maildir_tag hint provided by Heiko Schlittermann.

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

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 578485ddd5af95a329c421c55834af69b2642f73..34205b4f4c260800656bdf65da58a09312c585bf 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -47,8 +47,8 @@
 . the <bookinfo> element must also be updated for each new edition.
 . /////////////////////////////////////////////////////////////////////////////
 
 . the <bookinfo> element must also be updated for each new edition.
 . /////////////////////////////////////////////////////////////////////////////
 

-.set previousversion "4.71"
-.set version "4.72"
+.set previousversion "4.72"
+.set version "4.74"

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


@@ -172,15 +172,15 @@
 <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>29 May 2010</date>
+<date>21 Jan 2011</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>4.72</revnumber>
-  <date>29 May 2010</date>
+  <revnumber>4.74</revnumber>
+  <date>21 Jan 2011</date>

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

-<copyright><year>2009</year><holder>University of Cambridge</holder></copyright>
+<copyright><year>2011</year><holder>University of Cambridge</holder></copyright>

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


@@ -366,6 +366,7 @@ contributors.
 
 .section "Exim documentation" "SECID1"
 . Keep this example change bar when updating the documentation!
 
 .section "Exim documentation" "SECID1"
 . Keep this example change bar when updating the documentation!

+

 .new
 .cindex "documentation"
 This edition of the Exim specification applies to version &version; of Exim.
 .new
 .cindex "documentation"
 This edition of the Exim specification applies to version &version; of Exim.


@@ -1540,18 +1541,18 @@ is on a file system where the user is over quota. Exim can be configured to
 impose its own quotas on local mailboxes; where system quotas are set they will
 also apply.
 
 impose its own quotas on local mailboxes; where system quotas are set they will
 also apply.
 

+.new

 If a host is unreachable for a period of time, a number of messages may be
 waiting for it by the time it recovers, and sending them in a single SMTP
 connection is clearly beneficial. Whenever a delivery to a remote host is
 deferred,
 If a host is unreachable for a period of time, a number of messages may be
 waiting for it by the time it recovers, and sending them in a single SMTP
 connection is clearly beneficial. Whenever a delivery to a remote host is
 deferred,

-

 .cindex "hints database"
 Exim makes a note in its hints database, and whenever a successful
 SMTP delivery has happened, it looks to see if any other messages are waiting
 for the same host. If any are found, they are sent over the same SMTP
 connection, subject to a configuration limit as to the maximum number in any
 one connection.
 .cindex "hints database"
 Exim makes a note in its hints database, and whenever a successful
 SMTP delivery has happened, it looks to see if any other messages are waiting
 for the same host. If any are found, they are sent over the same SMTP
 connection, subject to a configuration limit as to the maximum number in any
 one connection.

-
+.wen

 
 
 
 
 
 


@@ -1893,7 +1894,9 @@ given in chapter &<<CHAPTLS>>&.
 
 
 
 
 
 

+.new

 .section "Use of tcpwrappers" "SECID27"
 .section "Use of tcpwrappers" "SECID27"

+

 .cindex "tcpwrappers, building Exim to support"
 .cindex "USE_TCP_WRAPPERS"
 .cindex "TCP_WRAPPERS_DAEMON_NAME"
 .cindex "tcpwrappers, building Exim to support"
 .cindex "USE_TCP_WRAPPERS"
 .cindex "TCP_WRAPPERS_DAEMON_NAME"


@@ -1924,7 +1927,7 @@ can be changed at build time by setting TCP_WRAPPERS_DAEMON_NAME in
 in &_Local/Makefile_&, or by setting tcp_wrappers_daemon_name in the
 configure file. Consult the &'tcpwrappers'& documentation for
 further details.
 in &_Local/Makefile_&, or by setting tcp_wrappers_daemon_name in the
 configure file. Consult the &'tcpwrappers'& documentation for
 further details.

-
+.wen

 
 
 .section "Including support for IPv6" "SECID28"
 
 
 .section "Including support for IPv6" "SECID28"


@@ -1946,6 +1949,37 @@ support has not been tested for some time.
 
