when delivering in cutthrough mode,
+to any host that matches this list.
+Note that the default is to not use TLS.
+

 
 .option hosts_max_try smtp integer 5
 .cindex "host" "maximum number to try"
 
 .option hosts_max_try smtp integer 5
 .cindex "host" "maximum number to try"


@@ -21994,6 +23238,18 @@ hard failure if required. See also &%hosts_try_auth%&, and chapter
 &<<CHAPSMTPAUTH>>& for details of authentication.
 
 
 &<<CHAPSMTPAUTH>>& for details of authentication.
 
 

+.option hosts_request_ocsp smtp "host list&!!" *
+.cindex "TLS" "requiring for certain servers"
+Exim will request a Certificate Status on a
+TLS session for any host that matches this list.
+&%tls_verify_certificates%& should also be set for the transport.
+
+.option hosts_require_ocsp smtp "host list&!!" unset
+.cindex "TLS" "requiring for certain servers"
+Exim will request, and check for a valid Certificate Status being given, on a
+TLS session for any host that matches this list.
+&%tls_verify_certificates%& should also be set for the transport.
+

 .option hosts_require_tls smtp "host list&!!" unset
 .cindex "TLS" "requiring for certain servers"
 Exim will insist on using a TLS session when delivering to any host that
 .option hosts_require_tls smtp "host list&!!" unset
 .cindex "TLS" "requiring for certain servers"
 Exim will insist on using a TLS session when delivering to any host that


@@ -22009,6 +23265,15 @@ connects. If authentication fails, Exim will try to transfer the message
 unauthenticated. See also &%hosts_require_auth%&, and chapter
 &<<CHAPSMTPAUTH>>& for details of authentication.
 
 unauthenticated. See also &%hosts_require_auth%&, and chapter
 &<<CHAPSMTPAUTH>>& for details of authentication.
 

+.new
+.option hosts_try_prdr smtp "host list&!!" *
+.cindex "PRDR" "enabling, optional in client"
+This option provides a list of servers to which, provided they announce
+PRDR support, Exim will attempt to negotiate PRDR
+for multi-recipient messages.
+The option can usually be left as default.
+.wen
+

 .option interface smtp "string list&!!" unset
 .cindex "bind IP address"
 .cindex "IP address" "binding"
 .option interface smtp "string list&!!" unset
 .cindex "bind IP address"
 .cindex "IP address" "binding"


@@ -22065,7 +23330,7 @@ so can cause parallel connections to the same host if &%remote_max_parallel%&
 permits this.
 
 
 permits this.
 
 

-.option multi_domain smtp boolean true
+.option multi_domain smtp boolean&!! true

 .vindex "&$domain$&"
 When this option is set, the &(smtp)& transport can handle a number of
 addresses containing a mixture of different domains provided they all resolve
 .vindex "&$domain$&"
 When this option is set, the &(smtp)& transport can handle a number of
 addresses containing a mixture of different domains provided they all resolve


@@ -22074,6 +23339,11 @@ handling only one domain at a time. This is useful if you want to use
 &$domain$& in an expansion for the transport, because it is set only when there
 is a single domain involved in a remote delivery.
 
 &$domain$& in an expansion for the transport, because it is set only when there
 is a single domain involved in a remote delivery.
 

+.new
+It is expanded per-address and can depend on any of
+&$address_data$&, &$domain_data$&, &$local_part_data$&,
+&$host$&, &$host_address$& and &$host_port$&.
+.wen

 
 .option port smtp string&!! "see below"
 .cindex "port" "sending TCP/IP"
 
 .option port smtp string&!! "see below"
 .cindex "port" "sending TCP/IP"


@@ -22103,15 +23373,13 @@ protocol (RFC 2033) instead of SMTP. This protocol is sometimes used for local
 deliveries into closed message stores. Exim also has support for running LMTP
 over a pipe to a local process &-- see chapter &<<CHAPLMTP>>&.
 
 deliveries into closed message stores. Exim also has support for running LMTP
 over a pipe to a local process &-- see chapter &<<CHAPLMTP>>&.
 

-.new

 If this option is set to &"smtps"&, the default vaule for the &%port%& option
 changes to &"smtps"&, and the transport initiates TLS immediately after
 connecting, as an outbound SSL-on-connect, instead of using STARTTLS to upgrade.
 The Internet standards bodies strongly discourage use of this mode.
 If this option is set to &"smtps"&, the default vaule for the &%port%& option
 changes to &"smtps"&, and the transport initiates TLS immediately after
 connecting, as an outbound SSL-on-connect, instead of using STARTTLS to upgrade.
 The Internet standards bodies strongly discourage use of this mode.

-.wen

 
 
 
 

-.option retry_include_ip_address smtp boolean true
+.option retry_include_ip_address smtp boolean&!! true

 Exim normally includes both the host name and the IP address in the key it
 constructs for indexing retry data after a temporary delivery failure. This
 means that when one of several IP addresses for a host is failing, it gets
 Exim normally includes both the host name and the IP address in the key it
 constructs for indexing retry data after a temporary delivery failure. This
 means that when one of several IP addresses for a host is failing, it gets


@@ -22121,9 +23389,10 @@ addresses is not affected.
 However, in some dialup environments hosts are assigned a different IP address
 each time they connect. In this situation the use of the IP address as part of
 the retry key leads to undesirable behaviour. Setting this option false causes
 However, in some dialup environments hosts are assigned a different IP address
 each time they connect. In this situation the use of the IP address as part of
 the retry key leads to undesirable behaviour. Setting this option false causes

-Exim to use only the host name. This should normally be done on a separate
-instance of the &(smtp)& transport, set up specially to handle the dialup
-hosts.
+Exim to use only the host name.
+.new
+Since it is expanded it can be made to depend on the host or domain.
+.wen

 
 
 .option serialize_hosts smtp "host list&!!" unset
 
 
 .option serialize_hosts smtp "host list&!!" unset


@@ -22192,6 +23461,17 @@ This option specifies a certificate revocation list. The expanded value must
 be the name of a file that contains a CRL in PEM format.
 
 
 be the name of a file that contains a CRL in PEM format.
 
 

+.option tls_dh_min_bits smtp integer 1024
+.cindex "TLS" "Diffie-Hellman minimum acceptable size"
+When establishing a TLS session, if a ciphersuite which uses Diffie-Hellman
+key agreement is negotiated, the server will provide a large prime number
+for use.  This option establishes the minimum acceptable size of that number.
+If the parameter offered by the server is too small, then the TLS handshake
+will fail.
+
+Only supported when using GnuTLS.
+
+

 .option tls_privatekey smtp string&!! unset
 .cindex "TLS" "client private key, location of"
 .vindex "&$host$&"
 .option tls_privatekey smtp string&!! unset
 .cindex "TLS" "client private key, location of"
 .vindex "&$host$&"


@@ -22221,6 +23501,22 @@ ciphers is a preference order.
 
 
 
 
 
 

+.option tls_sni smtp string&!! unset
+.cindex "TLS" "Server Name Indication"
+.vindex "&$tls_sni$&"
+If this option is set then it sets the $tls_out_sni variable and causes any
+TLS session to pass this value as the Server Name Indication extension to
+the remote side, which can be used by the remote side to select an appropriate
+certificate and private key for the session.
+
+See &<<SECTtlssni>>& for more information.
+
+Note that for OpenSSL, this feature requires a build of OpenSSL that supports
+TLS extensions.
+
+
+
+

 .option tls_tempfail_tryclear smtp boolean true
 .cindex "4&'xx'& responses" "to STARTTLS"
 When the server host is not in &%hosts_require_tls%&, and there is a problem in
 .option tls_tempfail_tryclear smtp boolean true
 .cindex "4&'xx'& responses" "to STARTTLS"
 When the server host is not in &%hosts_require_tls%&, and there is a problem in


@@ -22234,20 +23530,81 @@ unknown state), opens a new one to the same host, and then tries the delivery
 in clear.
 
 
 in clear.
 
 

-.option tls_verify_certificates smtp string&!! unset
+.new
+.option tls_try_verify_hosts smtp "host list&!!" *
+.wen
+.cindex "TLS" "server certificate verification"
+.cindex "certificate" "verification of server"
+This option gives a list of hosts for which, on encrypted connections,
+certificate verification will be tried but need not succeed.
+The &%tls_verify_certificates%& option must also be set.
+Note that unless the host is in this list
+TLS connections will be denied to hosts using self-signed certificates
+when &%tls_verify_certificates%& is matched.
+The &$tls_out_certificate_verified$& variable is set when
+certificate verification succeeds.
+
+
+.new
+.option tls_verify_cert_hostnames smtp "host list&!!" *
+.cindex "TLS" "server certificate hostname verification"
+.cindex "certificate" "verification of server"
+This option give a list of hosts for which,
+while verifying the server certificate,
+checks will be included on the host name
+(note that this will generally be the result of a DNS MX lookup)
+versus Subject and Subject-Alternate-Name fields.  Wildcard names are permitted
+limited to being the initial component of a 3-or-more component FQDN.
+
+There is no equivalent checking on client certificates.
+.wen
+
+
+.new
+.option tls_verify_certificates smtp string&!! system

 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 .vindex "&$host$&"
 .vindex "&$host_address$&"
 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 .vindex "&$host$&"
 .vindex "&$host_address$&"

-The value of this option must be the absolute path to a file containing
-permitted server certificates, for use when setting up an encrypted connection.
-Alternatively, if you are using OpenSSL, you can set
-&%tls_verify_certificates%& to the name of a directory containing certificate
-files. This does not work with GnuTLS; the option must be set to the name of a
-single file if you are using GnuTLS. The values of &$host$& and
+The value of this option must be either the
+word "system"
+or the absolute path to
+a file or directory containing permitted certificates for servers,
+for use when setting up an encrypted connection.
+
+The "system" value for the option will use a location compiled into the SSL library.
+This is not available for GnuTLS versions preceding 3.0.20; a value of "system"
+is taken as empty and an explicit location
+must be specified.
+
+The use of a directory for the option value is not avilable for GnuTLS versions
+preceding 3.3.6 and a single file must be used.
+.wen
+
+With OpenSSL the certificates specified
+explicitly
+either by file or directory
+are added to those given by the system default location.
+
+The values of &$host$& and

 &$host_address$& are set to the name and address of the server during the
 expansion of this option. See chapter &<<CHAPTLS>>& for details of TLS.
 
 &$host_address$& are set to the name and address of the server during the
 expansion of this option. See chapter &<<CHAPTLS>>& for details of TLS.
 

+For back-compatability,
+if neither tls_verify_hosts nor tls_try_verify_hosts are set
+(a single-colon empty list counts as being set)
+and certificate verification fails the TLS connection is closed.
+
+
+.option tls_verify_hosts smtp "host list&!!" unset
+.cindex "TLS" "server certificate verification"
+.cindex "certificate" "verification of server"
+This option gives a list of hosts for which. on encrypted connections,
+certificate verification must succeed.
+The &%tls_verify_certificates%& option must also be set.
+If both this option and &%tls_try_verify_hosts%& are unset
+operation is as if this option selected all hosts.
+

 
 
 
 
 
 


@@ -22874,7 +24231,7 @@ In practice, almost all rules start with a domain name pattern without a local
 part.
 
 .cindex "regular expressions" "in retry rules"
 part.
 
 .cindex "regular expressions" "in retry rules"

-&*Warning*&: If you use a regular expression in a routing rule pattern, it
+&*Warning*&: If you use a regular expression in a retry rule pattern, it

 must match a complete address, not just a domain, because that is how regular
 expressions work in address lists.
 .display
 must match a complete address, not just a domain, because that is how regular
 expressions work in address lists.
 .display


@@ -23396,18 +24753,15 @@ included by setting
 .code
 AUTH_CRAM_MD5=yes
 AUTH_CYRUS_SASL=yes
 .code
 AUTH_CRAM_MD5=yes
 AUTH_CYRUS_SASL=yes

-.new

 AUTH_DOVECOT=yes
 AUTH_GSASL=yes
 AUTH_HEIMDAL_GSSAPI=yes
 AUTH_DOVECOT=yes
 AUTH_GSASL=yes
 AUTH_HEIMDAL_GSSAPI=yes

-.wen

 AUTH_PLAINTEXT=yes
 AUTH_SPA=yes
 .endd
 in &_Local/Makefile_&, respectively. The first of these supports the CRAM-MD5
 authentication mechanism (RFC 2195), and the second provides an interface to
 the Cyrus SASL authentication library.
 AUTH_PLAINTEXT=yes
 AUTH_SPA=yes
 .endd
 in &_Local/Makefile_&, respectively. The first of these supports the CRAM-MD5
 authentication mechanism (RFC 2195), and the second provides an interface to
 the Cyrus SASL authentication library.

-.new

 The third is an interface to Dovecot's authentication system, delegating the
 work via a socket interface.
 The fourth provides an interface to the GNU SASL authentication library, which
 The third is an interface to Dovecot's authentication system, delegating the
 work via a socket interface.
 The fourth provides an interface to the GNU SASL authentication library, which


@@ -23418,7 +24772,6 @@ The sixth can be configured to support
 the PLAIN authentication mechanism (RFC 2595) or the LOGIN mechanism, which is
 not formally documented, but used by several MUAs. The seventh authenticator
 supports Microsoft's &'Secure Password Authentication'& mechanism.
 the PLAIN authentication mechanism (RFC 2595) or the LOGIN mechanism, which is
 not formally documented, but used by several MUAs. The seventh authenticator
 supports Microsoft's &'Secure Password Authentication'& mechanism.

-.wen

 
 The authenticators are configured using the same syntax as other drivers (see
 section &<<SECTfordricon>>&). If no authenticators are required, no
 
 The authenticators are configured using the same syntax as other drivers (see
 section &<<SECTfordricon>>&). If no authenticators are required, no


@@ -23450,7 +24803,6 @@ The remainder of this chapter covers the generic options for the
 authenticators, followed by general discussion of the way authentication works
 in Exim.
 
 authenticators, followed by general discussion of the way authentication works
 in Exim.
 

-.new

 &*Beware:*& the meaning of &$auth1$&, &$auth2$&, ... varies on a per-driver and
 per-mechanism basis.  Please read carefully to determine which variables hold
 account labels such as usercodes and which hold passwords or other
 &*Beware:*& the meaning of &$auth1$&, &$auth2$&, ... varies on a per-driver and
 per-mechanism basis.  Please read carefully to determine which variables hold
 account labels such as usercodes and which hold passwords or other


@@ -23472,7 +24824,6 @@ A &'realm'& is a text string, typically a domain name, presented by a server
 to a client to help it select an account and credentials to use.  In some
 mechanisms, the client and server provably agree on the realm, but clients
 typically can not treat the realm as secure data to be blindly trusted.
 to a client to help it select an account and credentials to use.  In some
 mechanisms, the client and server provably agree on the realm, but clients
 typically can not treat the realm as secure data to be blindly trusted.

-.wen

 
 
 
 
 
 


@@ -23486,11 +24837,14 @@ When Exim is authenticating as a client, it skips any authenticator whose
 used, for example, to skip plain text authenticators when the connection is not
 encrypted by a setting such as:
 .code
 used, for example, to skip plain text authenticators when the connection is not
 encrypted by a setting such as:
 .code

-client_condition = ${if !eq{$tls_cipher}{}}
+client_condition = ${if !eq{$tls_out_cipher}{}}

 .endd
 .endd

-(Older documentation incorrectly states that &$tls_cipher$& contains the cipher
-used for incoming messages. In fact, during SMTP delivery, it contains the
-cipher used for the delivery.)
+
+
+.option client_set_id authenticators string&!! unset
+When client authentication succeeds, this condition is expanded; the
+result is used in the log lines for outbound messasges.
+Typically it will be the user name used for authentication.

 
 
 .option driver authenticators string unset
 
 
 .option driver authenticators string unset


@@ -23520,10 +24874,8 @@ This option must be set for a &%plaintext%& server authenticator, where it
 is used directly to control authentication. See section &<<SECTplainserver>>&
 for details.
 
 is used directly to control authentication. See section &<<SECTplainserver>>&
 for details.
 

-.new

 For the &(gsasl)& authenticator, this option is required for various
 mechanisms; see chapter &<<CHAPgsasl>>& for details.
 For the &(gsasl)& authenticator, this option is required for various
 mechanisms; see chapter &<<CHAPgsasl>>& for details.

-.wen

 
 For the other authenticators, &%server_condition%& can be used as an additional
 authentication or authorization mechanism that is applied after the other
 
 For the other authenticators, &%server_condition%& can be used as an additional
 authentication or authorization mechanism that is applied after the other


@@ -23652,10 +25004,10 @@ authentication mechanisms. For example, it can be used to restrict the
 advertisement of a particular mechanism to encrypted connections, by a setting
 such as:
 .code
 advertisement of a particular mechanism to encrypted connections, by a setting
 such as:
 .code

-server_advertise_condition = ${if eq{$tls_cipher}{}{no}{yes}}
+server_advertise_condition = ${if eq{$tls_in_cipher}{}{no}{yes}}

 .endd
 .endd

-.vindex "&$tls_cipher$&"
-If the session is encrypted, &$tls_cipher$& is not empty, and so the expansion
+.vindex "&$tls_in_cipher$&"
+If the session is encrypted, &$tls_in_cipher$& is not empty, and so the expansion

 yields &"yes"&, which allows the advertisement to happen.
 
 When an Exim server receives an AUTH command from a client, it rejects it
 yields &"yes"&, which allows the advertisement to happen.
 
 When an Exim server receives an AUTH command from a client, it rejects it


@@ -23862,7 +25214,7 @@ to be returned. If the result of a successful expansion is an empty string,
 expansion is &"1"&, &"yes"&, or &"true"&, authentication succeeds and the
 generic &%server_set_id%& option is expanded and saved in &$authenticated_id$&.
 For any other result, a temporary error code is returned, with the expanded
 expansion is &"1"&, &"yes"&, or &"true"&, authentication succeeds and the
 generic &%server_set_id%& option is expanded and saved in &$authenticated_id$&.
 For any other result, a temporary error code is returned, with the expanded

-string as the error text.
+string as the error text

 
 &*Warning*&: If you use a lookup in the expansion to find the user's
 password, be sure to make the authentication fail if the user is unknown.
 
 &*Warning*&: If you use a lookup in the expansion to find the user's
 password, be sure to make the authentication fail if the user is unknown.


@@ -23985,9 +25337,10 @@ login:
   server_prompts = Username:: : Password::
   server_condition = ${if and{{ \
     !eq{}{$auth1} }{ \
   server_prompts = Username:: : Password::
   server_condition = ${if and{{ \
     !eq{}{$auth1} }{ \

-    ldapauth{user="cn=${quote_ldap_dn:$auth1},ou=people,o=example.org" \
-             pass=${quote:$auth2} \
-             ldap://ldap.example.org/} }} }
+    ldapauth{\
+      user="uid=${quote_ldap_dn:$auth1},ou=people,o=example.org" \
+      pass=${quote:$auth2} \
+      ldap://ldap.example.org/} }} }

   server_set_id = uid=$auth1,ou=people,o=example.org
 .endd
 We have to check that the username is not empty before using it, because LDAP
   server_set_id = uid=$auth1,ou=people,o=example.org
 .endd
 We have to check that the username is not empty before using it, because LDAP


@@ -24129,6 +25482,18 @@ lookup_cram:
 Note that this expansion explicitly forces failure if the lookup fails
 because &$auth1$& contains an unknown user name.
 
