Enforce that only smtp transports can be used for verify callouts. Bug 1445

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

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 19fb321ea0118318f409bf4f75db895f36e9276e..c412c1e1675e124f5c7909a77fe6eabf6a08837f 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 "4.80"
 . /////////////////////////////////////////////////////////////////////////////
 
 .set previousversion "4.80"

-.set version "4.80"
+.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>17 May 2012</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>4.80</revnumber>
-  <date>17 May 2012</date>
+.versiondatexml

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

-<copyright><year>2012</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"


@@ -2298,7 +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).


@@ -2678,14 +2710,12 @@ 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.
 

-.new

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

-.wen

 
 .vitem &%-B%&<&'type'&>
 .oindex "&%-B%&"
 
 .vitem &%-B%&<&'type'&>
 .oindex "&%-B%&"


@@ -2946,7 +2976,6 @@ 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.
 

-.new

 . // Keep :help first, then the rest in alphabetical order
 .vitem &%-bI:help%&
 .oindex "&%-bI:help%&"
 . // Keep :help first, then the rest in alphabetical order
 .vitem &%-bI:help%&
 .oindex "&%-bI:help%&"


@@ -2972,7 +3001,6 @@ 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.
 &`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.

-.wen

 
 .vitem &%-bm%&
 .oindex "&%-bm%&"
 
 .vitem &%-bm%&
 .oindex "&%-bm%&"


@@ -3087,11 +3115,9 @@ 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.
 

-.new

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

-.wen

 
 .cindex "daemon" "process id (pid)"
 .cindex "pid (process id)" "of daemon"
 
 .cindex "daemon" "process id (pid)"
 .cindex "pid (process id)" "of daemon"


@@ -3696,7 +3722,6 @@ if &%-f%& is also present, it overrides &"From&~"&.
 .vitem &%-G%&
 .oindex "&%-G%&"
 .cindex "submission fixups, suppressing (command-line)"
 .vitem &%-G%&
 .oindex "&%-G%&"
 .cindex "submission fixups, suppressing (command-line)"

-.new

 This option is equivalent to an ACL applying:
 .code
 control = suppress_local_fixups
 This option is equivalent to an ACL applying:
 .code
 control = suppress_local_fixups


@@ -3707,7 +3732,6 @@ in future.
 
 As this affects audit information, the caller must be a trusted user to use
 this option.
 
 As this affects audit information, the caller must be a trusted user to use
 this option.

-.wen

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


@@ -3725,7 +3749,6 @@ 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%&.
 

-.new

 .vitem &%-L%&&~<&'tag'&>
 .oindex "&%-L%&"
 .cindex "syslog" "process name; set with flag"
 .vitem &%-L%&&~<&'tag'&>
 .oindex "&%-L%&"
 .cindex "syslog" "process name; set with flag"


@@ -3736,7 +3759,6 @@ 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.
 effect, so early configuration file errors will not honour this flag.
 
 The tag should not be longer than 32 characters.

-.wen

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


@@ -4308,7 +4330,7 @@ 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%&


@@ -4600,12 +4622,10 @@ 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.
 
 It sets &%-x%& when calling the MTA from its &%mail%& command. Exim ignores
 this option.
 

-.new

 .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 &%-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.

-.wen

 .endlist
 
 .ecindex IIDclo1
 .endlist
 
 .ecindex IIDclo1


@@ -6911,6 +6931,14 @@ 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.


@@ -7012,6 +7040,18 @@ 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.
 

+.new
+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_&.
+.wen
+

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


@@ -8144,7 +8184,7 @@ 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


@@ -8224,10 +8264,13 @@ 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


@@ -8255,6 +8298,37 @@ 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.
 

+To explain the host/ip processing logic a different way for the same ACL:
+
+.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"


@@ -8313,7 +8387,7 @@ 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


@@ -8513,7 +8587,7 @@ 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.


@@ -8767,12 +8841,12 @@ 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
 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 overwritten.  If the ACL sets
+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.
 a value using a "message =" modifier and returns accept or deny, the value becomes
 the result of the expansion.

-If no message was set and the ACL returned accept or deny
-the value is an empty string.
-If the ACL returned defer the result is a forced-fail.  Otherwise the expansion fails.
+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 "&*${dlfunc{*&<&'file'&>&*}{*&<&'function'&>&*}{*&<&'arg'&>&*}&&&
 
 
 .vitem "&*${dlfunc{*&<&'file'&>&*}{*&<&'function'&>&*}{*&<&'arg'&>&*}&&&


@@ -9107,6 +9181,44 @@ 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


@@ -9579,6 +9691,29 @@ 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"


@@ -9733,6 +9868,16 @@ 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"


@@ -9766,12 +9911,12 @@ when &%length%& is used as an operator.
 The string is interpreted as a list and the number of items is returned.
 