 
 
 
 
 

+.new
+.section "Dynamically loaded lookup module support" "SECTdynamicmodules"
+.cindex "lookup modules"
+.cindex "dynamic modules"
+.cindex ".so building"
+On some platforms, Exim supports not compiling all lookup types directly into
+the main binary, instead putting some into external modules which can be loaded
+on demand.
+This permits packagers to build Exim with support for lookups with extensive
+library dependencies without requiring all users to install all of those
+dependencies.
+Most, but not all, lookup types can be built this way.
+
+Set &`LOOKUP_MODULE_DIR`& to the directory into which the modules will be
+installed; Exim will only load modules from that directory, as a security
+measure.  You will need to set &`CFLAGS_DYNAMIC`& if not already defined
+for your OS; see &_OS/Makefile-Linux_& for an example.
+Some other requirements for adjusting &`EXTRALIBS`& may also be necessary,
+see &_src/EDITME_& for details.
+
+Then, for each module to be loaded dynamically, define the relevant
+&`LOOKUP_`&<&'lookup_type'&> flags to have the value "2" instead of "yes".
+For example, this will build in lsearch but load sqlite and mysql support
+on demand:
+.code
+LOOKUP_LSEARCH=yes
+LOOKUP_SQLITE=2
+LOOKUP_MYSQL=2
+.endd
+.wen
+

 .section "The building process" "SECID29"
 .cindex "build directory"
 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
 .section "The building process" "SECID29"
 .cindex "build directory"
 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been


@@ -2609,10 +2643,12 @@ This option causes Exim to output a few sentences stating what it is.
 The same output is generated if the Exim binary is called with no options and
 no arguments.
 
 The same output is generated if the Exim binary is called with no options and
 no arguments.
 

+.new

 .vitem &%--version%&
 .oindex "&%--version%&"
 This option is an alias for &%-bV%& and causes version information to be
 displayed.
 .vitem &%--version%&
 .oindex "&%--version%&"
 This option is an alias for &%-bV%& and causes version information to be
 displayed.

+.wen

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


@@ -3179,6 +3215,7 @@ above concerning senders and qualification do not apply. In this situation,
 Exim behaves in exactly the same way as it does when receiving a message via
 the listening daemon.
 
 Exim behaves in exactly the same way as it does when receiving a message via
 the listening daemon.
 

+.new

 .vitem &%-bmalware%&&~<&'filename'&>
 .oindex "&%-bmalware%&"
 .cindex "testing", "malware"
 .vitem &%-bmalware%&&~<&'filename'&>
 .oindex "&%-bmalware%&"
 .cindex "testing", "malware"


@@ -3198,6 +3235,7 @@ This option requires admin privileges.
 The &%-bmalware%& option will not be extended to be more generally useful,
 there are better tools for file-scanning.  This option exists to help
 administrators verify their Exim and AV scanner configuration.
 The &%-bmalware%& option will not be extended to be more generally useful,
 there are better tools for file-scanning.  This option exists to help
 administrators verify their Exim and AV scanner configuration.

+.wen

 
 .vitem &%-bt%&
 .oindex "&%-bt%&"
 
 .vitem &%-bt%&
 .oindex "&%-bt%&"


@@ -3245,15 +3283,16 @@ whose behaviour depends on the contents of an incoming message, you cannot test
 those conditions using &%-bt%&. The &%-N%& option provides a possible way of
 doing such tests.
 
 those conditions using &%-bt%&. The &%-N%& option provides a possible way of
 doing such tests.
 

+.new

 .vitem &%-bV%&
 .oindex "&%-bV%&"
 .cindex "version number of Exim"
 This option causes Exim to write the current version number, compilation
 number, and compilation date of the &'exim'& binary to the standard output.
 .vitem &%-bV%&
 .oindex "&%-bV%&"
 .cindex "version number of Exim"
 This option causes Exim to write the current version number, compilation
 number, and compilation date of the &'exim'& binary to the standard output.

-It also lists the DBM library this is being used, the optional modules (such as
+It also lists the DBM library that is being used, the optional modules (such as

 specific lookup types), the drivers that are included in the binary, and the
 name of the run time configuration file that is in use.
 specific lookup types), the drivers that are included in the binary, and the
 name of the run time configuration file that is in use.

-
+.wen

 As part of its operation, &%-bV%& causes Exim to read and syntax check its
 configuration file. However, this is a static check only. It cannot check
 values that are to be expanded. For example, although a misspelt ACL verb is
 As part of its operation, &%-bV%& causes Exim to read and syntax check its
 configuration file. However, this is a static check only. It cannot check
 values that are to be expanded. For example, although a misspelt ACL verb is


@@ -3331,18 +3370,25 @@ name, but it can be a colon-separated list of names. In this case, the first
 file that exists is used. Failure to open an existing file stops Exim from
 proceeding any further along the list, and an error is generated.
 
 file that exists is used. Failure to open an existing file stops Exim from
 proceeding any further along the list, and an error is generated.
 