 Note that this expansion explicitly forces failure if the lookup fails
 because &$auth1$& contains an unknown user name.
 

+As another example, if you wish to re-use a Cyrus SASL sasldb2 file without
+using the relevant libraries, you need to know the realm to specify in the
+lookup and then ask for the &"userPassword"& attribute for that user in that
+realm, with:
+.code
+cyrusless_crammd5:
+  driver = cram_md5
+  public_name = CRAM-MD5
+  server_secret = ${lookup{$auth1:mail.example.org:userPassword}\
+                  dbmjz{/etc/sasldb2}}
+  server_set_id = $auth1
+.endd

 
 .section "Using cram_md5 as a client" "SECID177"
 .cindex "options" "&(cram_md5)& authenticator (client)"
 
 .section "Using cram_md5 as a client" "SECID177"
 .cindex "options" "&(cram_md5)& authenticator (client)"


@@ -24203,7 +25568,7 @@ Kerberos, note that because of limitations in the GSSAPI interface,
 changing the server keytab might need to be communicated down to the Kerberos
 layer independently. The mechanism for doing so is dependent upon the Kerberos
 implementation.
 changing the server keytab might need to be communicated down to the Kerberos
 layer independently. The mechanism for doing so is dependent upon the Kerberos
 implementation.

-.new
+

 For example, for older releases of Heimdal, the environment variable KRB5_KTNAME
 may be set to point to an alternative keytab file. Exim will pass this
 variable through from its own inherited environment when started as root or the
 For example, for older releases of Heimdal, the environment variable KRB5_KTNAME
 may be set to point to an alternative keytab file. Exim will pass this
 variable through from its own inherited environment when started as root or the


@@ -24212,7 +25577,6 @@ With newer releases of Heimdal, a setuid Exim may cause Heimdal to discard the
 environment variable.  In practice, for those releases, the Cyrus authenticator
 is not a suitable interface for GSSAPI (Kerberos) support.  Instead, consider
 the &(heimdal_gssapi)& authenticator, described in chapter &<<CHAPheimdalgss>>&
 environment variable.  In practice, for those releases, the Cyrus authenticator
 is not a suitable interface for GSSAPI (Kerberos) support.  Instead, consider
 the &(heimdal_gssapi)& authenticator, described in chapter &<<CHAPheimdalgss>>&

-.wen

 
 
 .section "Using cyrus_sasl as a server" "SECID178"
 
 
 .section "Using cyrus_sasl as a server" "SECID178"


@@ -24243,7 +25607,7 @@ sasl:
   server_set_id = $auth1
 .endd
 
   server_set_id = $auth1
 .endd
 

-.option server_realm cyrus_sasl string unset
+.option server_realm cyrus_sasl string&!! unset

 This specifies the SASL realm that the server claims to be in.
 
 
 This specifies the SASL realm that the server claims to be in.
 
 


@@ -24282,6 +25646,7 @@ but it is present in many binary distributions.
 .scindex IIDdcotauth2 "authenticators" "&(dovecot)&"
 This authenticator is an interface to the authentication facility of the
 Dovecot POP/IMAP server, which can support a number of authentication methods.
 .scindex IIDdcotauth2 "authenticators" "&(dovecot)&"
 This authenticator is an interface to the authentication facility of the
 Dovecot POP/IMAP server, which can support a number of authentication methods.

+Note that Dovecot must be configured to use auth-client not auth-userdb.

 If you are using Dovecot to authenticate POP/IMAP clients, it might be helpful
 to use the same mechanisms for SMTP authentication. This is a server
 authenticator only. There is only one option:
 If you are using Dovecot to authenticate POP/IMAP clients, it might be helpful
 to use the same mechanisms for SMTP authentication. This is a server
 authenticator only. There is only one option:


@@ -24297,7 +25662,7 @@ dovecot_plain:
   driver = dovecot
   public_name = PLAIN
   server_socket = /var/run/dovecot/auth-client
   driver = dovecot
   public_name = PLAIN
   server_socket = /var/run/dovecot/auth-client

-  server_set_id = $auth2
+  server_set_id = $auth1

 
 dovecot_ntlm:
   driver = dovecot
 
 dovecot_ntlm:
   driver = dovecot


@@ -24317,7 +25682,6 @@ who authenticated is placed in &$auth1$&.
 
 . ////////////////////////////////////////////////////////////////////////////
 . ////////////////////////////////////////////////////////////////////////////
 
 . ////////////////////////////////////////////////////////////////////////////
 . ////////////////////////////////////////////////////////////////////////////

-.new

 .chapter "The gsasl authenticator" "CHAPgsasl"
 .scindex IIDgsaslauth1 "&(gsasl)& authenticator"
 .scindex IIDgsaslauth2 "authenticators" "&(gsasl)&"
 .chapter "The gsasl authenticator" "CHAPgsasl"
 .scindex IIDgsaslauth1 "&(gsasl)& authenticator"
 .scindex IIDgsaslauth2 "authenticators" "&(gsasl)&"


@@ -24331,14 +25695,14 @@ who authenticated is placed in &$auth1$&.
 .cindex "authentication" "CRAM-MD5"
 .cindex "authentication" "SCRAM-SHA-1"
 The &(gsasl)& authenticator provides server integration for the GNU SASL
 .cindex "authentication" "CRAM-MD5"
 .cindex "authentication" "SCRAM-SHA-1"
 The &(gsasl)& authenticator provides server integration for the GNU SASL

-library and the mechanisms it provides.  This is new as of the 4.78 release
+library and the mechanisms it provides.  This is new as of the 4.80 release

 and there are a few areas where the library does not let Exim smoothly
 scale to handle future authentication mechanisms, so no guarantee can be
 made that any particular new authentication mechanism will be supported
 without code changes in Exim.
 
 
 and there are a few areas where the library does not let Exim smoothly
 scale to handle future authentication mechanisms, so no guarantee can be
 made that any particular new authentication mechanism will be supported
 without code changes in Exim.
 
 

-.option server_channelbinding gsasl bool false
+.option server_channelbinding gsasl boolean false

 Some authentication mechanisms are able to use external context at both ends
 of the session to bind the authentication to that context, and fail the
 authentication process if that context differs.  Specifically, some TLS
 Some authentication mechanisms are able to use external context at both ends
 of the session to bind the authentication to that context, and fail the
 authentication process if that context differs.  Specifically, some TLS


@@ -24458,12 +25822,24 @@ An &'anonymous token'& is something passed along as an unauthenticated
 identifier; this is analogous to FTP anonymous authentication passing an
 email address, or software-identifier@, as the "password".
 
 identifier; this is analogous to FTP anonymous authentication passing an
 email address, or software-identifier@, as the "password".
 

-.wen
+
+An example showing the password having the realm specified in the callback
+and demonstrating a Cyrus SASL to GSASL migration approach is:
+.code
+gsasl_cyrusless_crammd5:
+  driver = gsasl
+  public_name = CRAM-MD5
+  server_realm = imap.example.org
+  server_password = ${lookup{$auth1:$auth3:userPassword}\
+                    dbmjz{/etc/sasldb2}{$value}fail}
+  server_set_id = ${quote:$auth1}
+  server_condition = yes
+.endd
+

 
 . ////////////////////////////////////////////////////////////////////////////
 . ////////////////////////////////////////////////////////////////////////////
 
 
 . ////////////////////////////////////////////////////////////////////////////
 . ////////////////////////////////////////////////////////////////////////////
 

-.new

 .chapter "The heimdal_gssapi authenticator" "CHAPheimdalgss"
 .scindex IIDheimdalgssauth1 "&(heimdal_gssapi)& authenticator"
 .scindex IIDheimdalgssauth2 "authenticators" "&(heimdal_gssapi)&"
 .chapter "The heimdal_gssapi authenticator" "CHAPheimdalgss"
 .scindex IIDheimdalgssauth1 "&(heimdal_gssapi)& authenticator"
 .scindex IIDheimdalgssauth2 "authenticators" "&(heimdal_gssapi)&"


@@ -24506,10 +25882,10 @@ role suffix.  For instance, &"joe/admin@EXAMPLE.ORG"&.
 .next
 .vindex "&$auth2$&"
 &$auth2$&: the &'authorization id'&, sent within SASL encapsulation after
 .next
 .vindex "&$auth2$&"
 &$auth2$&: the &'authorization id'&, sent within SASL encapsulation after

-authentication.
+authentication.  If that was empty, this will also be set to the
+GSS Display Name.

 .endlist
 
 .endlist
 

-.wen

 
 . ////////////////////////////////////////////////////////////////////////////
 . ////////////////////////////////////////////////////////////////////////////
 
 . ////////////////////////////////////////////////////////////////////////////
 . ////////////////////////////////////////////////////////////////////////////


@@ -24692,36 +26068,56 @@ include files and libraries for GnuTLS can be found.
 There are some differences in usage when using GnuTLS instead of OpenSSL:
 
 .ilist
 There are some differences in usage when using GnuTLS instead of OpenSSL:
 
 .ilist

-The &%tls_verify_certificates%& option must contain the name of a file, not the
-name of a directory (for OpenSSL it can be either).
+The &%tls_verify_certificates%& option
+cannot be the path of a directory
+for GnuTLS versions before 3.3.6
+(for later versions, or OpenSSL, it can be either).

 .next
 .next

-The &%tls_dhparam%& option is ignored, because early versions of GnuTLS had no
-facility for varying its Diffie-Hellman parameters. I understand that this has
-changed, but Exim has not been updated to provide this facility.
+The default value for &%tls_dhparam%& differs for historical reasons.

 .next
 .next

-.vindex "&$tls_peerdn$&"
+.vindex "&$tls_in_peerdn$&"
+.vindex "&$tls_out_peerdn$&"

 Distinguished Name (DN) strings reported by the OpenSSL library use a slash for
 separating fields; GnuTLS uses commas, in accordance with RFC 2253. This
 Distinguished Name (DN) strings reported by the OpenSSL library use a slash for
 separating fields; GnuTLS uses commas, in accordance with RFC 2253. This

-affects the value of the &$tls_peerdn$& variable.
+affects the value of the &$tls_in_peerdn$& and &$tls_out_peerdn$& variables.

 .next
 OpenSSL identifies cipher suites using hyphens as separators, for example:
 .next
 OpenSSL identifies cipher suites using hyphens as separators, for example:

-DES-CBC3-SHA. GnuTLS uses underscores, for example: RSA_ARCFOUR_SHA. What is
-more, OpenSSL complains if underscores are present in a cipher list. To make
-life simpler, Exim changes underscores to hyphens for OpenSSL and hyphens to
-underscores for GnuTLS when processing lists of cipher suites in the
+DES-CBC3-SHA. GnuTLS historically used underscores, for example:
+RSA_ARCFOUR_SHA. What is more, OpenSSL complains if underscores are present
+in a cipher list. To make life simpler, Exim changes underscores to hyphens
+for OpenSSL and passes the string unchanged to GnuTLS (expecting the library
+to handle its own older variants) when processing lists of cipher suites in the

 &%tls_require_ciphers%& options (the global option and the &(smtp)& transport
 option).
 .next
 The &%tls_require_ciphers%& options operate differently, as described in the
 sections &<<SECTreqciphssl>>& and &<<SECTreqciphgnu>>&.
 &%tls_require_ciphers%& options (the global option and the &(smtp)& transport
 option).
 .next
 The &%tls_require_ciphers%& options operate differently, as described in the
 sections &<<SECTreqciphssl>>& and &<<SECTreqciphgnu>>&.

+.next
+The &%tls_dh_min_bits%& SMTP transport option is only honoured by GnuTLS.
+When using OpenSSL, this option is ignored.
+(If an API is found to let OpenSSL be configured in this way,
+let the Exim Maintainers know and we'll likely use it).
+.next
+Some other recently added features may only be available in one or the other.
+This should be documented with the feature.  If the documentation does not
+explicitly state that the feature is infeasible in the other TLS
+implementation, then patches are welcome.

 .endlist
 
 
 .endlist
 
 

-.section "GnuTLS parameter computation" "SECID181"
+.section "GnuTLS parameter computation" "SECTgnutlsparam"
+This section only applies if &%tls_dhparam%& is set to &`historic`& or to
+an explicit path; if the latter, then the text about generation still applies,
+but not the chosen filename.
+By default, as of Exim 4.80 a hard-coded D-H prime is used.
+See the documentation of &%tls_dhparam%& for more information.
+

 GnuTLS uses D-H parameters that may take a substantial amount of time
 to compute. It is unreasonable to re-compute them for every TLS session.
 Therefore, Exim keeps this data in a file in its spool directory, called
 GnuTLS uses D-H parameters that may take a substantial amount of time
 to compute. It is unreasonable to re-compute them for every TLS session.
 Therefore, Exim keeps this data in a file in its spool directory, called

-&_gnutls-params_&. The file is owned by the Exim user and is readable only by
+&_gnutls-params-NNNN_& for some value of NNNN, corresponding to the number
+of bits requested.
+The file is owned by the Exim user and is readable only by

 its owner. Every Exim process that start up GnuTLS reads the D-H
 parameters from this file. If the file does not exist, the first Exim process
 that needs it computes the data and writes it to a temporary file which is
 its owner. Every Exim process that start up GnuTLS reads the D-H
 parameters from this file. If the file does not exist, the first Exim process
 that needs it computes the data and writes it to a temporary file which is


@@ -24731,6 +26127,10 @@ place, new Exim processes immediately start using it.
 
 For maximum security, the parameters that are stored in this file should be
 recalculated periodically, the frequency depending on your paranoia level.
 
 For maximum security, the parameters that are stored in this file should be
 recalculated periodically, the frequency depending on your paranoia level.

+If you are avoiding using the fixed D-H primes published in RFCs, then you
+are concerned about some advanced attacks and will wish to do this; if you do
+not regenerate then you might as well stick to the standard primes.
+

 Arranging this is easy in principle; just delete the file when you want new
 values to be computed. However, there may be a problem. The calculation of new
 parameters needs random numbers, and these are obtained from &_/dev/random_&.
 Arranging this is easy in principle; just delete the file when you want new
 values to be computed. However, there may be a problem. The calculation of new
 parameters needs random numbers, and these are obtained from &_/dev/random_&.


@@ -24739,26 +26139,54 @@ until enough randomness (entropy) is available. This may cause Exim to hang for
 a substantial amount of time, causing timeouts on incoming connections.
 
 The solution is to generate the parameters externally to Exim. They are stored
 a substantial amount of time, causing timeouts on incoming connections.
 
 The solution is to generate the parameters externally to Exim. They are stored

-in &_gnutls-params_& in PEM format, which means that they can be generated
-externally using the &(certtool)& command that is part of GnuTLS.
+in &_gnutls-params-N_& in PEM format, which means that they can be
+generated externally using the &(certtool)& command that is part of GnuTLS.

 
 To replace the parameters with new ones, instead of deleting the file
 and letting Exim re-create it, you can generate new parameters using
 &(certtool)& and, when this has been done, replace Exim's cache file by
 renaming. The relevant commands are something like this:
 .code
 
 To replace the parameters with new ones, instead of deleting the file
 and letting Exim re-create it, you can generate new parameters using
 &(certtool)& and, when this has been done, replace Exim's cache file by
 renaming. The relevant commands are something like this:
 .code

+# ls
+[ look for file; assume gnutls-params-2236 is the most recent ]

 # rm -f new-params
 # touch new-params
 # chown exim:exim new-params
 # rm -f new-params
 # touch new-params
 # chown exim:exim new-params

+# chmod 0600 new-params
+# certtool --generate-dh-params --bits 2236 >>new-params
+# openssl dhparam -noout -text -in new-params | head
+[ check the first line, make sure it's not more than 2236;
+  if it is, then go back to the start ("rm") and repeat
+  until the size generated is at most the size requested ]

 # chmod 0400 new-params
 # chmod 0400 new-params

-# certtool --generate-privkey --bits 512 >new-params
-# echo "" >>new-params
-# certtool --generate-dh-params --bits 1024 >> new-params
-# mv new-params gnutls-params
+# mv new-params gnutls-params-2236

 .endd
 If Exim never has to generate the parameters itself, the possibility of
 stalling is removed.
 
 .endd
 If Exim never has to generate the parameters itself, the possibility of
 stalling is removed.
 