 
 The string is interpreted as a list and the number of items is returned.
 
 

-.vitem &*${listnamed:*&<&'name'&>&*}*&&~and&~&*${list_*&<&'type'&>&*name*&>&*}*&
+.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.
 .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 if given it must be one of "a", "d", "h" or "l"
+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.
 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.


@@ -9899,12 +10044,12 @@ dotted-nibble hexadecimal form.  In both cases, this is the "natural" form
 for DNS.  For example,
 .code
 ${reverse_ip:192.0.2.4}
 for DNS.  For example,
 .code
 ${reverse_ip:192.0.2.4}

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

 .endd
 returns
 .code
 4.2.0.192
 .endd
 returns
 .code
 4.2.0.192

-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
+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
 
 


@@ -10026,6 +10171,14 @@ 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
 
 


@@ -10083,7 +10236,7 @@ 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
 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 overwritten.  If the ACL sets
+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.
 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.


@@ -10283,6 +10436,8 @@ ${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'&>&*}*&


@@ -10826,7 +10981,16 @@ 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 &$authenticated_sender$&


@@ -11039,6 +11203,12 @@ 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


@@ -11709,6 +11879,12 @@ 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 "&$runrc$&"


@@ -11800,7 +11976,6 @@ 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
 &$authenticated_id$&.
 

-.new

 .vitem &$sender_host_dnssec$&
 .vindex "&$sender_host_dnssec$&"
 If &$sender_host_name$& has been populated (by reference, &%hosts_lookup%& or
 .vitem &$sender_host_dnssec$&
 .vindex "&$sender_host_dnssec$&"
 If &$sender_host_name$& has been populated (by reference, &%hosts_lookup%& or


@@ -11811,7 +11986,7 @@ 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
 It is likely that you will need to coerce DNSSEC support on in the resolver
 library, by setting:
 .code

-dns_use_dnssec = 1
+dns_dnssec_ok = 1

 .endd
 
 Exim does not perform DNSSEC validation itself, instead leaving that to a
 .endd
 
 Exim does not perform DNSSEC validation itself, instead leaving that to a


@@ -11822,7 +11997,6 @@ 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.
 
 If you have changed &%host_lookup_order%& so that &`bydns`& is not the first
 mechanism in the list, then this variable will be false.

-.wen

 
 
 .vitem &$sender_host_name$&
 
 
 .vitem &$sender_host_name$&


@@ -12163,6 +12337,12 @@ 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,
 .vitem &$value$&
 .vindex "&$value$&"
 This variable contains the result of an expansion lookup, extraction operation,


@@ -12871,9 +13051,7 @@ listed in more than one group.
 .section "TLS" "SECID108"
 .table2
 .row &%gnutls_compat_mode%&          "use GnuTLS compatibility mode"
 .section "TLS" "SECID108"
 .table2
 .row &%gnutls_compat_mode%&          "use GnuTLS compatibility mode"

-.new
-.row &%gnutls_enable_pkcs11%&        "allow GnuTLS to autoload PKCS11 modules"
-.wen
+.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 &%openssl_options%&             "adjust OpenSSL compatibility options"
 .row &%tls_advertise_hosts%&         "advertise TLS to these hosts"
 .row &%tls_certificate%&             "location of server certificate"


@@ -13020,12 +13198,10 @@ 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"

-.new
-.row &%dns_use_dnssec%&              "parameter for resolver"
-.wen

 .row &%dns_use_edns0%&               "parameter for resolver"
 .row &%hold_domains%&                "hold delivery for these domains"
 .row &%local_interfaces%&            "for routing checks"
 .row &%dns_use_edns0%&               "parameter for resolver"
 .row &%hold_domains%&                "hold delivery for these domains"
 .row &%local_interfaces%&            "for routing checks"


@@ -13073,6 +13249,8 @@ Those options that undergo string expansion before use are marked with
 .option accept_8bitmime main boolean true
 .cindex "8BITMIME"
 .cindex "8-bit characters"
 .option accept_8bitmime main boolean true
 .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
 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


@@ -13086,6 +13264,11 @@ A more detailed analysis of the issues is provided by Dan Bernstein:
 &url(http://cr.yp.to/smtp/8bitmime.html)
 .endd
 
 &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"
 .cindex "non-SMTP messages" "ACLs for"
 .option acl_not_smtp main string&!! unset
 .cindex "&ACL;" "for non-SMTP messages"
 .cindex "non-SMTP messages" "ACLs for"


@@ -13515,6 +13698,9 @@ 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 "&$domain$&"


@@ -13636,6 +13822,17 @@ 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"


@@ -13666,18 +13863,6 @@ to set in them.
 See &%dns_retrans%& above.
 