+.new

 When this option is used by a caller other than root, and the list is different
 from the compiled-in list, Exim gives up its root privilege immediately, and
 runs with the real and effective uid and gid set to those of the caller.
 When this option is used by a caller other than root, and the list is different
 from the compiled-in list, Exim gives up its root privilege immediately, and
 runs with the real and effective uid and gid set to those of the caller.

-
-This behaviour precludes the possibility of testing a configuration using
-&%-C%& right through message reception and delivery, even if the caller is
-root. The reception works, but by that time, Exim is running as the Exim user,
-so when it re-executes to regain privilege for the delivery, the use of &%-C%&
-causes privilege to be lost. However, root can test reception and delivery
-using two separate commands (one to put a message on the queue, using &%-odq%&,
-and another to do the delivery, using &%-M%&).
-
+However, if a TRUSTED_CONFIG_LIST file is defined in &_Local/Makefile_&, that
+file contains a list of full pathnames, one per line, for configuration files
+which are trusted. Root privilege is retained for any configuration file so
+listed, as long as the caller is the Exim user (or the user specified in the
+CONFIGURE_OWNER option, if any), and as long as the configuration file is
+not writeable by inappropriate users or groups.
+
+Leaving TRUSTED_CONFIG_LIST unset precludes the possibility of testing a
+configuration using &%-C%& right through message reception and delivery,
+even if the caller is root. The reception works, but by that time, Exim is
+running as the Exim user, so when it re-executes to regain privilege for the
+delivery, the use of &%-C%& causes privilege to be lost. However, root can
+test reception and delivery using two separate commands (one to put a message
+on the queue, using &%-odq%&, and another to do the delivery, using &%-M%&).
+.wen

 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
 prefix string with which any file named in a &%-C%& command line option
 must start. In addition, the file name must not contain the sequence &`/../`&.
 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
 prefix string with which any file named in a &%-C%& command line option
 must start. In addition, the file name must not contain the sequence &`/../`&.


@@ -3362,6 +3408,7 @@ caller is privileged, or unless it is an exotic configuration that does not
 require privilege. No check is made on the owner or group of the files
 specified by this option.
 
 require privilege. No check is made on the owner or group of the files
 specified by this option.
 

+

 .vitem &%-D%&<&'macro'&>=<&'value'&>
 .oindex "&%-D%&"
 .cindex "macro" "setting on command line"
 .vitem &%-D%&<&'macro'&>=<&'value'&>
 .oindex "&%-D%&"
 .cindex "macro" "setting on command line"


@@ -3371,6 +3418,15 @@ unprivileged caller, it causes Exim to give up its root privilege.
 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
 completely disabled, and its use causes an immediate error exit.
 
 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
 completely disabled, and its use causes an immediate error exit.
 

+.new
+If WHITELIST_D_MACROS is defined in &_Local/Makefile_& then it should be a
+colon-separated list of macros which are considered safe and, if &%-D%& only
+supplies macros from this list, and the values are acceptable, then Exim will
+not give up root privilege if the caller is root, the Exim run-time user, or
+the CONFIGURE_OWNER, if set.  This is a transition mechanism and is expected
+to be removed in the future.  Acceptable values for the macros satisfy the
+regexp: &`^[A-Za-z0-9_/.-]*$`&
+.wen

 The entire option (including equals sign if present) must all be within one
 command line item. &%-D%& can be used to set the value of a macro to the empty
 string, in which case the equals sign is optional. These two commands are
 The entire option (including equals sign if present) must all be within one
 command line item. &%-D%& can be used to set the value of a macro to the empty
 string, in which case the equals sign is optional. These two commands are


@@ -3387,6 +3443,7 @@ exim '-D ABC = something' ...
 .endd
 &%-D%& may be repeated up to 10 times on a command line.
 
 .endd
 &%-D%& may be repeated up to 10 times on a command line.
 

+

 .vitem &%-d%&<&'debug&~options'&>
 .oindex "&%-d%&"
 .cindex "debugging" "list of selectors"
 .vitem &%-d%&<&'debug&~options'&>
 .oindex "&%-d%&"
 .cindex "debugging" "list of selectors"


@@ -3764,6 +3821,7 @@ by an admin user.
 This option causes the contents of the message body (-D) spool file to be
 written to the standard output. This option can be used only by an admin user.
 