+The filename changed in Exim 4.80, to gain the -bits suffix.  The value which
+Exim will choose depends upon the version of GnuTLS in use.  For older GnuTLS,
+the value remains hard-coded in Exim as 1024.  As of GnuTLS 2.12.x, there is
+a way for Exim to ask for the "normal" number of bits for D-H public-key usage,
+and Exim does so.  This attempt to remove Exim from TLS policy decisions
+failed, as GnuTLS 2.12 returns a value higher than the current hard-coded limit
+of the NSS library.  Thus Exim gains the &%tls_dh_max_bits%& global option,
+which applies to all D-H usage, client or server.  If the value returned by
+GnuTLS is greater than &%tls_dh_max_bits%& then the value will be clamped down
+to &%tls_dh_max_bits%&.  The default value has been set at the current NSS
+limit, which is still much higher than Exim historically used.
+
+The filename and bits used will change as the GnuTLS maintainers change the
+value for their parameter &`GNUTLS_SEC_PARAM_NORMAL`&, as clamped by
+&%tls_dh_max_bits%&.  At the time of writing (mid 2012), GnuTLS 2.12 recommends
+2432 bits, while NSS is limited to 2236 bits.
+
+In fact, the requested value will be *lower* than &%tls_dh_max_bits%&, to
+increase the chance of the generated prime actually being within acceptable
+bounds, as GnuTLS has been observed to overshoot.  Note the check step in the
+procedure above.  There is no sane procedure available to Exim to double-check
+the size of the generated prime, so it might still be too large.
+

 
 .section "Requiring specific ciphers in OpenSSL" "SECTreqciphssl"
 .cindex "TLS" "requiring specific ciphers (OpenSSL)"
 
 .section "Requiring specific ciphers in OpenSSL" "SECTreqciphssl"
 .cindex "TLS" "requiring specific ciphers (OpenSSL)"


@@ -24767,7 +26195,10 @@ There is a function in the OpenSSL library that can be passed a list of cipher
 suites before the cipher negotiation takes place. This specifies which ciphers
 are acceptable. The list is colon separated and may contain names like
 DES-CBC3-SHA. Exim passes the expanded value of &%tls_require_ciphers%&
 suites before the cipher negotiation takes place. This specifies which ciphers
 are acceptable. The list is colon separated and may contain names like
 DES-CBC3-SHA. Exim passes the expanded value of &%tls_require_ciphers%&

-directly to this function call. The following quotation from the OpenSSL
+directly to this function call.
+Many systems will install the OpenSSL manual-pages, so you may have
+&'ciphers(1)'& available to you.
+The following quotation from the OpenSSL

 documentation specifies what forms of item are allowed in the cipher string:
 
 .ilist
 documentation specifies what forms of item are allowed in the cipher string:
 
 .ilist


@@ -24804,6 +26235,24 @@ includes any ciphers already present they will be ignored: that is, they will
 not be moved to the end of the list.
 .endlist
 
 not be moved to the end of the list.
 .endlist
 

+The OpenSSL &'ciphers(1)'& command may be used to test the results of a given
+string:
+.code
+# note single-quotes to get ! past any shell history expansion
+$ openssl ciphers 'HIGH:!MD5:!SHA1'
+.endd
+
+This example will let the library defaults be permitted on the MX port, where
+there's probably no identity verification anyway, but ups the ante on the
+submission ports where the administrator might have some influence on the
+choice of clients used:
+.code
+# OpenSSL variant; see man ciphers(1)
+tls_require_ciphers = ${if =={$received_port}{25}\
+                           {DEFAULT}\
+                           {HIGH:!MD5:!SHA1}}
+.endd
+

 
 
 .section "Requiring specific ciphers or other parameters in GnuTLS" &&&
 
 
 .section "Requiring specific ciphers or other parameters in GnuTLS" &&&


@@ -24813,84 +26262,51 @@ not be moved to the end of the list.
 .cindex "TLS" "specifying key exchange methods (GnuTLS)"
 .cindex "TLS" "specifying MAC algorithms (GnuTLS)"
 .cindex "TLS" "specifying protocols (GnuTLS)"
 .cindex "TLS" "specifying key exchange methods (GnuTLS)"
 .cindex "TLS" "specifying MAC algorithms (GnuTLS)"
 .cindex "TLS" "specifying protocols (GnuTLS)"

+.cindex "TLS" "specifying priority string (GnuTLS)"

 .oindex "&%tls_require_ciphers%&" "GnuTLS"
 .oindex "&%tls_require_ciphers%&" "GnuTLS"

-The GnuTLS library allows the caller to specify separate lists of permitted key
-exchange methods, main cipher algorithms, MAC algorithms, and protocols.
-Unfortunately, these lists are numerical, and the library does not have a
-function for turning names into numbers. Consequently, lists of recognized
-names have to be built into the application. The permitted key exchange
-methods, ciphers, and MAC algorithms may be used in any combination to form a
-cipher suite. This is unlike OpenSSL, where complete cipher suite names are
-passed to its control function.
-
-For compatibility with OpenSSL, the &%tls_require_ciphers%& option can be set
-to complete cipher suite names such as RSA_ARCFOUR_SHA, but for GnuTLS this
-option controls only the cipher algorithms. Exim searches each item in the
-list for the name of an available algorithm. For example, if the list
-contains RSA_AES_SHA, then AES is recognized, and the behaviour is exactly
-the same as if just AES were given.
-
-.oindex "&%gnutls_require_kx%&"
-.oindex "&%gnutls_require_mac%&"
-.oindex "&%gnutls_require_protocols%&"
-There are additional options called &%gnutls_require_kx%&,
-&%gnutls_require_mac%&, and &%gnutls_require_protocols%& that can be used to
-restrict the key exchange methods, MAC algorithms, and protocols, respectively.
-These options are ignored if OpenSSL is in use.
-
-All four options are available as global options, controlling how Exim
-behaves as a server, and also as options of the &(smtp)& transport, controlling
-how Exim behaves as a client. All the values are string expanded. After
-expansion, the values must be colon-separated lists, though the separator
-can be changed in the usual way.
-
-Each of the four lists starts out with a default set of algorithms. If the
-first item in a list does &'not'& start with an exclamation mark, all the
-default items are deleted. In this case, only those that are explicitly
-specified can be used. If the first item in a list &'does'& start with an
-exclamation mark, the defaults are left on the list.
-
-Then, any item that starts with an exclamation mark causes the relevant
-entry to be removed from the list, and any item that does not start with an
-exclamation mark causes a new entry to be added to the list. Unrecognized
-items in the list are ignored. Thus:
-.code
-tls_require_ciphers = !ARCFOUR
-.endd
-allows all the defaults except ARCFOUR, whereas
-.code
-tls_require_ciphers = AES : 3DES
-.endd
-allows only cipher suites that use AES or 3DES.
-
-For &%tls_require_ciphers%& the recognized names are AES_256, AES_128, AES
-(both of the preceding), 3DES, ARCFOUR_128, ARCFOUR_40, and ARCFOUR (both of
-the preceding). The default list does not contain all of these; it just has
-AES_256, AES_128, 3DES, and ARCFOUR_128.
-
-For &%gnutls_require_kx%&, the recognized names are DHE_RSA, RSA (which
-includes DHE_RSA), DHE_DSS, and DHE (which includes both DHE_RSA and
-DHE_DSS). The default list contains RSA, DHE_DSS, DHE_RSA.
-
-For &%gnutls_require_mac%&, the recognized names are SHA (synonym SHA1), and
-MD5. The default list contains SHA, MD5.
+The GnuTLS library allows the caller to provide a "priority string", documented
+as part of the &[gnutls_priority_init]& function.  This is very similar to the
+ciphersuite specification in OpenSSL.
+
+The &%tls_require_ciphers%& option is treated as the GnuTLS priority string
+and controls both protocols and ciphers.
+
+The &%tls_require_ciphers%& option is available both as an global option,
+controlling how Exim behaves as a server, and also as an option of the
+&(smtp)& transport, controlling how Exim behaves as a client.  In both cases
+the value is string expanded.  The resulting string is not an Exim list and
+the string is given to the GnuTLS library, so that Exim does not need to be
+aware of future feature enhancements of GnuTLS.
+
+Documentation of the strings accepted may be found in the GnuTLS manual, under
+"Priority strings".  This is online as
+&url(http://www.gnutls.org/manual/html_node/Priority-Strings.html),
+but beware that this relates to GnuTLS 3, which may be newer than the version
+installed on your system.  If you are using GnuTLS 3,
+&url(http://www.gnutls.org/manual/gnutls.html#Listing-the-ciphersuites-in-a-priority-string, then the example code)
+on that site can be used to test a given string.

 
 

-.new
-For &%gnutls_require_protocols%&, the recognized names are TLS1.2, TLS1.1,
-TLS1.0, (TLS1) and SSL3.
-The default list contains TLS1.2, TLS1.1, TLS1.0, SSL3.
-TLS1 is an alias for TLS1.0, for backwards compatibility.
-For sufficiently old versions of the GnuTLS library, TLS1.2 or TLS1.1 might
-not be supported and will not be recognised by Exim.
-.wen
+For example:
+.code
+# Disable older versions of protocols
+tls_require_ciphers = NORMAL:%LATEST_RECORD_VERSION:-VERS-SSL3.0
+.endd

 
 

-In a server, the order of items in these lists is unimportant. The server
-advertises the availability of all the relevant cipher suites. However, in a
-client, the order in the &%tls_require_ciphers%& list specifies a preference
-order for the cipher algorithms. The first one in the client's list that is
-also advertised by the server is tried first. The default order is as listed
-above.
+Prior to Exim 4.80, an older API of GnuTLS was used, and Exim supported three
+additional options, "&%gnutls_require_kx%&", "&%gnutls_require_mac%&" and
+"&%gnutls_require_protocols%&".  &%tls_require_ciphers%& was an Exim list.

 
 

+This example will let the library defaults be permitted on the MX port, where
+there's probably no identity verification anyway, and lowers security further
+by increasing compatibility; but this ups the ante on the submission ports
+where the administrator might have some influence on the choice of clients
+used:
+.code
+# GnuTLS variant
+tls_require_ciphers = ${if =={$received_port}{25}\
+                           {NORMAL:%COMPAT}\
+                           {SECURE128}}
+.endd

 
 
 .section "Configuring an Exim server to use TLS" "SECID182"
 
 
 .section "Configuring an Exim server to use TLS" "SECID182"


@@ -24926,8 +26342,11 @@ tls_privatekey = /some/file/name
 These options are, in fact, expanded strings, so you can make them depend on
 the identity of the client that is connected if you wish. The first file
 contains the server's X509 certificate, and the second contains the private key
 These options are, in fact, expanded strings, so you can make them depend on
 the identity of the client that is connected if you wish. The first file
 contains the server's X509 certificate, and the second contains the private key

-that goes with it. These files need to be readable by the Exim user, and must
-always be given as full path names. They can be the same file if both the
+that goes with it. These files need to be
+PEM format and readable by the Exim user, and must
+always be given as full path names.
+The key must not be password-protected.
+They can be the same file if both the

 certificate and the key are contained within it. If &%tls_privatekey%& is not
 set, or if its expansion is forced to fail or results in an empty string, this
 is assumed to be the case. The certificate file may also contain intermediate
 certificate and the key are contained within it. If &%tls_privatekey%& is not
 set, or if its expansion is forced to fail or results in an empty string, this
 is assumed to be the case. The certificate file may also contain intermediate


@@ -24950,13 +26369,22 @@ this). There is one other option that may be needed in other situations. If
 tls_dhparam = /some/file/name
 .endd
 is set, the SSL library is initialized for the use of Diffie-Hellman ciphers
 tls_dhparam = /some/file/name
 .endd
 is set, the SSL library is initialized for the use of Diffie-Hellman ciphers

-with the parameters contained in the file. This increases the set of cipher
-suites that the server supports. See the command
+with the parameters contained in the file.
+Set this to &`none`& to disable use of DH entirely, by making no prime
+available:
+.code
+tls_dhparam = none
+.endd
+This may also be set to a string identifying a standard prime to be used for
+DH; if it is set to &`default`& or, for OpenSSL, is unset, then the prime
+used is &`ike23`&.  There are a few standard primes available, see the
+documentation for &%tls_dhparam%& for the complete list.
+
+See the command

 .code
 openssl dhparam
 .endd
 .code
 openssl dhparam
 .endd

-for a way of generating this data. At present, &%tls_dhparam%& is used only
-when Exim is linked with OpenSSL. It is ignored if GnuTLS is being used.
+for a way of generating file data.

 
 The strings supplied for these three options are expanded every time a client
 host connects. It is therefore possible to use different certificates and keys
 
 The strings supplied for these three options are expanded every time a client
 host connects. It is therefore possible to use different certificates and keys


@@ -24966,15 +26394,13 @@ forced to fail, Exim behaves as if the option is not set.
 
 .cindex "cipher" "logging"
 .cindex "log" "TLS cipher"
 
 .cindex "cipher" "logging"
 .cindex "log" "TLS cipher"

-.vindex "&$tls_cipher$&"
-The variable &$tls_cipher$& is set to the cipher suite that was negotiated for
+.vindex "&$tls_in_cipher$&"
+The variable &$tls_in_cipher$& is set to the cipher suite that was negotiated for

 an incoming TLS connection. It is included in the &'Received:'& header of an
 incoming message (by default &-- you can, of course, change this), and it is
 also included in the log line that records a message's arrival, keyed by
 &"X="&, unless the &%tls_cipher%& log selector is turned off. The &%encrypted%&
 condition can be used to test for specific cipher suites in ACLs.
 an incoming TLS connection. It is included in the &'Received:'& header of an
 incoming message (by default &-- you can, of course, change this), and it is
 also included in the log line that records a message's arrival, keyed by
 &"X="&, unless the &%tls_cipher%& log selector is turned off. The &%encrypted%&
 condition can be used to test for specific cipher suites in ACLs.

-(For outgoing SMTP deliveries, &$tls_cipher$& is reset &-- see section
-&<<SECID185>>&.)

 
 Once TLS has been established, the ACLs that run for subsequent SMTP commands
 can check the name of the cipher suite and vary their actions accordingly. The
 
 Once TLS has been established, the ACLs that run for subsequent SMTP commands
 can check the name of the cipher suite and vary their actions accordingly. The


@@ -24983,6 +26409,9 @@ example, OpenSSL uses the name DES-CBC3-SHA for the cipher suite which in other
 contexts is known as TLS_RSA_WITH_3DES_EDE_CBC_SHA. Check the OpenSSL or GnuTLS
 documentation for more details.
 
 contexts is known as TLS_RSA_WITH_3DES_EDE_CBC_SHA. Check the OpenSSL or GnuTLS
 documentation for more details.
 

+For outgoing SMTP deliveries, &$tls_out_cipher$& is used and logged
+(again depending on the &%tls_cipher%& log selector).
+

 
 .section "Requesting and verifying client certificates" "SECID183"
 .cindex "certificate" "verification of client"
 
 .section "Requesting and verifying client certificates" "SECID183"
 .cindex "certificate" "verification of client"


@@ -24993,8 +26422,12 @@ session with a client, you must set either &%tls_verify_hosts%& or
 apply to all TLS connections. For any host that matches one of these options,
 Exim requests a certificate as part of the setup of the TLS session. The
 contents of the certificate are verified by comparing it with a list of
 apply to all TLS connections. For any host that matches one of these options,
 Exim requests a certificate as part of the setup of the TLS session. The
 contents of the certificate are verified by comparing it with a list of

-expected certificates. These must be available in a file or,
-for OpenSSL only (not GnuTLS), a directory, identified by
+expected certificates.
+.new
+These may be the system default set (depending on library version),
+.wen
+an explicit file or,
+depending on library version, a directory, identified by

 &%tls_verify_certificates%&.
 
 A file can contain multiple certificates, concatenated end to end. If a
 &%tls_verify_certificates%&.
 
 A file can contain multiple certificates, concatenated end to end. If a


@@ -25019,29 +26452,98 @@ fact that no certificate was verified, and vary their actions accordingly. For
 example, you can insist on a certificate before accepting a message for
 relaying, but not when the message is destined for local delivery.
 
 example, you can insist on a certificate before accepting a message for
 relaying, but not when the message is destined for local delivery.
 

-.vindex "&$tls_peerdn$&"
+.vindex "&$tls_in_peerdn$&"

 When a client supplies a certificate (whether it verifies or not), the value of
 the Distinguished Name of the certificate is made available in the variable
 When a client supplies a certificate (whether it verifies or not), the value of
 the Distinguished Name of the certificate is made available in the variable

-&$tls_peerdn$& during subsequent processing of the message.
+&$tls_in_peerdn$& during subsequent processing of the message.

 
 .cindex "log" "distinguished name"
 Because it is often a long text string, it is not included in the log line or
 &'Received:'& header by default. You can arrange for it to be logged, keyed by
 &"DN="&, by setting the &%tls_peerdn%& log selector, and you can use
 &%received_header_text%& to change the &'Received:'& header. When no
 
 .cindex "log" "distinguished name"
 Because it is often a long text string, it is not included in the log line or
 &'Received:'& header by default. You can arrange for it to be logged, keyed by
 &"DN="&, by setting the &%tls_peerdn%& log selector, and you can use
 &%received_header_text%& to change the &'Received:'& header. When no

-certificate is supplied, &$tls_peerdn$& is empty.
+certificate is supplied, &$tls_in_peerdn$& is empty.

 
 
 .section "Revoked certificates" "SECID184"
 .cindex "TLS" "revoked certificates"
 .cindex "revocation list"
 .cindex "certificate" "revocation list"
 
 
 .section "Revoked certificates" "SECID184"
 .cindex "TLS" "revoked certificates"
 .cindex "revocation list"
 .cindex "certificate" "revocation list"

+.cindex "OCSP" "stapling"

 Certificate issuing authorities issue Certificate Revocation Lists (CRLs) when
 certificates are revoked. If you have such a list, you can pass it to an Exim
 server using the global option called &%tls_crl%& and to an Exim client using
 an identically named option for the &(smtp)& transport. In each case, the value
 of the option is expanded and must then be the name of a file that contains a
 CRL in PEM format.
 Certificate issuing authorities issue Certificate Revocation Lists (CRLs) when
 certificates are revoked. If you have such a list, you can pass it to an Exim
 server using the global option called &%tls_crl%& and to an Exim client using
 an identically named option for the &(smtp)& transport. In each case, the value
 of the option is expanded and must then be the name of a file that contains a
 CRL in PEM format.

+The downside is that clients have to periodically re-download a potentially huge
+file from every certificate authority they know of.
+
+The way with most moving parts at query time is Online Certificate
+Status Protocol (OCSP), where the client verifies the certificate
+against an OCSP server run by the CA.  This lets the CA track all
+usage of the certs.  It requires running software with access to the
+private key of the CA, to sign the responses to the OCSP queries.  OCSP
+is based on HTTP and can be proxied accordingly.
+
+The only widespread OCSP server implementation (known to this writer)
+comes as part of OpenSSL and aborts on an invalid request, such as
+connecting to the port and then disconnecting.  This requires
+re-entering the passphrase each time some random client does this.
+
+The third way is OCSP Stapling; in this, the server using a certificate
+issued by the CA periodically requests an OCSP proof of validity from
+the OCSP server, then serves it up inline as part of the TLS
+negotiation.   This approach adds no extra round trips, does not let the
+CA track users, scales well with number of certs issued by the CA and is
+resilient to temporary OCSP server failures, as long as the server
+starts retrying to fetch an OCSP proof some time before its current
+proof expires.  The downside is that it requires server support.
+
+Unless Exim is built with the support disabled,
+or with GnuTLS earlier than version 3.1.3,
+support for OCSP stapling is included.
+
+There is a global option called &%tls_ocsp_file%&.
+The file specified therein is expected to be in DER format, and contain
+an OCSP proof.  Exim will serve it as part of the TLS handshake.  This
+option will be re-expanded for SNI, if the &%tls_certificate%& option
+contains &`tls_in_sni`&, as per other TLS options.
+
+Exim does not at this time implement any support for fetching a new OCSP
+proof.  The burden is on the administrator to handle this, outside of
+Exim.  The file specified should be replaced atomically, so that the
+contents are always valid.  Exim will expand the &%tls_ocsp_file%& option
+on each connection, so a new file will be handled transparently on the
+next connection.
+
+When built with OpenSSL Exim will check for a valid next update timestamp
+in the OCSP proof; if not present, or if the proof has expired, it will be
+ignored.
+
+For the client to be able to verify the stapled OCSP the server must
+also supply, in its stapled information, any intermediate
+certificates for the chain leading to the OCSP proof from the signer
+of the server certificate.  There may be zero or one such. These
+intermediate certificates should be added to the server OCSP stapling
+file named by &%tls_ocsp_file%&.
+
+Note that the proof only covers the terminal server certificate,
+not any of the chain from CA to it.
+
+There is no current way to staple a proof for a client certificate.
+
+.code
+  A helper script "ocsp_fetch.pl" for fetching a proof from a CA
+  OCSP server is supplied.  The server URL may be included in the
+  server certificate, if the CA is helpful.
+
+  One failure mode seen was the OCSP Signer cert expiring before the end
+  of validity of the OCSP proof. The checking done by Exim/OpenSSL
+  noted this as invalid overall, but the re-fetch script did not.
+.endd
+
+

 
 
 .section "Configuring an Exim client to use TLS" "SECID185"
 
 
 .section "Configuring an Exim client to use TLS" "SECID185"


@@ -25085,11 +26587,36 @@ if it requests it. If the server is Exim, it will request a certificate only if
 &%tls_verify_hosts%& or &%tls_try_verify_hosts%& matches the client.
 