 
 See &%dns_retrans%& above.
 
 

-.new
-.option dns_use_dnssec 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.
-.wen
-
-

 .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"


@@ -13903,15 +14088,13 @@ server. This reduces security slightly, but improves interworking with older
 implementations of TLS.
 
 
 implementations of TLS.
 
 

-.new
-option gnutls_enable_pkcs11 main boolean unset
+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
 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.gnu.org/software/gnutls/manual/gnutls.html#Smart-cards-and-HSMs)
+&url(http://www.gnutls.org/manual/gnutls.html#Smart-cards-and-HSMs)

 for documentation.
 for documentation.

-.wen

 
 
 
 
 
 


@@ -14665,6 +14848,8 @@ Possible options may include:
 .next
 &`no_tlsv1_2`&
 .next
 .next
 &`no_tlsv1_2`&
 .next

+&`safari_ecdhe_ecdsa_bug`&
+.next

 &`single_dh_use`&
 .next
 &`single_ecdh_use`&
 &`single_dh_use`&
 .next
 &`single_ecdh_use`&


@@ -14680,6 +14865,13 @@ Possible options may include:
 &`tls_rollback_bug`&
 .endlist
 
 &`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"


@@ -15249,6 +15441,13 @@ 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.

+. 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
 
 .option "smtp_accept_max_per_connection" main integer 1000 &&&
          smtp_accept_max_per_connection


@@ -15300,10 +15499,9 @@ 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"


@@ -15943,6 +16141,21 @@ The available primes are:
 Some of these will be too small to be accepted by clients.
 Some may be too large to be accepted by clients.
 
 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_on_connect_ports main "string list" unset
 This option specifies a list of incoming SSMTP (aka SMTPS) ports that should
 
 .option tls_on_connect_ports main "string list" unset
 This option specifies a list of incoming SSMTP (aka SMTPS) ports that should


@@ -16010,6 +16223,9 @@ use OpenSSL with a directory.
 
 See &<<SECTtlssni>>& for discussion of when this option might be re-expanded.
 
 
 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
 .cindex "TLS" "client certificate verification"
 
 .option tls_verify_hosts main "host list&!!" unset
 .cindex "TLS" "client certificate verification"


@@ -16376,7 +16592,8 @@ be specified using &%condition%&.
 .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


@@ -16385,6 +16602,7 @@ 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.

 
 
 
 
 
 


@@ -17221,7 +17439,8 @@ 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


@@ -17235,7 +17454,8 @@ 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.


@@ -18591,7 +18811,6 @@ 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.
 

-.new

 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
 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


@@ -18601,7 +18820,6 @@ 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.
 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.

-.wen

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


@@ -19543,7 +19761,8 @@ 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"


@@ -19592,7 +19811,6 @@ Unlike most options, &%headers_add%& can be specified multiple times
 for a transport; all listed headers are added.
 
 
 for a transport; all listed headers are added.
 
 

-

 .option headers_only transports boolean false
 .cindex "transport" "header lines only"
 .cindex "message" "transporting headers only"
 .option headers_only transports boolean false
 .cindex "transport" "header lines only"
 .cindex "message" "transporting headers only"


@@ -21536,10 +21754,10 @@ 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
 
 


@@ -21647,6 +21865,15 @@ 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


@@ -21799,6 +22026,23 @@ 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.


@@ -22296,7 +22540,6 @@ See the &%search_parents%& option in chapter &<<CHAPdnslookup>>& for more
 details.
 
 
 details.
 
 

-.new

 .option dscp smtp string&!! unset
 .cindex "DCSP" "outbound"
 This option causes the DSCP value associated with a socket to be set to one
 .option dscp smtp string&!! unset
 .cindex "DCSP" "outbound"
 This option causes the DSCP value associated with a socket to be set to one


@@ -22310,7 +22553,6 @@ The outbound packets from Exim will be marked with this value in the header
 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.
 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.