 This option causes the contents of the message body (-D) spool file to be
 written to the standard output. This option can be used only by an admin user.
 

+.new

 .vitem &%-Mvc%&&~<&'message&~id'&>
 .oindex "&%-Mvc%&"
 .cindex "message" "listing in RFC 2822 format"
 .vitem &%-Mvc%&&~<&'message&~id'&>
 .oindex "&%-Mvc%&"
 .cindex "message" "listing in RFC 2822 format"


@@ -3771,7 +3829,7 @@ written to the standard output. This option can be used only by an admin user.
 This option causes a copy of the complete message (header lines plus body) to
 be written to the standard output in RFC 2822 format. This option can be used
 only by an admin user.
 This option causes a copy of the complete message (header lines plus body) to
 be written to the standard output in RFC 2822 format. This option can be used
 only by an admin user.

-
+.wen

 .vitem &%-Mvh%&&~<&'message&~id'&>
 .oindex "&%-Mvh%&"
 .cindex "listing" "message headers"
 .vitem &%-Mvh%&&~<&'message&~id'&>
 .oindex "&%-Mvh%&"
 .cindex "listing" "message headers"


@@ -4486,6 +4544,7 @@ most configurations, this specifies a single file. However, it is permitted to
 give a colon-separated list of file names, in which case Exim uses the first
 existing file in the list.
 
 give a colon-separated list of file names, in which case Exim uses the first
 existing file in the list.
 

+.new

 .cindex "EXIM_USER"
 .cindex "EXIM_GROUP"
 .cindex "CONFIGURE_OWNER"
 .cindex "EXIM_USER"
 .cindex "EXIM_GROUP"
 .cindex "CONFIGURE_OWNER"


@@ -4508,7 +4567,7 @@ Up to Exim version 4.72, the run time configuration file was also permitted to
 be writeable by the Exim user and/or group. That has been changed in Exim 4.73
 since it offered a simple privilege escalation for any attacker who managed to
 compromise the Exim user account.
 be writeable by the Exim user and/or group. That has been changed in Exim 4.73
 since it offered a simple privilege escalation for any attacker who managed to
 compromise the Exim user account.

-
+.wen

 A default configuration file, which will work correctly in simple situations,
 is provided in the file &_src/configure.default_&. If CONFIGURE_FILE
 defines just one file name, the installation process copies the default
 A default configuration file, which will work correctly in simple situations,
 is provided in the file &_src/configure.default_&. If CONFIGURE_FILE
 defines just one file name, the installation process copies the default


@@ -4519,26 +4578,30 @@ configuration.
 
 
 
 
 
 

+.new

 .section "Using a different configuration file" "SECID40"
 .cindex "configuration file" "alternate"
 A one-off alternate configuration can be specified by the &%-C%& command line
 option, which may specify a single file or a list of files. However, when
 &%-C%& is used, Exim gives up its root privilege, unless called by root (or
 unless the argument for &%-C%& is identical to the built-in value from
 .section "Using a different configuration file" "SECID40"
 .cindex "configuration file" "alternate"
 A one-off alternate configuration can be specified by the &%-C%& command line
 option, which may specify a single file or a list of files. However, when
 &%-C%& is used, Exim gives up its root privilege, unless called by root (or
 unless the argument for &%-C%& is identical to the built-in value from

-CONFIGURE_FILE). &%-C%& is useful mainly for checking the syntax of
-configuration files before installing them. No owner or group checks are done
-on a configuration file specified by &%-C%&.
-
-The Exim user is not trusted to specify an arbitrary configuration file with
-the &%-C%& option to be executed with root privileges. This locks out the
-possibility of testing a configuration using &%-C%& right through message
-reception and delivery, even if the caller is root. The reception works, but
-by that time, Exim is running as the Exim user, so when it re-execs to regain
-privilege for the delivery, the use of &%-C%& causes privilege to be lost.
-However, root can test reception and delivery using two separate commands
-(one to put a message on the queue, using &%-odq%&, and another to do the
-delivery, using &%-M%&).
-
+CONFIGURE_FILE), or is listed in the TRUSTED_CONFIG_LIST file and the caller
+is the Exim user or the user specified in the CONFIGURE_OWNER setting. &%-C%&
+is useful mainly for checking the syntax of configuration files before
+installing them. No owner or group checks are done on a configuration file
+specified by &%-C%&, if root privilege has been dropped.
+
+Even the Exim user is not trusted to specify an arbitrary configuration file
+with the &%-C%& option to be used with root privileges, unless that file is
+listed in the TRUSTED_CONFIG_LIST file. This locks out the possibility of
+testing a configuration using &%-C%& right through message reception and
+delivery, even if the caller is root. The reception works, but by that time,
+Exim is running as the Exim user, so when it re-execs to regain privilege for
+the delivery, the use of &%-C%& causes privilege to be lost. However, root
+can test reception and delivery using two separate commands (one to put a
+message on the queue, using &%-odq%&, and another to do the delivery, using
+&%-M%&).
+.wen