 If the &%tls_verify_certificates%& option is set on the &(smtp)& transport, it
 &%tls_verify_hosts%& or &%tls_try_verify_hosts%& matches the client.
 
 If the &%tls_verify_certificates%& option is set on the &(smtp)& transport, it

+specifies a collection of expected server certificates.
+.new
+These may be the system default set (depending on library version),
+.wen
+a file or,
+depnding on liibrary version, a directory,

 must name a file or,
 must name a file or,

-for OpenSSL only (not GnuTLS), a directory, that contains a collection of
-expected server certificates. The client verifies the server's certificate
+for OpenSSL only (not GnuTLS), a directory.
+The client verifies the server's certificate

 against this collection, taking into account any revoked certificates that are
 in the list defined by &%tls_crl%&.
 against this collection, taking into account any revoked certificates that are
 in the list defined by &%tls_crl%&.

+Failure to verify fails the TLS connection unless either of the
+&%tls_verify_hosts%& or &%tls_try_verify_hosts%& options are set.
+
+The &%tls_verify_hosts%& and &%tls_try_verify_hosts%& options restrict
+certificate verification to the listed servers.  Verification either must
+or need not succeed respectively.
+
+The &(smtp)& transport has two OCSP-related options:
+&%hosts_require_ocsp%&; a host-list for which a Certificate Status
+is requested and required for the connection to proceed.  The default
+value is empty.
+&%hosts_request_ocsp%&; a host-list for which (additionally)
+a Certificate Status is requested (but not necessarily verified).  The default
+value is "*" meaning that requests are made unless configured
+otherwise.
+
+The host(s) should also be in &%hosts_require_tls%&, and
+&%tls_verify_certificates%& configured for the transport,
+for OCSP to be relevant.

 
 If
 &%tls_require_ciphers%& is set on the &(smtp)& transport, it must contain a
 
 If
 &%tls_require_ciphers%& is set on the &(smtp)& transport, it must contain a


@@ -25110,9 +26637,12 @@ All the TLS options in the &(smtp)& transport are expanded before use, with
 which the client is connected. Forced failure of an expansion causes Exim to
 behave as if the relevant option were unset.
 
 which the client is connected. Forced failure of an expansion causes Exim to
 behave as if the relevant option were unset.
 

-.vindex &$tls_cipher$&
-.vindex &$tls_peerdn$&
-Before an SMTP connection is established, the &$tls_cipher$& and &$tls_peerdn$&
+.vindex &$tls_out_bits$&
+.vindex &$tls_out_cipher$&
+.vindex &$tls_out_peerdn$&
+.vindex &$tls_out_sni$&
+Before an SMTP connection is established, the
+&$tls_out_bits$&, &$tls_out_cipher$&, &$tls_out_peerdn$& and &$tls_out_sni$&

 variables are emptied. (Until the first connection, they contain the values
 that were set when the message was received.) If STARTTLS is subsequently
 successfully obeyed, these variables are set to the relevant values for the
 variables are emptied. (Until the first connection, they contain the values
 that were set when the message was received.) If STARTTLS is subsequently
 successfully obeyed, these variables are set to the relevant values for the


@@ -25120,6 +26650,83 @@ outgoing connection.
 
 
 
 
 
 

+.section "Use of TLS Server Name Indication" "SECTtlssni"
+.cindex "TLS" "Server Name Indication"
+.vindex "&$tls_in_sni$&"
+.oindex "&%tls_in_sni%&"
+With TLS1.0 or above, there is an extension mechanism by which extra
+information can be included at various points in the protocol.  One of these
+extensions, documented in RFC 6066 (and before that RFC 4366) is
+&"Server Name Indication"&, commonly &"SNI"&.  This extension is sent by the
+client in the initial handshake, so that the server can examine the servername
+within and possibly choose to use different certificates and keys (and more)
+for this session.
+
+This is analagous to HTTP's &"Host:"& header, and is the main mechanism by
+which HTTPS-enabled web-sites can be virtual-hosted, many sites to one IP
+address.
+
+With SMTP to MX, there are the same problems here as in choosing the identity
+against which to validate a certificate: you can't rely on insecure DNS to
+provide the identity which you then cryptographically verify.  So this will
+be of limited use in that environment.
+
+With SMTP to Submission, there is a well-defined hostname which clients are
+connecting to and can validate certificates against.  Thus clients &*can*&
+choose to include this information in the TLS negotiation.  If this becomes
+wide-spread, then hosters can choose to present different certificates to
+different clients.  Or even negotiate different cipher suites.
+
+The &%tls_sni%& option on an SMTP transport is an expanded string; the result,
+if not empty, will be sent on a TLS session as part of the handshake.  There's
+nothing more to it.  Choosing a sensible value not derived insecurely is the
+only point of caution.  The &$tls_out_sni$& variable will be set to this string
+for the lifetime of the client connection (including during authentication).
+
+Except during SMTP client sessions, if &$tls_in_sni$& is set then it is a string
+received from a client.
+It can be logged with the &%log_selector%& item &`+tls_sni`&.
+
+If the string &`tls_in_sni`& appears in the main section's &%tls_certificate%&
+option (prior to expansion) then the following options will be re-expanded
+during TLS session handshake, to permit alternative values to be chosen:
+
+.ilist
+.vindex "&%tls_certificate%&"
+&%tls_certificate%&
+.next
+.vindex "&%tls_crl%&"
+&%tls_crl%&
+.next
+.vindex "&%tls_privatekey%&"
+&%tls_privatekey%&
+.next
+.vindex "&%tls_verify_certificates%&"
+&%tls_verify_certificates%&
+.next
+.vindex "&%tls_ocsp_file%&"
+&%tls_ocsp_file%&
+.endlist
+
+Great care should be taken to deal with matters of case, various injection
+attacks in the string (&`../`& or SQL), and ensuring that a valid filename
+can always be referenced; it is important to remember that &$tls_sni$& is
+arbitrary unverified data provided prior to authentication.
+
+The Exim developers are proceeding cautiously and so far no other TLS options
+are re-expanded.
+
+When Exim is built againt OpenSSL, OpenSSL must have been built with support
+for TLS Extensions.  This holds true for OpenSSL 1.0.0+ and 0.9.8+ with
+enable-tlsext in EXTRACONFIGURE.  If you invoke &(openssl s_client -h)& and
+see &`-servername`& in the output, then OpenSSL has support.
+
+When Exim is built against GnuTLS, SNI support is available as of GnuTLS
+0.5.10.  (Its presence predates the current API which Exim uses, so if Exim
+built, then you have SNI support).
+
+
+

 .section "Multiple messages on the same encrypted TCP/IP connection" &&&
          "SECTmulmessam"
 .cindex "multiple SMTP deliveries with TLS"
 .section "Multiple messages on the same encrypted TCP/IP connection" &&&
          "SECTmulmessam"
 .cindex "multiple SMTP deliveries with TLS"


@@ -25190,11 +26797,19 @@ validation to succeed, of course, but if it's not preinstalled, sending the
 root certificate along with the rest makes it available for the user to
 install if the receiving end is a client MUA that can interact with a user.
 
 root certificate along with the rest makes it available for the user to
 install if the receiving end is a client MUA that can interact with a user.
 

+Note that certificates using MD5 are unlikely to work on today's Internet;
+even if your libraries allow loading them for use in Exim when acting as a
+server, increasingly clients will not accept such certificates.  The error
+diagnostics in such a case can be frustratingly vague.
+
+

 
 .section "Self-signed certificates" "SECID187"
 .cindex "certificate" "self-signed"
 You can create a self-signed certificate using the &'req'& command provided
 with OpenSSL, like this:
 
 .section "Self-signed certificates" "SECID187"
 .cindex "certificate" "self-signed"
 You can create a self-signed certificate using the &'req'& command provided
 with OpenSSL, like this:

+. ==== Do not shorten the duration here without reading and considering
+. ==== the text below.  Please leave it at 9999 days.

 .code
 openssl req -x509 -newkey rsa:1024 -keyout file1 -out file2 \
             -days 9999 -nodes
 .code
 openssl req -x509 -newkey rsa:1024 -keyout file1 -out file2 \
             -days 9999 -nodes


@@ -25207,6 +26822,22 @@ that you are prompted for, and any use that is made of the key causes more
 prompting for the passphrase. This is not helpful if you are going to use
 this certificate and key in an MTA, where prompting is not possible.
 
 prompting for the passphrase. This is not helpful if you are going to use
 this certificate and key in an MTA, where prompting is not possible.
 

+. ==== I expect to still be working 26 years from now.  The less technical
+. ==== debt I create, in terms of storing up trouble for my later years, the
+. ==== happier I will be then.  We really have reached the point where we
+. ==== should start, at the very least, provoking thought and making folks
+. ==== pause before proceeding, instead of leaving all the fixes until two
+. ==== years before 2^31 seconds after the 1970 Unix epoch.
+. ==== -pdp, 2012
+NB: we are now past the point where 9999 days takes us past the 32-bit Unix
+epoch.  If your system uses unsigned time_t (most do) and is 32-bit, then
+the above command might produce a date in the past.  Think carefully about
+the lifetime of the systems you're deploying, and either reduce the duration
+of the certificate or reconsider your platform deployment.  (At time of
+writing, reducing the duration is the most likely choice, but the inexorable
+progression of time takes us steadily towards an era where this will not
+be a sensible resolution).
+

 A self-signed certificate made in this way is sufficient for testing, and
 may be adequate for all your requirements if you are mainly interested in
 encrypting transfers, and not in secure identification.
 A self-signed certificate made in this way is sufficient for testing, and
 may be adequate for all your requirements if you are mainly interested in
 encrypting transfers, and not in secure identification.


@@ -25283,6 +26914,7 @@ options in the main part of the configuration. These options are:
 .cindex "SMTP" "connection, ACL for"
 .cindex "non-SMTP messages" "ACLs for"
 .cindex "MIME content scanning" "ACL for"
 .cindex "SMTP" "connection, ACL for"
 .cindex "non-SMTP messages" "ACLs for"
 .cindex "MIME content scanning" "ACL for"

+.cindex "PRDR" "ACL for"

 
 .table2 140pt
 .irow &%acl_not_smtp%&         "ACL for non-SMTP messages"
 
 .table2 140pt
 .irow &%acl_not_smtp%&         "ACL for non-SMTP messages"


@@ -25291,6 +26923,7 @@ options in the main part of the configuration. These options are:
 .irow &%acl_smtp_auth%&        "ACL for AUTH"
 .irow &%acl_smtp_connect%&     "ACL for start of SMTP connection"
 .irow &%acl_smtp_data%&        "ACL after DATA is complete"
 .irow &%acl_smtp_auth%&        "ACL for AUTH"
 .irow &%acl_smtp_connect%&     "ACL for start of SMTP connection"
 .irow &%acl_smtp_data%&        "ACL after DATA is complete"

+.irow &%acl_smtp_data_prdr%&   "ACL for each recipient, after DATA is complete"

 .irow &%acl_smtp_etrn%&        "ACL for ETRN"
 .irow &%acl_smtp_expn%&        "ACL for EXPN"
 .irow &%acl_smtp_helo%&        "ACL for HELO or EHLO"
 .irow &%acl_smtp_etrn%&        "ACL for ETRN"
 .irow &%acl_smtp_expn%&        "ACL for EXPN"
 .irow &%acl_smtp_helo%&        "ACL for HELO or EHLO"


@@ -25405,6 +27038,10 @@ before or after the data) correctly &-- they keep the message on their queues
 and try again later, but that is their problem, though it does waste some of
 your resources.
 
 and try again later, but that is their problem, though it does waste some of
 your resources.
 

+The &%acl_smtp_data%& ACL is run after
+the &%acl_smtp_data_prdr%&,
+the &%acl_smtp_dkim%&
+and the &%acl_smtp_mime%& ACLs.

 
 .section "The SMTP DKIM ACL" "SECTDKIMACL"
 The &%acl_smtp_dkim%& ACL is available only when Exim is compiled with DKIM support
 
 .section "The SMTP DKIM ACL" "SECTDKIMACL"
 The &%acl_smtp_dkim%& ACL is available only when Exim is compiled with DKIM support


@@ -25414,13 +27051,49 @@ The ACL test specified by &%acl_smtp_dkim%& happens after a message has been
 received, and is executed for each DKIM signature found in a message.  If not
 otherwise specified, the default action is to accept.
 
 received, and is executed for each DKIM signature found in a message.  If not
 otherwise specified, the default action is to accept.
 

-For details on the operation of DKIM, see chapter &<<CHID12>>&.
+This ACL is evaluated before &%acl_smtp_mime%& and &%acl_smtp_data%&.
+
+For details on the operation of DKIM, see chapter &<<CHAPdkim>>&.

 
 
 .section "The SMTP MIME ACL" "SECID194"
 The &%acl_smtp_mime%& option is available only when Exim is compiled with the
 content-scanning extension. For details, see chapter &<<CHAPexiscan>>&.
 
 
 
 .section "The SMTP MIME ACL" "SECID194"
 The &%acl_smtp_mime%& option is available only when Exim is compiled with the
 content-scanning extension. For details, see chapter &<<CHAPexiscan>>&.
 

+This ACL is evaluated after &%acl_smtp_dkim%& but before &%acl_smtp_data%&.
+
+
+.section "The SMTP PRDR ACL" "SECTPRDRACL"
+.cindex "PRDR" "ACL for"
+.oindex "&%prdr_enable%&"
+The &%acl_smtp_data_prdr%& ACL is available only when Exim is compiled
+with PRDR support enabled (which is the default).
+It becomes active only when the PRDR feature is negotiated between
+client and server for a message, and more than one recipient
+has been accepted.
+
+The ACL test specfied by &%acl_smtp_data_prdr%& happens after a message
+has been recieved, and is executed once for each recipient of the message
+with &$local_part$& and &$domain$& valid.
+The test may accept, defer or deny for inividual recipients.
+The &%acl_smtp_data%& will still be called after this ACL and
+can reject the message overall, even if this ACL has accepted it
+for some or all recipients.
+
+PRDR may be used to support per-user content filtering.  Without it
+one must defer any recipient after the first that has a different
+content-filter configuration.  With PRDR, the RCPT-time check
+for this can be disabled when the MAIL-time $smtp_command included
+"PRDR".  Any required difference in behaviour of the main DATA-time
+ACL should however depend on the PRDR-time ACL having run, as Exim
+will avoid doing so in some situations (eg.  single-recipient mails).
+
+See also the &%prdr_enable%& global option
+and the &%hosts_try_prdr%& smtp transport option.
+
+This ACL is evaluated after &%acl_smtp_dkim%& but before &%acl_smtp_data%&.
+If the ACL is not defined, processing completes as if
+the feature was not requested by the client.

 
 .section "The QUIT ACL" "SECTQUITACL"
 .cindex "QUIT, ACL for"
 
 .section "The QUIT ACL" "SECTQUITACL"
 .cindex "QUIT, ACL for"


@@ -25451,7 +27124,7 @@ connection is closed. In these special cases, the QUIT ACL does not run.
 .section "The not-QUIT ACL" "SECTNOTQUITACL"
 .vindex &$acl_smtp_notquit$&
 The not-QUIT ACL, specified by &%acl_smtp_notquit%&, is run in most cases when
 .section "The not-QUIT ACL" "SECTNOTQUITACL"
 .vindex &$acl_smtp_notquit$&
 The not-QUIT ACL, specified by &%acl_smtp_notquit%&, is run in most cases when

-an SMTP session ends without sending QUIT. However, when Exim itself is is bad
+an SMTP session ends without sending QUIT. However, when Exim itself is in bad

 trouble, such as being unable to write to its log files, this ACL is not run,
 because it might try to do things (such as write to log files) that make the
 situation even worse.
 trouble, such as being unable to write to its log files, this ACL is not run,
 because it might try to do things (such as write to log files) that make the
 situation even worse.


@@ -25805,8 +27478,8 @@ duplicates to be written, use the &%logwrite%& modifier instead.
 
 If &%log_message%& is not present, a &%warn%& verb just checks its conditions
 and obeys any &"immediate"& modifiers (such as &%control%&, &%set%&,
 
 If &%log_message%& is not present, a &%warn%& verb just checks its conditions
 and obeys any &"immediate"& modifiers (such as &%control%&, &%set%&,

-&%logwrite%&, and &%add_header%&) that appear before the first failing
-condition. There is more about adding header lines in section
+&%logwrite%&, &%add_header%&, and &%remove_header%&) that appear before the
+first failing condition. There is more about adding header lines in section

 &<<SECTaddheadacl>>&.
 
 If any condition on a &%warn%& statement cannot be completed (that is, there is
 &<<SECTaddheadacl>>&.
 
 If any condition on a &%warn%& statement cannot be completed (that is, there is


@@ -25924,7 +27597,7 @@ others specify text for messages that are used when access is denied or a
 warning is generated. The &%control%& modifier affects the way an incoming
 message is handled.
 
 warning is generated. The &%control%& modifier affects the way an incoming
 message is handled.
 

-The positioning of the modifiers in an ACL statement important, because the
+The positioning of the modifiers in an ACL statement is important, because the

 processing of a verb ceases as soon as its outcome is known. Only those
 modifiers that have already been encountered will take effect. For example,
 consider this use of the &%message%& modifier:
 processing of a verb ceases as soon as its outcome is known. Only those
 modifiers that have already been encountered will take effect. For example,
 consider this use of the &%message%& modifier:


@@ -26045,12 +27718,12 @@ If you want to apply a control unconditionally, you can use it with a
 .vitem &*delay*&&~=&~<&'time'&>
 .cindex "&%delay%& ACL modifier"
 .oindex "&%-bh%&"
 .vitem &*delay*&&~=&~<&'time'&>
 .cindex "&%delay%& ACL modifier"
 .oindex "&%-bh%&"

-This modifier may appear in any ACL. It causes Exim to wait for the time
-interval before proceeding. However, when testing Exim using the &%-bh%&
-option, the delay is not actually imposed (an appropriate message is output
-instead). The time is given in the usual Exim notation, and the delay happens
-as soon as the modifier is processed. In an SMTP session, pending output is
-flushed before the delay is imposed.
+This modifier may appear in any ACL except notquit. It causes Exim to wait for
+the time interval before proceeding. However, when testing Exim using the
+&%-bh%& option, the delay is not actually imposed (an appropriate message is
+output instead). The time is given in the usual Exim notation, and the delay
+happens as soon as the modifier is processed. In an SMTP session, pending
+output is flushed before the delay is imposed.