-.wen

 
 
 .option fallback_hosts smtp "string list" unset
 
 
 .option fallback_hosts smtp "string list" unset


@@ -22716,7 +22958,6 @@ 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.
 
 

-.new

 .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
 .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


@@ -22726,7 +22967,6 @@ If the parameter offered by the server is too small, then the TLS handshake
 will fail.
 
 Only supported when using GnuTLS.
 will fail.
 
 Only supported when using GnuTLS.

-.wen

 
 
 .option tls_privatekey smtp string&!! unset
 
 
 .option tls_privatekey smtp string&!! unset


@@ -22787,6 +23027,14 @@ unknown state), opens a new one to the same host, and then tries the delivery
 in clear.
 
 
 in clear.
 
 

+.option tls_try_verify_hosts smtp "host list&!! unset
+.cindex "TLS" "server certificate verification"
+.cindex "certificate" "verification of server"
+For OpenSSL only, 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.
+
+

 .option tls_verify_certificates smtp string&!! unset
 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 .option tls_verify_certificates smtp string&!! unset
 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"


@@ -22801,6 +23049,20 @@ single file if you are using GnuTLS. 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, or when GnuTLS is used,
+if neither tls_verify_hosts nor tls_try_verify_hosts are 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"
+For OpenSSL only, 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.
+

 
 
 
 
 
 


@@ -23427,7 +23689,7 @@ 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


@@ -24037,6 +24299,12 @@ client_condition = ${if !eq{$tls_out_cipher}{}}
 .endd
 
 
 .endd
 
 

+.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
 This option must always be set. It specifies which of the available
 authenticators is to be used.
 .option driver authenticators string unset
 This option must always be set. It specifies which of the available
 authenticators is to be used.


@@ -24404,7 +24672,7 @@ 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.


@@ -25280,12 +25548,10 @@ option).
 The &%tls_require_ciphers%& options operate differently, as described in the
 sections &<<SECTreqciphssl>>& and &<<SECTreqciphgnu>>&.
 .next
 The &%tls_require_ciphers%& options operate differently, as described in the
 sections &<<SECTreqciphssl>>& and &<<SECTreqciphgnu>>&.
 .next

-.new

 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).
 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).

-.wen

 .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
 .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


@@ -25468,10 +25734,10 @@ 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
 
 Documentation of the strings accepted may be found in the GnuTLS manual, under
 "Priority strings".  This is online as

-&url(http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html),
+&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,
 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.gnu.org/software/gnutls/manual/html_node/Listing-the-ciphersuites-in-a-priority-string.html, then the example code)
+&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.
 
 Prior to Exim 4.80, an older API of GnuTLS was used, and Exim supported three
 on that site can be used to test a given string.
 
 Prior to Exim 4.80, an older API of GnuTLS was used, and Exim supported three


@@ -25557,7 +25823,7 @@ tls_dhparam = none
 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
 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

-documetnation for &%tls_dhparam%& for the complete list.
+documentation for &%tls_dhparam%& for the complete list.

 
 See the command
 .code
 
 See the command
 .code


@@ -25698,6 +25964,12 @@ for OpenSSL only (not GnuTLS), a directory, that contains a collection of
 expected server certificates. 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%&.
 expected server certificates. 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%&.

+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.

 
 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


@@ -25875,6 +26147,12 @@ 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"
 
 .section "Self-signed certificates" "SECID187"
 .cindex "certificate" "self-signed"


@@ -26108,6 +26386,8 @@ 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 both 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


@@ -26117,13 +26397,17 @@ 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 QUIT ACL" "SECTQUITACL"
 .cindex "QUIT, ACL for"
 
 .section "The QUIT ACL" "SECTQUITACL"
 .cindex "QUIT, ACL for"


@@ -26154,7 +26438,7 @@ 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.


@@ -26508,8 +26792,8 @@ 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


@@ -26951,13 +27235,33 @@ 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
+

 
 
 
 
 
 


@@ -27017,15 +27321,25 @@ 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.
 
 

-.new

 .vitem &*control&~=&~cutthrough_delivery*&
 .cindex "&ACL;" "cutthrough routing"
 .vitem &*control&~=&~cutthrough_delivery*&
 .cindex "&ACL;" "cutthrough routing"

+.cindex "cutthrough" "requesting"

 This option requests delivery be attempted while the item is being received.
 It is usable in the RCPT ACL and valid only for single-recipient mails forwarded
 from one SMTP connection to another.  If a recipient-verify callout connection is
 requested in the same ACL it is held open and used for the data, otherwise one is made
 after the ACL completes.
 