 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
 prefix string with which any file named in a &%-C%& command line option must
 start. In addition, the file name must not contain the sequence &"&`/../`&"&.
 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
 prefix string with which any file named in a &%-C%& command line option must
 start. In addition, the file name must not contain the sequence &"&`/../`&"&.


@@ -4552,6 +4615,18 @@ non-privileged user causes Exim to discard its root privilege.
 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
 completely disabled, and its use causes an immediate error exit.
 
 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
 completely disabled, and its use causes an immediate error exit.
 

+.new
+The WHITELIST_D_MACROS option in &_Local/Makefile_& permits the binary builder
+to declare certain macro names trusted, such that root privilege will not
+necessarily be discarded.
+WHITELIST_D_MACROS defines a colon-separated list of macros which are
+considered safe and, if &%-D%& only supplies macros from this list, and the
+values are acceptable, then Exim will not give up root privilege if the caller
+is root, the Exim run-time user, or the CONFIGURE_OWNER, if set.  This is a
+transition mechanism and is expected to be removed in the future.  Acceptable
+values for the macros satisfy the regexp: &`^[A-Za-z0-9_/.-]*$`&
+.wen
+

 Some sites may wish to use the same Exim binary on different machines that
 share a file system, but to use different configuration files on each machine.
 If CONFIGURE_FILE_USE_NODE is defined in &_Local/Makefile_&, Exim first
 Some sites may wish to use the same Exim binary on different machines that
 share a file system, but to use different configuration files on each machine.
 If CONFIGURE_FILE_USE_NODE is defined in &_Local/Makefile_&, Exim first


@@ -6654,7 +6729,6 @@ ${lookup dnsdb{>: a=host1.example}}
 It is permitted to specify a space as the separator character. Further
 white space is ignored.
 
 It is permitted to specify a space as the separator character. Further
 white space is ignored.
 

-.new

 .cindex "TXT record" "in &(dnsdb)& lookup"
 For TXT records with multiple items of data, only the first item is returned,
 unless a separator for them is specified using a comma after the separator
 .cindex "TXT record" "in &(dnsdb)& lookup"
 For TXT records with multiple items of data, only the first item is returned,
 unless a separator for them is specified using a comma after the separator


@@ -6666,7 +6740,6 @@ ${lookup dnsdb{>\n; txt=a.b.example}}
 .endd
 It is permitted to specify a space as the separator character. Further
 white space is ignored.
 .endd
 It is permitted to specify a space as the separator character. Further
 white space is ignored.

-.wen

 
 .section "Pseudo dnsdb record types" "SECID66"
 .cindex "MX record" "in &(dnsdb)& lookup"
 
 .section "Pseudo dnsdb record types" "SECID66"
 .cindex "MX record" "in &(dnsdb)& lookup"


@@ -6812,6 +6885,12 @@ The URL may begin with &`ldap`& or &`ldaps`& if your LDAP library supports
 secure (encrypted) LDAP connections. The second of these ensures that an
 encrypted TLS connection is used.
 
 secure (encrypted) LDAP connections. The second of these ensures that an
 encrypted TLS connection is used.
 

+.new
+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.
+.wen
+

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


@@ -9630,6 +9709,7 @@ srandomdev() or srandom(), or a custom implementation even weaker than
 random().
 
 
 random().
 