 
 Like &%control%&, &%delay%& can be used with &%accept%& or &%deny%&, for
 example:
 
 Like &%control%&, &%delay%& can be used with &%accept%& or &%deny%&, for
 example:


@@ -26097,7 +27770,7 @@ confusing to some people, so the use of &%endpass%& is no longer recommended as
 This modifier sets up a message that is used as part of the log message if the
 ACL denies access or a &%warn%& statement's conditions are true. For example:
 .code
 This modifier sets up a message that is used as part of the log message if the
 ACL denies access or a &%warn%& statement's conditions are true. For example:
 .code

-require log_message = wrong cipher suite $tls_cipher
+require log_message = wrong cipher suite $tls_in_cipher

         encrypted   = DES-CBC3-SHA
 .endd
 &%log_message%& is also used when recipients are discarded by &%discard%&. For
         encrypted   = DES-CBC3-SHA
 .endd
 &%log_message%& is also used when recipients are discarded by &%discard%&. For


@@ -26231,6 +27904,9 @@ anyway. If the message contains newlines, this gives rise to a multi-line SMTP
 response.
 
 .vindex "&$acl_verify_message$&"
 response.
 
 .vindex "&$acl_verify_message$&"

+For ACLs that are called by an &%acl =%& ACL condition, the message is
+stored in &$acl_verify_message$&, from which the calling ACL may use it.
+

 If &%message%& is used on a statement that verifies an address, the message
 specified overrides any message that is generated by the verification process.
 However, the original message is available in the variable
 If &%message%& is used on a statement that verifies an address, the message
 specified overrides any message that is generated by the verification process.
 However, the original message is available in the variable


@@ -26248,13 +27924,33 @@ all the conditions are true, wherever it appears in an ACL command, whereas
 effect.
 
 
 effect.
 
 

+.vitem &*remove_header*&&~=&~<&'text'&>
+This modifier specifies one or more header names in a colon-separated list
+ that are to be removed from an incoming message, assuming, of course, that
+the message is ultimately accepted. For details, see section &<<SECTremoveheadacl>>&.
+
+

 .vitem &*set*&&~<&'acl_name'&>&~=&~<&'value'&>
 .cindex "&%set%& ACL modifier"
 This modifier puts a value into one of the ACL variables (see section
 &<<SECTaclvariables>>&).
 .vitem &*set*&&~<&'acl_name'&>&~=&~<&'value'&>
 .cindex "&%set%& ACL modifier"
 This modifier puts a value into one of the ACL variables (see section
 &<<SECTaclvariables>>&).

-.endlist

 
 
 
 

+.vitem &*udpsend*&&~=&~<&'parameters'&>
+This modifier sends a UDP packet, for purposes such as statistics
+collection or behaviour monitoring. The parameters are expanded, and
+the result of the expansion must be a colon-separated list consisting
+of a destination server, port number, and the packet contents. The
+server can be specified as a host name or IPv4 or IPv6 address. The
+separator can be changed with the usual angle bracket syntax. For
+example, you might want to collect information on which hosts connect
+when:
+.code
+udpsend = <; 2001:dB8::dead:beef ; 1234 ;\
+             $tod_zulu $sender_host_address
+.endd
+.endlist
+

 
 
 
 
 
 


@@ -26314,6 +28010,48 @@ Notice that we put back the lower cased version afterwards, assuming that
 is what is wanted for subsequent tests.
 
 
 is what is wanted for subsequent tests.
 
 

+.vitem &*control&~=&~cutthrough_delivery*&
+.cindex "&ACL;" "cutthrough routing"
+.cindex "cutthrough" "requesting"
+This option requests delivery be attempted while the item is being received.
+
+The option is usable in the RCPT ACL.
+If enabled for a message recieved via smtp and routed to an smtp transport,
+and only one transport, interface, destination host and port combination
+is used for all recipients of the message,
+then the delivery connection is made while the receiving connection is open
+and data is copied from one to the other.
+
+An attempt to set this option for any recipient but the first
+for a mail will be quietly ignored.
+If a recipient-verify callout connection is subsequently
+requested in the same ACL it is held open and used for
+any subsequent receipients and the data,
+otherwise one is made after the initial RCPT ACL completes.
+
+Note that routers are used in verify mode,
+and cannot depend on content of received headers.
+Note also that headers cannot be
+modified by any of the post-data ACLs (DATA, MIME and DKIM).
+Headers may be modified by routers (subject to the above) and transports.
+
+Cutthrough delivery is not supported via transport-filters or when DKIM signing
+of outgoing messages is done, because it sends data to the ultimate destination
+before the entire message has been received from the source.
+It is not supported for messages recieved with the SMTP PRDR option in use.
+
+Should the ultimate destination system positively accept or reject the mail,
+a corresponding indication is given to the source system and nothing is queued.
+If there is a temporary error the item is queued for later delivery in the
+usual fashion. If the item is successfully delivered in cutthrough mode
+the delivery log lines are tagged with ">>" rather than "=>" and appear
+before the acceptance "<=" line.
+
+Delivery in this mode avoids the generation of a bounce mail to a
+(possibly faked)
+sender when the destination system is doing content-scan based rejection.
+
+

 .vitem &*control&~=&~debug/*&<&'options'&>
 .cindex "&ACL;" "enabling debug logging"
 .cindex "debugging" "enabling from an ACL"
 .vitem &*control&~=&~debug/*&<&'options'&>
 .cindex "&ACL;" "enabling debug logging"
 .cindex "debugging" "enabling from an ACL"


@@ -26332,6 +28070,30 @@ contexts):
 .endd
 
 
 .endd
 
 

+.vitem &*control&~=&~dkim_disable_verify*&
+.cindex "disable DKIM verify"
+.cindex "DKIM" "disable verify"
+This control turns off DKIM verification processing entirely.  For details on
+the operation and configuration of DKIM, see chapter &<<CHAPdkim>>&.
+
+
+.vitem &*control&~=&~dscp/*&<&'value'&>
+.cindex "&ACL;" "setting DSCP value"
+.cindex "DSCP" "inbound"
+This option causes the DSCP value associated with the socket for the inbound
+connection to be adjusted to a given value, given as one of a number of fixed
+strings or to numeric value.
+The &%-bI:dscp%& option may be used to ask Exim which names it knows of.
+Common values include &`throughput`&, &`mincost`&, and on newer systems
+&`ef`&, &`af41`&, etc.  Numeric values may be in the range 0 to 0x3F.
+
+The outbound packets from Exim will be marked with this value in the header
+(for IPv4, the TOS field; for IPv6, the TCLASS field); there is no guarantee
+that these values will have any effect, not be stripped by networking
+equipment, or do much of anything without cooperation with your Network
+Engineer and those of all network operators between the source and destination.
+
+

 .vitem &*control&~=&~enforce_sync*& &&&
        &*control&~=&~no_enforce_sync*&
 .cindex "SMTP" "synchronization checking"
 .vitem &*control&~=&~enforce_sync*& &&&
        &*control&~=&~no_enforce_sync*&
 .cindex "SMTP" "synchronization checking"


@@ -26522,7 +28284,7 @@ Remotely submitted, fixups applied: use &`control = submission`&.
 .section "Adding header lines in ACLs" "SECTaddheadacl"
 .cindex "header lines" "adding in an ACL"
 .cindex "header lines" "position of added lines"
 .section "Adding header lines in ACLs" "SECTaddheadacl"
 .cindex "header lines" "adding in an ACL"
 .cindex "header lines" "position of added lines"

-.cindex "&%message%& ACL modifier"
+.cindex "&%add_header%& ACL modifier"

 The &%add_header%& modifier can be used to add one or more extra header lines
 to an incoming message, as in this example:
 .code
 The &%add_header%& modifier can be used to add one or more extra header lines
 to an incoming message, as in this example:
 .code


@@ -26531,13 +28293,18 @@ warn dnslists = sbl.spamhaus.org : \
      add_header = X-blacklisted-at: $dnslist_domain
 .endd
 The &%add_header%& modifier is permitted in the MAIL, RCPT, PREDATA, DATA,
      add_header = X-blacklisted-at: $dnslist_domain
 .endd
 The &%add_header%& modifier is permitted in the MAIL, RCPT, PREDATA, DATA,

-MIME, and non-SMTP ACLs (in other words, those that are concerned with
+MIME, DKIM, and non-SMTP ACLs (in other words, those that are concerned with

 receiving a message). The message must ultimately be accepted for
 &%add_header%& to have any significant effect. You can use &%add_header%& with
 any ACL verb, including &%deny%& (though this is potentially useful only in a
 RCPT ACL).
 
 receiving a message). The message must ultimately be accepted for
 &%add_header%& to have any significant effect. You can use &%add_header%& with
 any ACL verb, including &%deny%& (though this is potentially useful only in a
 RCPT ACL).
 

-If the data for the &%add_header%& modifier contains one or more newlines that
+Headers will not be added to the message if the modifier is used in
+DATA, MIME or DKIM ACLs for messages delivered by cutthrough routing.
+
+Leading and trailing newlines are removed from
+the data for the &%add_header%& modifier; if it then
+contains one or more newlines that

 are not followed by a space or a tab, it is assumed to contain multiple header
 lines. Each one is checked for valid syntax; &`X-ACL-Warn:`& is added to the
 front of any line that is not a valid header line.
 are not followed by a space or a tab, it is assumed to contain multiple header
 lines. Each one is checked for valid syntax; &`X-ACL-Warn:`& is added to the
 front of any line that is not a valid header line.


@@ -26555,7 +28322,9 @@ message is rejected after DATA or by the non-SMTP ACL, all added header lines
 are included in the entry that is written to the reject log.
 
 .cindex "header lines" "added; visibility of"
 are included in the entry that is written to the reject log.
 
 .cindex "header lines" "added; visibility of"

-Header lines are not visible in string expansions until they are added to the
+Header lines are not visible in string expansions
+of message headers
+until they are added to the

 message. It follows that header lines defined in the MAIL, RCPT, and predata
 ACLs are not visible until the DATA ACL and MIME ACLs are run. Similarly,
 header lines that are added by the DATA or MIME ACLs are not visible in those
 message. It follows that header lines defined in the MAIL, RCPT, and predata
 ACLs are not visible until the DATA ACL and MIME ACLs are run. Similarly,
 header lines that are added by the DATA or MIME ACLs are not visible in those


@@ -26564,7 +28333,9 @@ passing data between (for example) the MAIL and RCPT ACLs. If you want to do
 this, you can use ACL variables, as described in section
 &<<SECTaclvariables>>&.
 
 this, you can use ACL variables, as described in section
 &<<SECTaclvariables>>&.
 

-The &%add_header%& modifier acts immediately it is encountered during the
+The list of headers yet to be added is given by the &%$headers_added%& variable.
+
+The &%add_header%& modifier acts immediately as it is encountered during the

 processing of an ACL. Notice the difference between these two cases:
 .display
 &`accept add_header = ADDED: some text`&
 processing of an ACL. Notice the difference between these two cases:
 .display
 &`accept add_header = ADDED: some text`&


@@ -26613,10 +28384,83 @@ system filter or in a router or transport.
 
 
 
 
 
 

+.section "Removing header lines in ACLs" "SECTremoveheadacl"
+.cindex "header lines" "removing in an ACL"
+.cindex "header lines" "position of removed lines"
+.cindex "&%remove_header%& ACL modifier"
+The &%remove_header%& modifier can be used to remove one or more header lines
+from an incoming message, as in this example:
+.code
+warn   message        = Remove internal headers
+       remove_header  = x-route-mail1 : x-route-mail2
+.endd
+The &%remove_header%& modifier is permitted in the MAIL, RCPT, PREDATA, DATA,
+MIME, DKIM, and non-SMTP ACLs (in other words, those that are concerned with
+receiving a message). The message must ultimately be accepted for
+&%remove_header%& to have any significant effect. You can use &%remove_header%&
+with any ACL verb, including &%deny%&, though this is really not useful for
+any verb that doesn't result in a delivered message.
+
+Headers will not be removed to the message if the modifier is used in
+DATA, MIME or DKIM ACLs for messages delivered by cutthrough routing.
+
+More than one header can be removed at the same time by using a colon separated
+list of header names. The header matching is case insensitive. Wildcards are
+not permitted, nor is list expansion performed, so you cannot use hostlists to
+create a list of headers, however both connection and message variable expansion
+are performed (&%$acl_c_*%& and &%$acl_m_*%&), illustrated in this example:
+.code
+warn   hosts           = +internal_hosts
+       set acl_c_ihdrs = x-route-mail1 : x-route-mail2
+warn   message         = Remove internal headers
+       remove_header   = $acl_c_ihdrs
+.endd
+Removed header lines are accumulated during the MAIL, RCPT, and predata ACLs.
+They are removed from the message before processing the DATA and MIME ACLs.
+There is no harm in attempting to remove the same header twice nor is removing
+a non-existent header. Further header lines to be removed may be accumulated
+during the DATA and MIME ACLs, after which they are removed from the message,
+if present. In the case of non-SMTP messages, headers to be removed are
+accumulated during the non-SMTP ACLs, and are removed from the message after
+all the ACLs have run. If a message is rejected after DATA or by the non-SMTP
+ACL, there really is no effect because there is no logging of what headers
+would have been removed.
+
+.cindex "header lines" "removed; visibility of"
+Header lines are not visible in string expansions until the DATA phase when it
+is received. Any header lines removed in the MAIL, RCPT, and predata ACLs are
+not visible in the DATA ACL and MIME ACLs. Similarly, header lines that are
+removed by the DATA or MIME ACLs are still visible in those ACLs. Because of
+this restriction, you cannot use header lines as a way of controlling data
+passed between (for example) the MAIL and RCPT ACLs. If you want to do this,
+you should instead use ACL variables, as described in section
+&<<SECTaclvariables>>&.
+
+The &%remove_header%& modifier acts immediately as it is encountered during the
+processing of an ACL. Notice the difference between these two cases:
+.display
+&`accept remove_header = X-Internal`&
+&`       `&<&'some condition'&>
+
+&`accept `&<&'some condition'&>
+&`       remove_header = X-Internal`&
+.endd
+In the first case, the header line is always removed, whether or not the
+condition is true. In the second case, the header line is removed only if the
+condition is true. Multiple occurrences of &%remove_header%& may occur in the
+same ACL statement. All those that are encountered before a condition fails
+are honoured.
+
+&*Warning*&: This facility currently applies only to header lines that are
+present during ACL processing. It does NOT remove header lines that are added
+in a system filter or in a router or transport.
+
+
+

 
 .section "ACL conditions" "SECTaclconditions"
 .cindex "&ACL;" "conditions; list of"
 
 .section "ACL conditions" "SECTaclconditions"
 .cindex "&ACL;" "conditions; list of"

-Some of conditions listed in this section are available only when Exim is
+Some of the conditions listed in this section are available only when Exim is

 compiled with the content-scanning extension. They are included here briefly
 for completeness. More detailed descriptions can be found in the discussion on
 content scanning in chapter &<<CHAPexiscan>>&.
 compiled with the content-scanning extension. They are included here briefly
 for completeness. More detailed descriptions can be found in the discussion on
 content scanning in chapter &<<CHAPexiscan>>&.


@@ -26634,6 +28478,7 @@ The conditions are as follows:
 .vitem &*acl&~=&~*&<&'name&~of&~acl&~or&~ACL&~string&~or&~file&~name&~'&>
 .cindex "&ACL;" "nested"
 .cindex "&ACL;" "indirect"
 .vitem &*acl&~=&~*&<&'name&~of&~acl&~or&~ACL&~string&~or&~file&~name&~'&>
 .cindex "&ACL;" "nested"
 .cindex "&ACL;" "indirect"

+.cindex "&ACL;" "arguments"

 .cindex "&%acl%& ACL condition"
 The possible values of the argument are the same as for the
 &%acl_smtp_%&&'xxx'& options. The named or inline ACL is run. If it returns
 .cindex "&%acl%& ACL condition"
 The possible values of the argument are the same as for the
 &%acl_smtp_%&&'xxx'& options. The named or inline ACL is run. If it returns


@@ -26643,6 +28488,14 @@ condition is on a &%warn%& verb. In that case, a &"defer"& return makes the
 condition false. This means that further processing of the &%warn%& verb
 ceases, but processing of the ACL continues.
 
 condition false. This means that further processing of the &%warn%& verb
 ceases, but processing of the ACL continues.
 

+If the argument is a named ACL, up to nine space-separated optional values
+can be appended; they appear within the called ACL in $acl_arg1 to $acl_arg9,
+and $acl_narg is set to the count of values.
+Previous values of these variables are restored after the call returns.
+The name and values are expanded separately.
+Note that spaces in complex expansions which are used as arguments
+will act as argument separators.
+

 If the nested &%acl%& returns &"drop"& and the outer condition denies access,
 the connection is dropped. If it returns &"discard"&, the verb must be
 &%accept%& or &%discard%&, and the action is taken immediately &-- no further
 If the nested &%acl%& returns &"drop"& and the outer condition denies access,
 the connection is dropped. If it returns &"discard"&, the verb must be
 &%accept%& or &%discard%&, and the action is taken immediately &-- no further


@@ -26731,7 +28584,7 @@ encrypted = *
 .endd
 
 
 .endd
 
 

-.vitem &*hosts&~=&~*&<&'&~host&~list'&>
+.vitem &*hosts&~=&~*&<&'host&~list'&>

 .cindex "&%hosts%& ACL condition"
 .cindex "host" "ACL checking"
 .cindex "&ACL;" "testing the client host"
 .cindex "&%hosts%& ACL condition"
 .cindex "host" "ACL checking"
 .cindex "&ACL;" "testing the client host"


@@ -26873,6 +28726,21 @@ This condition checks whether the sending host (the client) is authorized to
 send email. Details of how this works are given in section
 &<<SECTverifyCSA>>&.
 
 send email. Details of how this works are given in section
 &<<SECTverifyCSA>>&.
 

+.vitem &*verify&~=&~header_names_ascii*&
+.cindex "&%verify%& ACL condition"
+.cindex "&ACL;" "verifying header names only ASCII"
+.cindex "header lines" "verifying header names only ASCII"
+.cindex "verifying" "header names only ASCII"
+This condition is relevant only in an ACL that is run after a message has been
+received, that is, in an ACL specified by &%acl_smtp_data%& or
+&%acl_not_smtp%&.  It checks all header names (not the content) to make sure
+there are no non-ASCII characters, also excluding control characters.  The
+allowable characters are decimal ASCII values 33 through 126.
+
+Exim itself will handle headers with non-ASCII characters, but it can cause
+problems for downstream applications, so this option will allow their
+detection and rejection in the DATA ACL's.
+

 .vitem &*verify&~=&~header_sender/*&<&'options'&>
 .cindex "&%verify%& ACL condition"
 .cindex "&ACL;" "verifying sender in the header"
 .vitem &*verify&~=&~header_sender/*&<&'options'&>
 .cindex "&%verify%& ACL condition"
 .cindex "&ACL;" "verifying sender in the header"


@@ -26968,7 +28836,7 @@ verified is redirected to a single address, verification continues with the new
 address, and in that case, the subsequent value of &$address_data$& is the
 value for the child address.
 
 address, and in that case, the subsequent value of &$address_data$& is the
 value for the child address.
 