 This option requests delivery be attempted while the item is being received.
 It is usable in the RCPT ACL and valid only for single-recipient mails forwarded
 from one SMTP connection to another.  If a recipient-verify callout connection is
 requested in the same ACL it is held open and used for the data, otherwise one is made
 after the 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.
+

 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
 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


@@ -27035,26 +27349,6 @@ 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.
 
 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.

-.wen
-
-
-.new
-.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.
-.wen

 
 
 .vitem &*control&~=&~debug/*&<&'options'&>
 
 
 .vitem &*control&~=&~debug/*&<&'options'&>


@@ -27075,6 +27369,30 @@ 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"


@@ -27265,7 +27583,7 @@ 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


@@ -27274,13 +27592,18 @@ 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.


@@ -27298,7 +27621,9 @@ 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


@@ -27307,7 +27632,9 @@ 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`&


@@ -27356,6 +27683,79 @@ 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"


@@ -27388,8 +27788,10 @@ 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
 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 in $acl_arg1 to $acl_arg9, and $acl_narg is set
-to the count of values.  The name and values are expanded separately.
+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.

 
 If the nested &%acl%& returns &"drop"& and the outer condition denies access,
 the connection is dropped. If it returns &"discard"&, the verb must be
 
 If the nested &%acl%& returns &"drop"& and the outer condition denies access,
 the connection is dropped. If it returns &"discard"&, the verb must be


@@ -27479,7 +27881,7 @@ 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"


@@ -27621,6 +28023,23 @@ 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>>&.
 

+.new
+.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.
+.wen
+

 .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"


@@ -28232,6 +28651,13 @@ 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"


@@ -28613,6 +29039,7 @@ 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


@@ -28634,6 +29061,9 @@ 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


@@ -29276,7 +29706,9 @@ 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
 .vitem &%aveserver%&
 
 .vlist
 .vitem &%aveserver%&


@@ -29302,6 +29734,7 @@ 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


@@ -29310,6 +29743,22 @@ 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.
 


@@ -29394,6 +29843,24 @@ 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.


@@ -33404,6 +33871,7 @@ 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


@@ -33503,6 +33971,11 @@ 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


@@ -33518,6 +33991,12 @@ 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 &">"&.
 


@@ -33610,7 +34089,7 @@ 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


@@ -33628,6 +34107,7 @@ 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


@@ -33694,6 +34174,7 @@ 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


@@ -33726,6 +34207,7 @@ selection marked by asterisks:
 &`*smtp_confirmation          `&  SMTP confirmation on => lines
 &` smtp_connection            `&  SMTP connections
 &` smtp_incomplete_transaction`&  incomplete SMTP transactions
 &`*smtp_confirmation          `&  SMTP confirmation on => lines
 &` 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
 &` smtp_no_mail               `&  session with no MAIL commands
 &` smtp_protocol_error        `&  SMTP protocol errors
 &` smtp_syntax_error          `&  SMTP syntax errors


@@ -33741,6 +34223,14 @@ 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


@@ -33927,7 +34417,8 @@ 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.


@@ -33986,6 +34477,11 @@ 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


@@ -34157,14 +34653,14 @@ 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.


@@ -35388,6 +35884,85 @@ 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"


@@ -35845,7 +36420,7 @@ unqualified domain &'foundation'&.
 . ////////////////////////////////////////////////////////////////////////////
 . ////////////////////////////////////////////////////////////////////////////
 
 . ////////////////////////////////////////////////////////////////////////////
 . ////////////////////////////////////////////////////////////////////////////
 

-.chapter "Support for DKIM (DomainKeys Identified Mail)" "CHID12" &&&
+.chapter "Support for DKIM (DomainKeys Identified Mail)" "CHAPdkim" &&&

          "DKIM Support"
 .cindex "DKIM"
 
          "DKIM Support"
 .cindex "DKIM"
 


@@ -35860,7 +36435,9 @@ 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.
 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


@@ -35951,6 +36528,10 @@ 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


@@ -36065,7 +36646,7 @@ 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


@@ -36096,7 +36677,7 @@ 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
+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
 to restrict an ACL verb to a list of verification outcomes, for example:
 
 .code


@@ -36142,6 +36723,12 @@ 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.