 

+.new

 .vitem &*${reverse_ip:*&<&'ipaddr'&>&*}*&
 .cindex "expansion" "IP address"
 This operator reverses an IP address; for IPv4 addresses, the result is in
 .vitem &*${reverse_ip:*&<&'ipaddr'&>&*}*&
 .cindex "expansion" "IP address"
 This operator reverses an IP address; for IPv4 addresses, the result is in


@@ -9643,6 +9723,7 @@ returns
 .code
 4.2.0.192 and 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
 .endd
 .code
 4.2.0.192 and 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
 .endd

+.wen

 
 
 .vitem &*${rfc2047:*&<&'string'&>&*}*&
 
 
 .vitem &*${rfc2047:*&<&'string'&>&*}*&


@@ -9806,6 +9887,8 @@ lower case), signifying multiplication by 1024 or 1024*1024, respectively.
 As a special case, the numerical value of an empty string is taken as
 zero.
 
 As a special case, the numerical value of an empty string is taken as
 zero.
 

+
+.new

 .vitem &*bool&~{*&<&'string'&>&*}*&
 .cindex "expansion" "boolean parsing"
 .cindex "&%bool%& expansion condition"
 .vitem &*bool&~{*&<&'string'&>&*}*&
 .cindex "expansion" "boolean parsing"
 .cindex "&%bool%& expansion condition"


@@ -9821,7 +9904,10 @@ For example:
 .code
 ${if bool{$acl_m_privileged_sender} ...
 .endd
 .code
 ${if bool{$acl_m_privileged_sender} ...
 .endd

+.wen
+

 
 

+.new

 .vitem &*bool_lax&~{*&<&'string'&>&*}*&
 .cindex "expansion" "boolean parsing"
 .cindex "&%bool_lax%& expansion condition"
 .vitem &*bool_lax&~{*&<&'string'&>&*}*&
 .cindex "expansion" "boolean parsing"
 .cindex "&%bool_lax%& expansion condition"


@@ -9832,7 +9918,7 @@ and the values &"false"&, &"no"& and &"0"& map to false, all others map to
 true.  Leading and trailing whitespace is ignored.
 
 Note that where &"bool{00}"& is false, &"bool_lax{00}"& is true.
 true.  Leading and trailing whitespace is ignored.
 
 Note that where &"bool{00}"& is false, &"bool_lax{00}"& is true.

-
+.wen

 .vitem &*crypteq&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&
 .cindex "expansion" "encrypted comparison"
 .cindex "encrypted strings, comparing"
 .vitem &*crypteq&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&
 .cindex "expansion" "encrypted comparison"
 .cindex "encrypted strings, comparing"


@@ -11051,8 +11137,17 @@ number of lines received. Before delivery happens (that is, before filters,
 routers, and transports run) the count is increased to include the
 &'Received:'& header line that Exim standardly adds, and also any other header
 lines that are added by ACLs. The blank line that separates the message header
 routers, and transports run) the count is increased to include the
 &'Received:'& header line that Exim standardly adds, and also any other header
 lines that are added by ACLs. The blank line that separates the message header

-from the body is not counted. Here is an example of the use of this variable in
-a DATA ACL:
+from the body is not counted.
+
+.new
+As with the special case of &$message_size$&, during the expansion of the
+appendfile transport's maildir_tag option in maildir format, the value of
+&$message_linecount$& is the precise size of the number of newlines in the
+file that has been written (minus one for the blank line between the
+header and the body).
+.wen
+
+Here is an example of the use of this variable in a DATA ACL:

 .code
 deny message   = Too many lines in message header
      condition = \
 .code
 deny message   = Too many lines in message header
      condition = \


@@ -12313,7 +12408,14 @@ listed in more than one group.
 .section "Data lookups" "SECID101"
 .table2
 .row &%ibase_servers%&               "InterBase servers"
 .section "Data lookups" "SECID101"
 .table2
 .row &%ibase_servers%&               "InterBase servers"

+.row &%ldap_ca_cert_dir%&            "dir of CA certs to verify LDAP server's"
+.row &%ldap_ca_cert_file%&           "file of CA certs to verify LDAP server's"
+.row &%ldap_cert_file%&              "client cert file for LDAP"
+.row &%ldap_cert_key%&               "client key file for LDAP"
+.row &%ldap_cipher_suite%&           "TLS negotiation preference control"

 .row &%ldap_default_servers%&        "used if no server in query"
 .row &%ldap_default_servers%&        "used if no server in query"

+.row &%ldap_require_cert%&           "action to take without LDAP server cert"
+.row &%ldap_start_tls%&              "require TLS within LDAP"

 .row &%ldap_version%&                "set protocol version"
 .row &%lookup_open_max%&             "lookup files held open"
 .row &%mysql_servers%&               "default MySQL servers"
 .row &%ldap_version%&                "set protocol version"
 .row &%lookup_open_max%&             "lookup files held open"
 .row &%mysql_servers%&               "default MySQL servers"


@@ -12845,6 +12947,7 @@ saying &"keep on trying, even though there are big problems"&.
 &%ignore_bounce_errors_after%&. It is retained for compatibility, but it is not
 thought to be very useful any more, and its use should probably be avoided.
 