-.vitem &*verify&~=&~reverse_host_lookup*&
+.vitem &*verify&~=&~reverse_host_lookup/*&<&'options'&>

 .cindex "&%verify%& ACL condition"
 .cindex "&ACL;" "verifying host reverse lookup"
 .cindex "host" "verifying reverse lookup"
 .cindex "&%verify%& ACL condition"
 .cindex "&ACL;" "verifying host reverse lookup"
 .cindex "host" "verifying reverse lookup"


@@ -26979,6 +28847,9 @@ Verification ensures that the host name obtained from a reverse DNS lookup, or
 one of its aliases, does, when it is itself looked up in the DNS, yield the
 original IP address.
 
 one of its aliases, does, when it is itself looked up in the DNS, yield the
 original IP address.
 

+There is one possible option, &`defer_ok`&.  If this is present and a
+DNS operation returns a temporary error, the verify condition succeeds.
+

 If this condition is used for a locally generated message (that is, when there
 is no client host involved), it always succeeds.
 
 If this condition is used for a locally generated message (that is, when there
 is no client host involved), it always succeeds.
 


@@ -27391,7 +29262,7 @@ dnslists = a.b.c!&0.0.0.1
 If the DNS lookup yields both 127.0.0.1 and 127.0.0.2, the condition is
 false because 127.0.0.1 matches.
 .next
 If the DNS lookup yields both 127.0.0.1 and 127.0.0.2, the condition is
 false because 127.0.0.1 matches.
 .next

-If &`!==`& or &`!=&&`& is used, the condition is true there is at least one
+If &`!==`& or &`!=&&`& is used, the condition is true if there is at least one

 looked up IP address that does not match. Consider:
 .code
 dnslists = a.b.c!=&0.0.0.1
 looked up IP address that does not match. Consider:
 .code
 dnslists = a.b.c!=&0.0.0.1


@@ -27484,6 +29355,13 @@ deny   condition = ${if isip4{$sender_host_address}}
        dnslists  = some.list.example
 .endd
 
        dnslists  = some.list.example
 .endd
 

+If an explicit key is being used for a DNS lookup and it may be an IPv6
+address you should specify alternate list separators for both the outer
+(DNS list name) list and inner (lookup keys) list:
+.code
+       dnslists = <; dnsbl.example.com/<|$acl_m_addrslist
+.endd
+

 .section "Rate limiting incoming messages" "SECTratelimiting"
 .cindex "rate limiting" "client sending"
 .cindex "limiting client sending rates"
 .section "Rate limiting incoming messages" "SECTratelimiting"
 .cindex "rate limiting" "client sending"
 .cindex "limiting client sending rates"


@@ -27615,14 +29493,14 @@ in the MAIL ACL. Subsequent connections from the same client will check this
 new rate.
 .code
 acl_check_connect:
 new rate.
 .code
 acl_check_connect:

-  deny ratelimit = 100 / 5m / readonly
-       log_message = RATE CHECK: $sender_rate/$sender_rate_period \
-                     (max $sender_rate_limit)
+ deny ratelimit = 100 / 5m / readonly
+    log_message = RATE CHECK: $sender_rate/$sender_rate_period \
+                  (max $sender_rate_limit)

 # ...
 acl_check_mail:
 # ...
 acl_check_mail:

-  warn ratelimit = 100 / 5m / strict
-       log_message  = RATE UPDATE: $sender_rate/$sender_rate_period \
-                      (max $sender_rate_limit)
+ warn ratelimit = 100 / 5m / strict
+    log_message = RATE UPDATE: $sender_rate/$sender_rate_period \
+                  (max $sender_rate_limit)

 .endd
 
 If Exim encounters multiple &%ratelimit%& conditions with the same key when
 .endd
 
 If Exim encounters multiple &%ratelimit%& conditions with the same key when


@@ -27865,6 +29743,7 @@ router that does not set up hosts routes to an &(smtp)& transport with a
 &%hosts%& setting, the transport's hosts are used. If an &(smtp)& transport has
 &%hosts_override%& set, its hosts are always used, whether or not the router
 supplies a host list.
 &%hosts%& setting, the transport's hosts are used. If an &(smtp)& transport has
 &%hosts_override%& set, its hosts are always used, whether or not the router
 supplies a host list.

+Callouts are only supported on &(smtp)& transports.

 
 The port that is used is taken from the transport, if it is specified and is a
 remote transport. (For routers that do verification only, no transport need be
 
 The port that is used is taken from the transport, if it is specified and is a
 remote transport. (For routers that do verification only, no transport need be


@@ -27886,6 +29765,9 @@ following SMTP commands are sent:
 LHLO is used instead of HELO if the transport's &%protocol%& option is
 set to &"lmtp"&.
 
 LHLO is used instead of HELO if the transport's &%protocol%& option is
 set to &"lmtp"&.
 

+The callout may use EHLO, AUTH and/or STARTTLS given appropriate option
+settings.
+

 A recipient callout check is similar. By default, it also uses an empty address
 for the sender. This default is chosen because most hosts do not make use of
 the sender address when verifying a recipient. Using the same address means
 A recipient callout check is similar. By default, it also uses an empty address
 for the sender. This default is chosen because most hosts do not make use of
 the sender address when verifying a recipient. Using the same address means


@@ -28401,16 +30283,16 @@ Suppose your LAN is 192.168.45.0/24.
 
 In the main part of the configuration, you put the following definitions:
 .code
 
 In the main part of the configuration, you put the following definitions:
 .code

-domainlist local_domains = my.dom1.example : my.dom2.example
-domainlist relay_domains = friend1.example : friend2.example
-hostlist   relay_hosts   = 192.168.45.0/24
+domainlist local_domains    = my.dom1.example : my.dom2.example
+domainlist relay_to_domains = friend1.example : friend2.example
+hostlist   relay_from_hosts = 192.168.45.0/24

 .endd
 Now you can use these definitions in the ACL that is run for every RCPT
 command:
 .code
 acl_check_rcpt:
 .endd
 Now you can use these definitions in the ACL that is run for every RCPT
 command:
 .code
 acl_check_rcpt:

-  accept domains = +local_domains : +relay_domains
-  accept hosts   = +relay_hosts
+  accept domains = +local_domains : +relay_to_domains
+  accept hosts   = +relay_from_hosts

 .endd
 The first statement accepts any RCPT command that contains an address in
 the local or relay domains. For any other domain, control passes to the second
 .endd
 The first statement accepts any RCPT command that contains an address in
 the local or relay domains. For any other domain, control passes to the second


@@ -28515,10 +30397,14 @@ It supports a &"generic"& interface to scanners called via the shell, and
 specialized interfaces for &"daemon"& type virus scanners, which are resident
 in memory and thus are much faster.
 
 specialized interfaces for &"daemon"& type virus scanners, which are resident
 in memory and thus are much faster.
 

+.new
+A timeout of 2 minutes is applied to a scanner call (by default);
+if it expires then a defer action is taken.
+.wen

 
 .oindex "&%av_scanner%&"
 
 .oindex "&%av_scanner%&"

-You can set the &%av_scanner%& option in first part of the Exim configuration
-file to specify which scanner to use, together with any additional options that
+You can set the &%av_scanner%& option in the main part of the configuration
+to specify which scanner to use, together with any additional options that

 are needed. The basic syntax is as follows:
 .display
 &`av_scanner = <`&&'scanner-type'&&`>:<`&&'option1'&&`>:<`&&'option2'&&`>:[...]`&
 are needed. The basic syntax is as follows:
 .display
 &`av_scanner = <`&&'scanner-type'&&`>:<`&&'option1'&&`>:<`&&'option2'&&`>:[...]`&


@@ -28528,9 +30414,46 @@ If you do not set &%av_scanner%&, it defaults to
 av_scanner = sophie:/var/run/sophie
 .endd
 If the value of &%av_scanner%& starts with a dollar character, it is expanded
 av_scanner = sophie:/var/run/sophie
 .endd
 If the value of &%av_scanner%& starts with a dollar character, it is expanded

-before use. The following scanner types are supported in this release:
+before use.
+The usual list-parsing of the content (see &<<SECTlistconstruct>>&) applies.
+The following scanner types are supported in this release:

 
 .vlist
 
 .vlist

+.new
+.vitem &%avast%&
+.cindex "virus scanners" "avast"
+This is the scanner daemon of Avast. It has been tested with Avast Core
+Security (currenty at version 1.1.7).
+You can get a trial version at &url(http://www.avast.com) or for Linux
+at &url(http://www.avast.com/linux-server-antivirus).
+This scanner type takes one option,
+which can be either a full path to a UNIX socket,
+or host and port specifiers separated by white space.
+The host may be a name or an IP address; the port is either a
+single number or a pair of numbers with a dash between.
+Any further options are given, on separate lines,
+to the daemon as options before the main scan command.
+For example:
+.code
+av_scanner = avast:/var/run/avast/scan.sock:FLAGS -fullfiles:SENSITIVITY -pup
+av_scanner = avast:192.168.2.22 5036
+.endd
+If you omit the argument, the default path
+&_/var/run/avast/scan.sock_&
+is used.
+If you use a remote host,
+you need to make Exim's spool directory available to it,
+as the scanner is passed a file path, not file contents.
+For information about available commands and their options you may use 
+.code
+$ socat UNIX:/var/run/avast/scan.sock STDIO:
+    FLAGS
+    SENSITIVITY
+    PACK
+.endd
+.wen
+
+

 .vitem &%aveserver%&
 .cindex "virus scanners" "Kaspersky"
 This is the scanner daemon of Kaspersky Version 5. You can get a trial version
 .vitem &%aveserver%&
 .cindex "virus scanners" "Kaspersky"
 This is the scanner daemon of Kaspersky Version 5. You can get a trial version


@@ -28554,6 +30477,7 @@ number, and a port, separated by space, as in the second of these examples:
 av_scanner = clamd:/opt/clamd/socket
 av_scanner = clamd:192.0.2.3 1234
 av_scanner = clamd:192.0.2.3 1234:local
 av_scanner = clamd:/opt/clamd/socket
 av_scanner = clamd:192.0.2.3 1234
 av_scanner = clamd:192.0.2.3 1234:local

+av_scanner = clamd:192.0.2.3 1234 : 192.0.2.4 1234

 .endd
 If the value of av_scanner points to a UNIX socket file or contains the local
 keyword, then the ClamAV interface will pass a filename containing the data
 .endd
 If the value of av_scanner points to a UNIX socket file or contains the local
 keyword, then the ClamAV interface will pass a filename containing the data


@@ -28562,6 +30486,22 @@ more efficient.  Normally in the TCP case, the data is streamed to ClamAV as
 Exim does not assume that there is a common filesystem with the remote host.
 There is an option WITH_OLD_CLAMAV_STREAM in &_src/EDITME_& available, should
 you be running a version of ClamAV prior to 0.95.
 Exim does not assume that there is a common filesystem with the remote host.
 There is an option WITH_OLD_CLAMAV_STREAM in &_src/EDITME_& available, should
 you be running a version of ClamAV prior to 0.95.

+
+The final example shows that multiple TCP targets can be specified.  Exim will
+randomly use one for each incoming email (i.e. it load balances them).  Note
+that only TCP targets may be used if specifying a list of scanners; a UNIX
+socket cannot be mixed in with TCP targets.  If one of the servers becomes
+unavailable, Exim will try the remaining one(s) until it finds one that works.
+When a clamd server becomes unreachable, Exim will log a message.  Exim does
+not keep track of scanner state between multiple messages, and the scanner
+selection is random, so the message will get logged in the mainlog for each
+email that the down scanner gets chosen first (message wrapped to be readable):
+.code
+2013-10-09 14:30:39 1VTumd-0000Y8-BQ malware acl condition:
+   clamd: connection to localhost, port 3310 failed
+   (Connection refused)
+.endd
+

 If the option is unset, the default is &_/tmp/clamd_&. Thanks to David Saez for
 contributing the code for this scanner.
 
 If the option is unset, the default is &_/tmp/clamd_&. Thanks to David Saez for
 contributing the code for this scanner.
 


@@ -28602,9 +30542,13 @@ av_scanner = cmdline:\
 .endd
 .vitem &%drweb%&
 .cindex "virus scanners" "DrWeb"
 .endd
 .vitem &%drweb%&
 .cindex "virus scanners" "DrWeb"

-The DrWeb daemon scanner (&url(http://www.sald.com/)) interface takes one
-argument, either a full path to a UNIX socket, or an IP address and port
-separated by white space, as in these examples:
+The DrWeb daemon scanner (&url(http://www.sald.com/)) interface
+takes one option,
+either a full path to a UNIX socket,
+or host and port specifiers separated by white space.
+The host may be a name or an IP address; the port is either a
+single number or a pair of numbers with a dash between.
+For example:

 .code
 av_scanner = drweb:/var/run/drwebd.sock
 av_scanner = drweb:192.168.2.20 31337
 .code
 av_scanner = drweb:/var/run/drwebd.sock
 av_scanner = drweb:192.168.2.20 31337


@@ -28612,6 +30556,17 @@ av_scanner = drweb:192.168.2.20 31337
 If you omit the argument, the default path &_/usr/local/drweb/run/drwebd.sock_&
 is used. Thanks to Alex Miller for contributing the code for this scanner.
 
 If you omit the argument, the default path &_/usr/local/drweb/run/drwebd.sock_&
 is used. Thanks to Alex Miller for contributing the code for this scanner.
 

+.vitem &%f-protd%&
+.cindex "virus scanners" "f-protd"
+The f-protd scanner is accessed via HTTP over TCP.
+One argument is taken, being a space-separated hostname and port number
+(or port-range).
+For example:
+.code
+av_scanner = f-protd:localhost 10200-10204
+.endd
+If you omit the argument, the default values show above are used.
+

 .vitem &%fsecure%&
 .cindex "virus scanners" "F-Secure"
 The F-Secure daemon scanner (&url(http://www.f-secure.com)) takes one
 .vitem &%fsecure%&
 .cindex "virus scanners" "F-Secure"
 The F-Secure daemon scanner (&url(http://www.f-secure.com)) takes one


@@ -28646,6 +30601,24 @@ av_scanner = mksd:2
 .endd
 You can safely omit this option (the default value is 1).
 
 .endd
 You can safely omit this option (the default value is 1).
 

+.vitem &%sock%&
+.cindex "virus scanners" "simple socket-connected"
+This is a general-purpose way of talking to simple scanner daemons
+running on the local machine.
+There are four options:
+an address (which may be an IP addres and port, or the path of a Unix socket),
+a commandline to send (may include a single %s which will be replaced with
+the path to the mail file to be scanned),
+an RE to trigger on from the returned data,
+an RE to extract malware_name from the returned data.
+For example:
+.code
+av_scanner = sock:127.0.0.1 6001:%s:(SPAM|VIRUS):(.*)\$
+.endd
+Default for the socket specifier is &_/tmp/malware.sock_&.
+Default for the commandline is &_%s\n_&.
+Both regular-expressions are required.
+

 .vitem &%sophie%&
 .cindex "virus scanners" "Sophos and Sophie"
 Sophie is a daemon that uses Sophos' &%libsavi%& library to scan for viruses.
 .vitem &%sophie%&
 .cindex "virus scanners" "Sophos and Sophie"
 Sophie is a daemon that uses Sophos' &%libsavi%& library to scan for viruses.


@@ -28672,7 +30645,10 @@ which case each use of the &%malware%& condition causes a new scan of the
 message.
 
 The &%malware%& condition takes a right-hand argument that is expanded before
 message.
 
 The &%malware%& condition takes a right-hand argument that is expanded before

-use. It can then be one of
+.new
+use and taken as a list, slash-separated by default.
+.wen
+The first element can then be one of

 
 .ilist
 &"true"&, &"*"&, or &"1"&, in which case the message is scanned for viruses.
 
 .ilist
 &"true"&, &"*"&, or &"1"&, in which case the message is scanned for viruses.


@@ -28685,11 +30661,25 @@ the condition fails immediately.
 A regular expression, in which case the message is scanned for viruses. The
 condition succeeds if a virus is found and its name matches the regular
 expression. This allows you to take special actions on certain types of virus.
 A regular expression, in which case the message is scanned for viruses. The
 condition succeeds if a virus is found and its name matches the regular
 expression. This allows you to take special actions on certain types of virus.

+.new
+Note that &"/"& characters in the RE must be doubled due to the list-processing,
+unless the separator is changed (in the usual way).
+.wen

 .endlist
 
 .endlist
 

-You can append &`/defer_ok`& to the &%malware%& condition to accept messages
-even if there is a problem with the virus scanner. Otherwise, such a problem
-causes the ACL to defer.
+You can append a &`defer_ok`& element to the &%malware%& argument list to accept
+messages even if there is a problem with the virus scanner.
+Otherwise, such a problem causes the ACL to defer.
+
+.new
+You can append a &`tmo=<val>`& element to the &%malware%& argument list to
+specify a non-default timeout.  The default is two minutes.
+For example:
+.code
+malware = * / defer_ok / tmo=10s
+.endd
+A timeout causes the ACL to defer.
+.wen

 
 .vindex "&$malware_name$&"
 When a virus is found, the condition sets up an expansion variable called
 
 .vindex "&$malware_name$&"
 When a virus is found, the condition sets up an expansion variable called


@@ -28733,14 +30723,23 @@ deny message = This message contains malware ($malware_name)
 .endd
 
 
 .endd
 
 

-.section "Scanning with SpamAssassin" "SECTscanspamass"
+.section "Scanning with SpamAssassin and Rspamd" "SECTscanspamass"

 .cindex "content scanning" "for spam"
 .cindex "spam scanning"
 .cindex "SpamAssassin"
 .cindex "content scanning" "for spam"
 .cindex "spam scanning"
 .cindex "SpamAssassin"

+.cindex "Rspamd"

 The &%spam%& ACL condition calls SpamAssassin's &%spamd%& daemon to get a spam
 The &%spam%& ACL condition calls SpamAssassin's &%spamd%& daemon to get a spam

-score and a report for the message. You can get SpamAssassin at
-&url(http://www.spamassassin.org), or, if you have a working Perl
-installation, you can use CPAN by running:
+score and a report for the message.
+.new
+Support is also provided for Rspamd (which can speak SpamAssassin's protocol but
+provides reduced functionality when used in this mode).
+
+For more information about installation and configuration of SpamAssassin or 
+Rspamd refer to their respective websites at
+&url(http://spamassassin.apache.org) and &url(http://www.rspamd.com)
+.wen
+
+SpamAssassin can be installed with CPAN by running:

 .code
 perl -MCPAN -e 'install Mail::SpamAssassin'
 .endd
 .code
 perl -MCPAN -e 'install Mail::SpamAssassin'
 .endd


@@ -28749,36 +30748,77 @@ documentation to see how you can tweak it. The default installation should work
 nicely, however.
 
 .oindex "&%spamd_address%&"
 nicely, however.
 