 &%ignore_bounce_errors_after%&. It is retained for compatibility, but it is not
 thought to be very useful any more, and its use should probably be avoided.
 

+.new

 .option av_scanner main string "see below"
 This option is available if Exim is built with the content-scanning extension.
 It specifies which anti-virus scanner to use. The default value is:
 .option av_scanner main string "see below"
 This option is available if Exim is built with the content-scanning extension.
 It specifies which anti-virus scanner to use. The default value is:


@@ -12853,7 +12956,7 @@ sophie:/var/run/sophie
 .endd
 If the value of &%av_scanner%& starts with a dollar character, it is expanded
 before use. See section &<<SECTscanvirus>>& for further details.
 .endd
 If the value of &%av_scanner%& starts with a dollar character, it is expanded
 before use. See section &<<SECTscanvirus>>& for further details.

-
+.wen

 
 
 .option bi_command main string unset
 
 
 .option bi_command main string unset


@@ -13724,6 +13827,56 @@ next attempt to deliver such a message, it gets removed. The incident is
 logged.
 
 
 logged.
 
 

+.new
+.option ldap_ca_cert_dir main string unset
+.cindex "LDAP", "TLS CA certificate directory"
+This option indicates which directory contains CA certificates for verifying
+a TLS certificate presented by an LDAP server.
+While Exim does not provide a default value, your SSL library may.
+Analogous to &%tls_verify_certificates%& but as a client-side option for LDAP
+and constrained to be a directory.
+.wen
+
+
+.new
+.option ldap_ca_cert_file main string unset
+.cindex "LDAP", "TLS CA certificate file"
+This option indicates which file contains CA certificates for verifying
+a TLS certificate presented by an LDAP server.
+While Exim does not provide a default value, your SSL library may.
+Analogous to &%tls_verify_certificates%& but as a client-side option for LDAP
+and constrained to be a file.
+.wen
+
+
+.new
+.option ldap_cert_file main string unset
+.cindex "LDAP" "TLS client certificate file"
+This option indicates which file contains an TLS client certificate which
+Exim should present to the LDAP server during TLS negotiation.
+Should be used together with &%ldap_cert_key%&.
+.wen
+
+
+.new
+.option ldap_cert_key main string unset
+.cindex "LDAP" "TLS client key file"
+This option indicates which file contains the secret/private key to use
+to prove identity to the LDAP server during TLS negotiation.
+Should be used together with &%ldap_cert_file%&, which contains the
+identity to be proven.
+.wen
+
+
+.new
+.option ldap_cipher_suite main string unset
+.cindex "LDAP" "TLS cipher suite"
+This controls the TLS cipher-suite negotiation during TLS negotiation with
+the LDAP server.  See &<<SECTreqciphssl>>& for more details of the format of
+cipher-suite options with OpenSSL (as used by LDAP client libraries).
+.wen
+
+

 .option ldap_default_servers main "string list" unset
 .cindex "LDAP" "default servers"
 This option provides a list of LDAP servers which are tried in turn when an
 .option ldap_default_servers main "string list" unset
 .cindex "LDAP" "default servers"
 This option provides a list of LDAP servers which are tried in turn when an


@@ -13732,6 +13885,29 @@ details of LDAP queries. This option is available only when Exim has been built
 with LDAP support.
 
 
 with LDAP support.
 