 .oindex "&%spamd_address%&"

-After having installed and configured SpamAssassin, start the &%spamd%& daemon.
-By default, it listens on 127.0.0.1, TCP port 783. If you use another host or
-port for &%spamd%&, you must set the &%spamd_address%& option in the global
-part of the Exim configuration as follows (example):
+By default, SpamAssassin listens on 127.0.0.1, TCP port 783 and if you 
+intend to use an instance running on the local host you do not need to set
+&%spamd_address%&. If you intend to use another host or port for SpamAssassin,
+you must set the &%spamd_address%& option in the global part of the Exim
+configuration as follows (example):

 .code
 spamd_address = 192.168.99.45 387
 .endd
 .code
 spamd_address = 192.168.99.45 387
 .endd

-You do not need to set this option if you use the default. As of version 2.60,
-&%spamd%& also supports communication over UNIX sockets. If you want to use
-these, supply &%spamd_address%& with an absolute file name instead of a
-address/port pair:
+
+.new
+To use Rspamd (which by default listens on all local addresses
+on TCP port 11333)
+you should add &%variant=rspamd%& after the address/port pair, for example:
+.code
+spamd_address = 127.0.0.1 11333 variant=rspamd
+.endd
+.wen
+
+As of version 2.60, &%SpamAssassin%& also supports communication over UNIX
+sockets. If you want to us these, supply &%spamd_address%& with an absolute
+file name instead of an address/port pair:

 .code
 spamd_address = /var/run/spamd_socket
 .endd
 You can have multiple &%spamd%& servers to improve scalability. These can
 reside on other hardware reachable over the network. To specify multiple
 &%spamd%& servers, put multiple address/port pairs in the &%spamd_address%&
 .code
 spamd_address = /var/run/spamd_socket
 .endd
 You can have multiple &%spamd%& servers to improve scalability. These can
 reside on other hardware reachable over the network. To specify multiple
 &%spamd%& servers, put multiple address/port pairs in the &%spamd_address%&

-option, separated with colons:
+option, separated with colons (the separator can be changed in the usual way):

 .code
 spamd_address = 192.168.2.10 783 : \
                 192.168.2.11 783 : \
                 192.168.2.12 783
 .endd
 .code
 spamd_address = 192.168.2.10 783 : \
                 192.168.2.11 783 : \
                 192.168.2.12 783
 .endd

-Up to 32 &%spamd%& servers are supported. The servers are queried in a random
-fashion. When a server fails to respond to the connection attempt, all other
+Up to 32 &%spamd%& servers are supported.
+When a server fails to respond to the connection attempt, all other

 servers are tried until one succeeds. If no server responds, the &%spam%&
 condition defers.
 
 servers are tried until one succeeds. If no server responds, the &%spam%&
 condition defers.
 

-&*Warning*&: It is not possible to use the UNIX socket connection method with
-multiple &%spamd%& servers.
+.new
+Unix and TCP socket specifications may be mixed in any order.
+Each element of the list is a list itself, space-separated by default
+and changeable in the usual way.
+
+For TCP socket specifications a host name or IP (v4 or v6, but
+subject to list-separator quoting rules) address can be used,
+and the port can be one or a dash-separated pair.
+In the latter case, the range is tried in strict order.
+
+Elements after the first for Unix sockets, or second for TCP socket,
+are options.
+The supported option are:
+.code
+variant=rspamd      Use Rspamd rather than SpamAssassin protocol
+time=<start>-<end>  Use only between these times of day
+tmo=<timespec>      Connection time limit.
+weight=<value>      Selection bias
+backup              Use only if all non-backup servers fail
+.endd
+
+Time specifications for the &`time`& option are <hour>.<minute>.<second>
+in the local time zone; each element being one or more digits.
+Either the seconds or both minutes and seconds, plus the leading &`.`&
+characters, may be omitted and will be taken as zero.
+
+Timeout specifications for the &`tmo`& option are the usual Exim
+time interval standard, eg. &`20s`& or &`1m`&.
+The default value is two minutes.
+
+Servers are queried in a random fashion, weighted by the selection bias.
+The default value for selection bias is 1.
+.wen

 
 The &%spamd_address%& variable is expanded before use if it starts with
 a dollar sign. In this case, the expansion may return a string that is
 
 The &%spamd_address%& variable is expanded before use if it starts with
 a dollar sign. In this case, the expansion may return a string that is


@@ -28795,7 +30835,10 @@ The right-hand side of the &%spam%& condition specifies a name. This is
 relevant if you have set up multiple SpamAssassin profiles. If you do not want
 to scan using a specific profile, but rather use the SpamAssassin system-wide
 default profile, you can scan for an unknown name, or simply use &"nobody"&.
 relevant if you have set up multiple SpamAssassin profiles. If you do not want
 to scan using a specific profile, but rather use the SpamAssassin system-wide
 default profile, you can scan for an unknown name, or simply use &"nobody"&.

-However, you must put something on the right-hand side.
+.new
+Rspamd does not use this setting. However, you must put something on the
+right-hand side.
+.wen

 
 The name allows you to use per-domain or per-user antispam profiles in
 principle, but this is not straightforward in practice, because a message may
 
 The name allows you to use per-domain or per-user antispam profiles in
 principle, but this is not straightforward in practice, because a message may


@@ -28849,6 +30892,14 @@ headers, since MUAs can match on such strings.
 .vitem &$spam_report$&
 A multiline text table, containing the full SpamAssassin report for the
 message. Useful for inclusion in headers or reject messages.
 .vitem &$spam_report$&
 A multiline text table, containing the full SpamAssassin report for the
 message. Useful for inclusion in headers or reject messages.

+
+.new
+.vitem &$spam_action$&
+For SpamAssassin either 'reject' or 'no action' depending on the
+spam score versus threshold.
+For Rspamd, the recommended action.
+.wen
+

 .endlist
 
 The &%spam%& condition caches its results unless expansion in
 .endlist
 
 The &%spam%& condition caches its results unless expansion in


@@ -30768,7 +32819,7 @@ they do not affect the values of the variables that refer to header lines.
 the transport cannot refer to the modified header lines, because such
 expansions all occur before the message is actually transported.
 
 the transport cannot refer to the modified header lines, because such
 expansions all occur before the message is actually transported.
 

-For both routers and transports, the result of expanding a &%headers_add%&
+For both routers and transports, the argument of a &%headers_add%&

 option must be in the form of one or more RFC 2822 header lines, separated by
 newlines (coded as &"\n"&). For example:
 .code
 option must be in the form of one or more RFC 2822 header lines, separated by
 newlines (coded as &"\n"&). For example:
 .code


@@ -30777,15 +32828,28 @@ headers_add = X-added-header: added by $primary_hostname\n\
 .endd
 Exim does not check the syntax of these added header lines.
 
 .endd
 Exim does not check the syntax of these added header lines.
 

-The result of expanding &%headers_remove%& must consist of a colon-separated
+Multiple &%headers_add%& options for a single router or transport can be
+specified; the values will append to a single list of header lines.
+Each header-line is separately expanded.
+
+The argument of a &%headers_remove%& option must consist of a colon-separated

 list of header names. This is confusing, because header names themselves are
 often terminated by colons. In this case, the colons are the list separators,
 not part of the names. For example:
 .code
 headers_remove = return-receipt-to:acknowledge-to
 .endd
 list of header names. This is confusing, because header names themselves are
 often terminated by colons. In this case, the colons are the list separators,
 not part of the names. For example:
 .code
 headers_remove = return-receipt-to:acknowledge-to
 .endd

-When &%headers_add%& or &%headers_remove%& is specified on a router, its value
-is expanded at routing time, and then associated with all addresses that are
+
+Multiple &%headers_remove%& options for a single router or transport can be
+specified; the arguments will append to a single header-names list.
+Each item is separately expanded.
+Note that colons in complex expansions which are used to
+form all or part of a &%headers_remove%& list
+will act as list separators.
+
+When &%headers_add%& or &%headers_remove%& is specified on a router,
+items are expanded at routing time,
+and then associated with all addresses that are

 accepted by that router, and also with any new addresses that it generates. If
 an address passes through several routers as a result of aliasing or
 forwarding, the changes are cumulative.
 accepted by that router, and also with any new addresses that it generates. If
 an address passes through several routers as a result of aliasing or
 forwarding, the changes are cumulative.


@@ -31022,6 +33086,8 @@ required for the transaction.
 If the remote server advertises support for the STARTTLS command, and Exim
 was built to support TLS encryption, it tries to start a TLS session unless the
 server matches &%hosts_avoid_tls%&. See chapter &<<CHAPTLS>>& for more details.
 If the remote server advertises support for the STARTTLS command, and Exim
 was built to support TLS encryption, it tries to start a TLS session unless the
 server matches &%hosts_avoid_tls%&. See chapter &<<CHAPTLS>>& for more details.

+Either a match in that or &%hosts_verify_avoid_tls%& apply when the transport
+is called for verification.

 
 If the remote server advertises support for the AUTH command, Exim scans
 the authenticators configuration for any suitable client settings, as described
 
 If the remote server advertises support for the AUTH command, Exim scans
 the authenticators configuration for any suitable client settings, as described


@@ -31617,13 +33683,10 @@ failing addresses with their error messages.
 The third item is used to introduce any text from pipe transports that is to be
 returned to the sender. It is omitted if there is no such text.
 .next
 The third item is used to introduce any text from pipe transports that is to be
 returned to the sender. It is omitted if there is no such text.
 .next

-The fourth item is used to introduce the copy of the message that is returned
-as part of the error report.
-.next
-The fifth item is added after the fourth one if the returned message is
-truncated because it is bigger than &%return_size_limit%&.
-.next
-The sixth item is added after the copy of the original message.
+.new
+The fourth, fifth and sixth items will be ignored and may be empty.
+The fields exist for back-compatibility
+.wen

 .endlist
 
 The default state (&%bounce_message_file%& unset) is equivalent to the
 .endlist
 
 The default state (&%bounce_message_file%& unset) is equivalent to the


@@ -32645,6 +34708,7 @@ timestamp. The flags are:
 &`<=`&     message arrival
 &`=>`&     normal message delivery
 &`->`&     additional address in same delivery
 &`<=`&     message arrival
 &`=>`&     normal message delivery
 &`->`&     additional address in same delivery

+&`>>`&     cutthrough message delivery

 &`*>`&     delivery suppressed by &%-N%&
 &`**`&     delivery failed; address bounced
 &`==`&     delivery deferred; temporary problem
 &`*>`&     delivery suppressed by &%-N%&
 &`**`&     delivery failed; address bounced
 &`==`&     delivery deferred; temporary problem


@@ -32744,6 +34808,11 @@ intermediate address(es) exist between the original and the final address, the
 last of these is given in parentheses after the final address. The R and T
 fields record the router and transport that were used to process the address.
 
 last of these is given in parentheses after the final address. The R and T
 fields record the router and transport that were used to process the address.
 

+If SMTP AUTH was used for the delivery there is an additional item A=
+followed by the name of the authenticator that was used.
+If an authenticated identification was set up by the authenticator's &%client_set_id%&
+option, this is logged too, separated by a colon from the authenticator name.
+

 If a shadow transport was run after a successful local delivery, the log line
 for the successful delivery has an item added on the end, of the form
 .display
 If a shadow transport was run after a successful local delivery, the log line
 for the successful delivery has an item added on the end, of the form
 .display


@@ -32759,6 +34828,12 @@ flagged with &`->`& instead of &`=>`&. When two or more messages are delivered
 down a single SMTP connection, an asterisk follows the IP address in the log
 lines for the second and subsequent messages.
 
 down a single SMTP connection, an asterisk follows the IP address in the log
 lines for the second and subsequent messages.
 

+.cindex "delivery" "cutthrough; logging"
+.cindex "cutthrough" "logging"
+When delivery is done in cutthrough mode it is flagged with &`>>`& and the log
+line precedes the reception line, since cutthrough waits for a possible
+rejection from the destination in case it can reject the sourced item.
+

 The generation of a reply message by a filter file gets logged as a
 &"delivery"& to the addressee, preceded by &">"&.
 
 The generation of a reply message by a filter file gets logged as a
 &"delivery"& to the addressee, preceded by &">"&.
 


@@ -32851,7 +34926,7 @@ at the end of its processing.
 A summary of the field identifiers that are used in log lines is shown in
 the following table:
 .display
 A summary of the field identifiers that are used in log lines is shown in
 the following table:
 .display

-&`A   `&        authenticator name (and optional id)
+&`A   `&        authenticator name (and optional id and sender)

 &`C   `&        SMTP confirmation on delivery
 &`    `&        command list for &"no mail in SMTP session"&
 &`CV  `&        certificate verification status
 &`C   `&        SMTP confirmation on delivery
 &`    `&        command list for &"no mail in SMTP session"&
 &`CV  `&        certificate verification status


@@ -32869,6 +34944,7 @@ the following table:
 &`R   `&        on &`<=`& lines: reference for local bounce
 &`    `&        on &`=>`&  &`**`& and &`==`& lines: router name
 &`S   `&        size of message
 &`R   `&        on &`<=`& lines: reference for local bounce
 &`    `&        on &`=>`&  &`**`& and &`==`& lines: router name
 &`S   `&        size of message

+&`SNI `&        server name indication from TLS client hello

 &`ST  `&        shadow transport name
 &`T   `&        on &`<=`& lines: message subject (topic)
 &`    `&        on &`=>`& &`**`& and &`==`& lines: transport name
 &`ST  `&        shadow transport name
 &`T   `&        on &`<=`& lines: message subject (topic)
 &`    `&        on &`=>`& &`**`& and &`==`& lines: transport name


@@ -32935,6 +35011,7 @@ log_selector = +arguments -retry_defer
 The list of optional log items is in the following table, with the default
 selection marked by asterisks:
 .display
 The list of optional log items is in the following table, with the default
 selection marked by asterisks:
 .display

+&` 8bitmime                   `&  received 8BITMIME status

 &`*acl_warn_skipped           `&  skipped &%warn%& statement in ACL
 &` address_rewrite            `&  address rewriting
 &` all_parents                `&  all parents in => lines
 &`*acl_warn_skipped           `&  skipped &%warn%& statement in ACL
 &` address_rewrite            `&  address rewriting
 &` all_parents                `&  all parents in => lines


@@ -32947,8 +35024,8 @@ selection marked by asterisks:
 &`*etrn                       `&  ETRN commands
 &`*host_lookup_failed         `&  as it says
 &` ident_timeout              `&  timeout for ident connection
 &`*etrn                       `&  ETRN commands
 &`*host_lookup_failed         `&  as it says
 &` ident_timeout              `&  timeout for ident connection

-&` incoming_interface         `&  incoming interface on <= lines
-&` incoming_port              `&  incoming port on <= lines
+&` incoming_interface         `&  local interface on <= and => lines
+&` incoming_port              `&  remote port on <= lines

 &`*lost_incoming_connection   `&  as it says (includes timeouts)
 &` outgoing_port              `&  add remote port to => lines
 &`*queue_run                  `&  start and end queue runs
 &`*lost_incoming_connection   `&  as it says (includes timeouts)
 &` outgoing_port              `&  add remote port to => lines
 &`*queue_run                  `&  start and end queue runs


@@ -32964,16 +35041,20 @@ selection marked by asterisks:
 &`*sender_verify_fail         `&  sender verification failures
 &`*size_reject                `&  rejection because too big
 &`*skip_delivery              `&  delivery skipped in a queue run
 &`*sender_verify_fail         `&  sender verification failures
 &`*size_reject                `&  rejection because too big
 &`*skip_delivery              `&  delivery skipped in a queue run

-&` smtp_confirmation          `&  SMTP confirmation on => lines
+&`*smtp_confirmation          `&  SMTP confirmation on => lines

 &` smtp_connection            `&  SMTP connections
 &` smtp_incomplete_transaction`&  incomplete SMTP transactions
 &` smtp_connection            `&  SMTP connections
 &` smtp_incomplete_transaction`&  incomplete SMTP transactions

+&` smtp_mailauth              `&  AUTH argument to MAIL commands

 &` smtp_no_mail               `&  session with no MAIL commands
 &` smtp_protocol_error        `&  SMTP protocol errors
 &` smtp_syntax_error          `&  SMTP syntax errors
 &` subject                    `&  contents of &'Subject:'& on <= lines
 &` smtp_no_mail               `&  session with no MAIL commands
 &` smtp_protocol_error        `&  SMTP protocol errors
 &` smtp_syntax_error          `&  SMTP syntax errors
 &` subject                    `&  contents of &'Subject:'& on <= lines

-&` tls_certificate_verified   `&  certificate verification status
+.new
+&`*tls_certificate_verified   `&  certificate verification status
+.wen

 &`*tls_cipher                 `&  TLS cipher suite on <= and => lines
 &` tls_peerdn                 `&  TLS peer DN on <= and => lines
 &`*tls_cipher                 `&  TLS cipher suite on <= and => lines
 &` tls_peerdn                 `&  TLS peer DN on <= and => lines

+&` tls_sni                    `&  TLS SNI on <= lines

 &` unknown_in_list            `&  DNS lookup failed in list match
 
 &` all                        `&  all of the above
 &` unknown_in_list            `&  DNS lookup failed in list match
 
 &` all                        `&  all of the above


@@ -32981,6 +35062,14 @@ selection marked by asterisks:
 More details on each of these items follows:
 
 .ilist
 More details on each of these items follows:
 
 .ilist

+.cindex "8BITMIME"
+.cindex "log" "8BITMIME"
+&%8bitmime%&: This causes Exim to log any 8BITMIME status of received messages,
+which may help in tracking down interoperability issues with ancient MTAs
+that are not 8bit clean.  This is added to the &"<="& line, tagged with
+&`M8S=`& and a value of &`0`&, &`7`& or &`8`&, corresponding to "not given",
+&`7BIT`& and &`8BITMIME`& respectively.
+.next

 .cindex "&%warn%& ACL verb" "log when skipping"
 &%acl_warn_skipped%&: When an ACL &%warn%& statement is skipped because one of
 its conditions cannot be evaluated, a log line to this effect is written if
 .cindex "&%warn%& ACL verb" "log when skipping"
 &%acl_warn_skipped%&: When an ACL &%warn%& statement is skipped because one of
 its conditions cannot be evaluated, a log line to this effect is written if


@@ -33055,12 +35144,16 @@ routing email addresses, but it does apply to &"byname"& lookups.
 client's ident port times out.
 .next
 .cindex "log" "incoming interface"
 client's ident port times out.
 .next
 .cindex "log" "incoming interface"

+.cindex "log" "local interface"
+.cindex "log" "local address and port"
+.cindex "TCP/IP" "logging local address and port"

 .cindex "interface" "logging"
 &%incoming_interface%&: The interface on which a message was received is added
 to the &"<="& line as an IP address in square brackets, tagged by I= and
 followed by a colon and the port number. The local interface and port are also
 .cindex "interface" "logging"
 &%incoming_interface%&: The interface on which a message was received is added
 to the &"<="& line as an IP address in square brackets, tagged by I= and
 followed by a colon and the port number. The local interface and port are also

-added to other SMTP log lines, for example &"SMTP connection from"&, and to
-rejection lines.
+added to other SMTP log lines, for example &"SMTP connection from"& and to
+rejection lines
+and (despite the name) the local interface is added to &"=>"& lines..

 .next
 .cindex "log" "incoming remote port"
 .cindex "port" "logging remote"
 .next
 .cindex "log" "incoming remote port"
 .cindex "port" "logging remote"


@@ -33167,7 +35260,8 @@ The message that is written is &"spool file is locked"&.
 .next
 .cindex "log" "smtp confirmation"
 .cindex "SMTP" "logging confirmation"
 .next
 .cindex "log" "smtp confirmation"
 .cindex "SMTP" "logging confirmation"

-&%smtp_confirmation%&: The response to the final &"."& in the SMTP dialogue for
+.cindex "LMTP" "logging confirmation"
+&%smtp_confirmation%&: The response to the final &"."& in the SMTP or LMTP dialogue for

 outgoing messages is added to delivery log lines in the form &`C=`&<&'text'&>.
 A number of MTAs (including Exim) return an identifying string in this
 response.
 outgoing messages is added to delivery log lines in the form &`C=`&<&'text'&>.
 A number of MTAs (including Exim) return an identifying string in this
 response.


@@ -33226,6 +35320,11 @@ the last 20 are listed, preceded by &"..."&. However, with the default
 setting of 10 for &%smtp_accep_max_nonmail%&, the connection will in any case
 have been aborted before 20 non-mail commands are processed.
 .next
 setting of 10 for &%smtp_accep_max_nonmail%&, the connection will in any case
 have been aborted before 20 non-mail commands are processed.
 .next

+&%smtp_mailauth%&: A third subfield with the authenticated sender,
+colon-separated, is appended to the A= item for a message arrival or delivery
+log line, if an AUTH argument to the SMTP MAIL command (see &<<SECTauthparamail>>&)
+was accepted or used.
+.next

 .cindex "log" "SMTP protocol error"
 .cindex "SMTP" "logging protocol error"
 &%smtp_protocol_error%&: A log line is written for every SMTP protocol error
 .cindex "log" "SMTP protocol error"
 .cindex "SMTP" "logging protocol error"
 &%smtp_protocol_error%&: A log line is written for every SMTP protocol error


@@ -33269,6 +35368,12 @@ connection, the cipher suite used is added to the log line, preceded by X=.
 connection, and a certificate is supplied by the remote host, the peer DN is
 added to the log line, preceded by DN=.
 .next
 connection, and a certificate is supplied by the remote host, the peer DN is
 added to the log line, preceded by DN=.
 .next

+.cindex "log" "TLS SNI"
+.cindex "TLS" "logging SNI"
+&%tls_sni%&: When a message is received over an encrypted connection, and
+the remote host provided the Server Name Indication extension, the SNI is
+added to the log line, preceded by SNI=.
+.next

 .cindex "log" "DNS failure in list"
 &%unknown_in_list%&: This setting causes a log entry to be written when the
 result of a list match is failure because a DNS lookup failed.
 .cindex "log" "DNS failure in list"
 &%unknown_in_list%&: This setting causes a log entry to be written when the
 result of a list match is failure because a DNS lookup failed.


@@ -33385,20 +35490,26 @@ This utility is a Perl script contributed by Matt Hubbard. It runs
 .code
 exim -bpu
 .endd
 .code
 exim -bpu
 .endd

-to obtain a queue listing with undelivered recipients only, and then greps the
-output to select messages that match given criteria. The following selection
-options are available:
+or (in case &*-a*& switch is specified)
+.code
+exim -bp
+.endd
+The &*-C*& option is used to specify an alternate &_exim.conf_& which might
+contain alternate exim configuration the queue management might be using.
+
+to obtain a queue listing, and then greps the output to select messages 
+that match given criteria. The following selection options are available:

 
 .vlist
 .vitem &*-f*&&~<&'regex'&>
 
 .vlist
 .vitem &*-f*&&~<&'regex'&>

-Match the sender address. The field that is tested is enclosed in angle
-brackets, so you can test for bounce messages with
+Match the sender address using a case-insensitive search. The field that is
+tested is enclosed in angle brackets, so you can test for bounce messages with

 .code
 exiqgrep -f '^<>$'
 .endd
 .vitem &*-r*&&~<&'regex'&>
 .code
 exiqgrep -f '^<>$'
 .endd
 .vitem &*-r*&&~<&'regex'&>

-Match a recipient address. The field that is tested is not enclosed in angle
-brackets.
+Match a recipient address using a case-insensitve search. The field that is
+tested is not enclosed in angle brackets.

 
 .vitem &*-s*&&~<&'regex'&>
 Match against the size field.
 
 .vitem &*-s*&&~<&'regex'&>
 Match against the size field.


@@ -33434,6 +35545,9 @@ Brief format &-- one line per message.
 
 .vitem &*-R*&
 Display messages in reverse order.
 
 .vitem &*-R*&
 Display messages in reverse order.

+
+.vitem &*-a*&
+Include delivered recipients in queue listing.

 .endlist
 
 There is one more option, &%-h%&, which outputs a list of options.
 .endlist
 
 There is one more option, &%-h%&, which outputs a list of options.


@@ -33489,7 +35603,7 @@ The input files can be in Exim log format or syslog format.
 If a matching log line is not associated with a specific message, it is
 included in &'exigrep'&'s output without any additional lines. The usage is:
 .display
 If a matching log line is not associated with a specific message, it is
 included in &'exigrep'&'s output without any additional lines. The usage is:
 .display

-&`exigrep [-t<`&&'n'&&`>] [-I] [-l] [-v] <`&&'pattern'&&`> [<`&&'log file'&&`>] ...`&
+&`exigrep [-t<`&&'n'&&`>] [-I] [-l] [-M] [-v] <`&&'pattern'&&`> [<`&&'log file'&&`>] ...`&

 .endd
 If no log file names are given on the command line, the standard input is read.
 
 .endd
 If no log file names are given on the command line, the standard input is read.
 


@@ -33510,6 +35624,19 @@ regular expression.
 The &%-v%& option inverts the matching condition. That is, a line is selected
 if it does &'not'& match the pattern.
 
 The &%-v%& option inverts the matching condition. That is, a line is selected
 if it does &'not'& match the pattern.
 

+The &%-M%& options means &"related messages"&. &'exigrep'& will show messages
+that are generated as a result/response to a message that &'exigrep'& matched
+normally.
+
+Example of &%-M%&:
+user_a sends a message to user_b, which generates a bounce back to user_b. If
+&'exigrep'& is used to search for &"user_a"&, only the first message will be
+displayed.  But if &'exigrep'& is used to search for &"user_b"&, the first and
+the second (bounce) message will be displayed. Using &%-M%& with &'exigrep'&
+when searching for &"user_a"& will show both messages since the bounce is
+&"related"& to or a &"result"& of the first message that was found by the
+search term.
+

 If the location of a &'zcat'& command is known from the definition of
 ZCAT_COMMAND in &_Local/Makefile_&, &'exigrep'& automatically passes any file
 whose name ends in COMPRESS_SUFFIX through &'zcat'& as it searches it.
 If the location of a &'zcat'& command is known from the definition of
 ZCAT_COMMAND in &_Local/Makefile_&, &'exigrep'& automatically passes any file
 whose name ends in COMPRESS_SUFFIX through &'zcat'& as it searches it.


@@ -34059,6 +36186,12 @@ End
 In order to see the contents of messages on the queue, and to operate on them,
 &'eximon'& must either be run as root or by an admin user.
 
 In order to see the contents of messages on the queue, and to operate on them,
 &'eximon'& must either be run as root or by an admin user.
 

+The command-line parameters of &'eximon'& are passed to &_eximon.bin_& and may
+contain X11 resource parameters interpreted by the X11 library.  In addition,
+if the first parameter starts with the string "gdb" then it is removed and the
+binary is invoked under gdb (the parameter is used as the gdb command-name, so
+versioned variants of gdb can be invoked).
+

 The monitor's window is divided into three parts. The first contains one or
 more stripcharts and two action buttons, the second contains a &"tail"& of the
 main log file, and the third is a display of the queue of messages awaiting
 The monitor's window is divided into three parts. The first contains one or
 more stripcharts and two action buttons, the second contains a &"tail"& of the
 main log file, and the third is a display of the queue of messages awaiting


@@ -34616,6 +36749,85 @@ are given in chapter &<<CHAPappendfile>>&.
 
 
 
 
 
 

+.section "Running local commands" "SECTsecconslocalcmds"
+.cindex "security" "local commands"
+.cindex "security" "command injection attacks"
+There are a number of ways in which an administrator can configure Exim to run
+commands based upon received, untrustworthy, data. Further, in some
+configurations a user who can control a &_.forward_& file can also arrange to
+run commands. Configuration to check includes, but is not limited to:
+
+.ilist
+Use of &%use_shell%& in the pipe transport: various forms of shell command
+injection may be possible with this option present. It is dangerous and should
+be used only with considerable caution. Consider constraints which whitelist
+allowed characters in a variable which is to be used in a pipe transport that
+has &%use_shell%& enabled.
+.next
+A number of options such as &%forbid_filter_run%&, &%forbid_filter_perl%&,
+&%forbid_filter_dlfunc%& and so forth which restrict facilities available to
+&_.forward_& files in a redirect router. If Exim is running on a central mail
+hub to which ordinary users do not have shell access, but home directories are
+NFS mounted (for instance) then administrators should review the list of these
+forbid options available, and should bear in mind that the options that may
+need forbidding can change as new features are added between releases.
+.next
+The &%${run...}%& expansion item does not use a shell by default, but
+administrators can configure use of &_/bin/sh_& as part of the command.
+Such invocations should be viewed with prejudicial suspicion.
+.next
+Administrators who use embedded Perl are advised to explore how Perl's
+taint checking might apply to their usage.
+.next
+Use of &%${expand...}%& is somewhat analagous to shell's eval builtin and
+administrators are well advised to view its use with suspicion, in case (for
+instance) it allows a local-part to contain embedded Exim directives.
+.next
+Use of &%${match_local_part...}%& and friends becomes more dangerous if
+Exim was built with EXPAND_LISTMATCH_RHS defined: the second string in
+each can reference arbitrary lists and files, rather than just being a list
+of opaque strings.
+The EXPAND_LISTMATCH_RHS option was added and set false by default because of
+real-world security vulnerabilities caused by its use with untrustworthy data
+injected in, for SQL injection attacks.
+Consider the use of the &%inlisti%& expansion condition instead.
+.endlist
+
+
+
+
+.section "Trust in configuration data" "SECTsecconfdata"
+.cindex "security" "data sources"
+.cindex "security" "regular expressions"
+.cindex "regular expressions" "security"
+.cindex "PCRE" "security"
+If configuration data for Exim can come from untrustworthy sources, there
+are some issues to be aware of:
+
+.ilist
+Use of &%${expand...}%& may provide a path for shell injection attacks.
+.next
+Letting untrusted data provide a regular expression is unwise.
+.next
+Using &%${match...}%& to apply a fixed regular expression against untrusted
+data may result in pathological behaviour within PCRE.  Be aware of what
+"backtracking" means and consider options for being more strict with a regular
+expression. Avenues to explore include limiting what can match (avoiding &`.`&
+when &`[a-z0-9]`& or other character class will do), use of atomic grouping and
+possessive quantifiers or just not using regular expressions against untrusted
+data.
+.next
+It can be important to correctly use &%${quote:...}%&,
+&%${quote_local_part:...}%& and &%${quote_%&<&'lookup-type'&>&%:...}%& expansion
+items to ensure that data is correctly constructed.
+.next
+Some lookups might return multiple results, even though normal usage is only
+expected to yield one result.
+.endlist
+
+
+
+

 .section "IPv4 source routing" "SECID272"
 .cindex "source routing" "in IP packets"
 .cindex "IP source routing"
 .section "IPv4 source routing" "SECID272"
 .cindex "source routing" "in IP packets"
 .cindex "IP source routing"


@@ -35073,17 +37285,24 @@ unqualified domain &'foundation'&.
 . ////////////////////////////////////////////////////////////////////////////
 . ////////////////////////////////////////////////////////////////////////////
 
 . ////////////////////////////////////////////////////////////////////////////
 . ////////////////////////////////////////////////////////////////////////////
 

-.chapter "Support for DKIM (DomainKeys Identified Mail) - RFC4871" "CHID12" &&&
+.chapter "Support for DKIM (DomainKeys Identified Mail)" "CHAPdkim" &&&

          "DKIM Support"
 .cindex "DKIM"
 
          "DKIM Support"
 .cindex "DKIM"
 

+DKIM is a mechanism by which messages sent by some entity can be provably
+linked to a domain which that entity controls.  It permits reputation to
+be tracked on a per-domain basis, rather than merely upon source IP address.
+DKIM is documented in RFC 4871.
+

 Since version 4.70, DKIM support is compiled into Exim by default. It can be
 disabled by setting DISABLE_DKIM=yes in Local/Makefile.
 
 Exim's DKIM implementation allows to
 .olist
 Sign outgoing messages: This function is implemented in the SMTP transport.
 Since version 4.70, DKIM support is compiled into Exim by default. It can be
 disabled by setting DISABLE_DKIM=yes in Local/Makefile.
 
 Exim's DKIM implementation allows to
 .olist
 Sign outgoing messages: This function is implemented in the SMTP transport.

-It can co-exist with all other Exim features, including transport filters.
+It can co-exist with all other Exim features
+(including transport filters)
+except cutthrough delivery.

 .next
 Verify signatures in incoming messages: This is implemented by an additional
 ACL (acl_smtp_dkim), which can be called several times per message, with
 .next
 Verify signatures in incoming messages: This is implemented by an additional
 ACL (acl_smtp_dkim), which can be called several times per message, with


@@ -35097,9 +37316,12 @@ Exim's standard controls.
 Please note that verification of DKIM signatures in incoming mail is turned
 on by default for logging purposes. For each signature in incoming email,
 exim will log a line displaying the most important signature details, and the
 Please note that verification of DKIM signatures in incoming mail is turned
 on by default for logging purposes. For each signature in incoming email,
 exim will log a line displaying the most important signature details, and the

-signature status. Here is an example:
+signature status. Here is an example (with line-breaks added for clarity):

 .code
 .code

-2009-09-09 10:22:28 1MlIRf-0003LU-U3 DKIM: d=facebookmail.com s=q1-2009b c=relaxed/relaxed a=rsa-sha1 i=@facebookmail.com t=1252484542 [verification succeeded]
+2009-09-09 10:22:28 1MlIRf-0003LU-U3 DKIM:
+    d=facebookmail.com s=q1-2009b
+    c=relaxed/relaxed a=rsa-sha1
+    i=@facebookmail.com t=1252484542 [verification succeeded]

 .endd
 You might want to turn off DKIM verification processing entirely for internal
 or relay mail sources. To do that, set the &%dkim_disable_verify%& ACL
 .endd
 You might want to turn off DKIM verification processing entirely for internal
 or relay mail sources. To do that, set the &%dkim_disable_verify%& ACL


@@ -35171,6 +37393,10 @@ used.
 Verification of DKIM signatures in incoming email is implemented via the
 &%acl_smtp_dkim%& ACL. By default, this ACL is called once for each
 syntactically(!) correct signature in the incoming message.
 Verification of DKIM signatures in incoming email is implemented via the
 &%acl_smtp_dkim%& ACL. By default, this ACL is called once for each
 syntactically(!) correct signature in the incoming message.

+A missing ACL definition defaults to accept.
+If any ACL call does not acccept, the message is not accepted.
+If a cutthrough delivery was in progress for the message it is
+summarily dropped (having wasted the transmission effort).

 
 To evaluate the signature in the ACL a large number of expansion variables
 containing the signature status and its details are set up during the
 
 To evaluate the signature in the ACL a large number of expansion variables
 containing the signature status and its details are set up during the


@@ -35285,7 +37511,7 @@ integer size comparisons against this value.
 A colon-separated list of names of headers included in the signature.
 .vitem &%$dkim_key_testing%&
 "1" if the key record has the "testing" flag set, "0" if not.
 A colon-separated list of names of headers included in the signature.
 .vitem &%$dkim_key_testing%&
 "1" if the key record has the "testing" flag set, "0" if not.

-.vitem &%$nosubdomains%&
+.vitem &%$dkim_key_nosubdomains%&

 "1" if the key record forbids subdomaining, "0" otherwise.
 .vitem &%$dkim_key_srvtype%&
 Service type (tag s=) from the key record. Defaults to "*" if not specified
 "1" if the key record forbids subdomaining, "0" otherwise.
 .vitem &%$dkim_key_srvtype%&
 Service type (tag s=) from the key record. Defaults to "*" if not specified


@@ -35307,7 +37533,7 @@ for a match against the domain or identity that the ACL is currently verifying
 verb to a group of domains or identities. For example:
 
 .code
 verb to a group of domains or identities. For example:
 
 .code

-# Warn when message apparently from GMail has no signature at all
+# Warn when Mail purportedly from GMail has no signature at all

 warn log_message = GMail sender without DKIM signature
      sender_domains = gmail.com
      dkim_signers = gmail.com
 warn log_message = GMail sender without DKIM signature
      sender_domains = gmail.com
      dkim_signers = gmail.com


@@ -35316,11 +37542,11 @@ warn log_message = GMail sender without DKIM signature
 
 .vitem &%dkim_status%&
 ACL condition that checks a colon-separated list of possible DKIM verification
 
 .vitem &%dkim_status%&
 ACL condition that checks a colon-separated list of possible DKIM verification

-results agains the actual result of verification. This is typically used
-to restrict an ACL verb to a list of verification outcomes, like:
+results against the actual result of verification. This is typically used
+to restrict an ACL verb to a list of verification outcomes, for example:

 
 .code
 
 .code

-deny message = Message from Paypal with invalid or missing signature
+deny message = Mail from Paypal with invalid/missing signature

      sender_domains = paypal.com:paypal.de
      dkim_signers = paypal.com:paypal.de
      dkim_status = none:invalid:fail
      sender_domains = paypal.com:paypal.de
      dkim_signers = paypal.com:paypal.de
      dkim_status = none:invalid:fail


@@ -35362,6 +37588,12 @@ Add to &_src/config.h.defaults_& the line:
 Edit &_src/drtables.c_&, adding conditional code to pull in the private header
 and create a table entry as is done for all the other drivers and lookup types.
 .next
 Edit &_src/drtables.c_&, adding conditional code to pull in the private header
 and create a table entry as is done for all the other drivers and lookup types.
 .next

+Edit &_scripts/lookups-Makefile_& if this is a new lookup; there is a for-loop
+near the bottom, ranging the &`name_mod`& variable over a list of all lookups.
+Add your &`NEWDRIVER`& to that list.
+As long as the dynamic module would be named &_newdriver.so_&, you can use the
+simple form that most lookups have.
+.next

 Edit &_Makefile_& in the appropriate sub-directory (&_src/routers_&,
 &_src/transports_&, &_src/auths_&, or &_src/lookups_&); add a line for the new
 driver or lookup type and add it to the definition of OBJ.
 Edit &_Makefile_& in the appropriate sub-directory (&_src/routers_&,
 &_src/transports_&, &_src/auths_&, or &_src/lookups_&); add a line for the new
 driver or lookup type and add it to the definition of OBJ.