 

+.new
+.option ldap_require_cert main string unset.
+.cindex "LDAP" "policy for LDAP server TLS cert presentation"
+This should be one of the values "hard", "demand", "allow", "try" or "never".
+A value other than one of these is interpreted as "never".
+See the entry "TLS_REQCERT" in your system man page for ldap.conf(5).
+Although Exim does not set a default, the LDAP library probably defaults
+to hard/demand.
+.wen
+
+
+.new
+.option ldap_start_tls main boolean false
+.cindex "LDAP" "whether or not to negotiate TLS"
+If set, Exim will attempt to negotiate TLS with the LDAP server when
+connecting on a regular LDAP port.  This is the LDAP equivalent of SMTP's
+"STARTTLS".  This is distinct from using "ldaps", which is the LDAP form
+of SSL-on-connect.
+In the event of failure to negotiate TLS, the action taken is controlled
+by &%ldap_require_cert%&.
+.wen
+
+

 .option ldap_version main integer unset
 .cindex "LDAP" "protocol version, forcing"
 This option can be used to force Exim to set a specific protocol version for
 .option ldap_version main integer unset
 .cindex "LDAP" "protocol version, forcing"
 This option can be used to force Exim to set a specific protocol version for


@@ -14005,6 +14181,7 @@ an oversized message is logged in both the main and the reject logs. See also
 the generic transport option &%message_size_limit%&, which limits the size of
 message that an individual transport can process.
 
 the generic transport option &%message_size_limit%&, which limits the size of
 message that an individual transport can process.
 

+.new

 If you use a virus-scanner and set this option to to a value larger than the
 maximum size that your virus-scanner is configured to support, you may get
 failures triggered by large mails.  The right size to configure for the
 If you use a virus-scanner and set this option to to a value larger than the
 maximum size that your virus-scanner is configured to support, you may get
 failures triggered by large mails.  The right size to configure for the


@@ -14012,6 +14189,7 @@ virus-scanner depends upon what data is passed and the options in use but it's
 probably safest to just set it to a little larger than this value.  Eg, with a
 default Exim message size of 50M and a default ClamAV StreamMaxLength of 10M,
 some problems may result.
 probably safest to just set it to a little larger than this value.  Eg, with a
 default Exim message size of 50M and a default ClamAV StreamMaxLength of 10M,
 some problems may result.

+.wen

 
 
 .option move_frozen_messages main boolean false
 
 
 .option move_frozen_messages main boolean false


@@ -14065,6 +14243,7 @@ harm. This option overrides the &%pipe_as_creator%& option of the &(pipe)&
 transport driver.
 
 
 transport driver.
 
 

+.new

 .option openssl_options main "string list" +dont_insert_empty_fragments
 .cindex "OpenSSL "compatibility options"
 This option allows an administrator to adjust the SSL options applied
 .option openssl_options main "string list" +dont_insert_empty_fragments
 .cindex "OpenSSL "compatibility options"
 This option allows an administrator to adjust the SSL options applied


@@ -14093,6 +14272,7 @@ An example:
 .code
 openssl_options = -all +microsoft_big_sslv3_buffer
 .endd
 .code
 openssl_options = -all +microsoft_big_sslv3_buffer
 .endd

+.wen

 
 
 .option oracle_servers main "string list" unset
 
 
 .option oracle_servers main "string list" unset


@@ -15195,11 +15375,13 @@ contains the pipe command.
 This specifies the transport driver that is to be used when a &%mail%& command
 is used in a system filter.
 
 This specifies the transport driver that is to be used when a &%mail%& command
 is used in a system filter.
 

+.new

 .option system_filter_user main string unset
 .cindex "uid (user id)" "system filter"
 .option system_filter_user main string unset
 .cindex "uid (user id)" "system filter"

-If this option is not set, the system filter is run in the main Exim delivery
-process, as root. When the option is set, the system filter runs in a separate
-process, as the given user. Unless the string consists entirely of digits, it
+If this option is set to root, the system filter is run in the main Exim
+delivery process, as root.  Otherwise, the system filter runs in a separate
+process, as the given user, defaulting to the Exim run-time user.
+Unless the string consists entirely of digits, it

 is looked up in the password data. Failure to find the named user causes a
 configuration error. The gid is either taken from the password data, or
 specified by &%system_filter_group%&. When the uid is specified numerically,
 is looked up in the password data. Failure to find the named user causes a
 configuration error. The gid is either taken from the password data, or
 specified by &%system_filter_group%&. When the uid is specified numerically,


@@ -15207,8 +15389,8 @@ specified by &%system_filter_group%&. When the uid is specified numerically,
 
 If the system filter generates any pipe, file, or reply deliveries, the uid
 under which the filter is run is used when transporting them, unless a
 
 If the system filter generates any pipe, file, or reply deliveries, the uid
 under which the filter is run is used when transporting them, unless a

-transport option overrides. Normally you should set &%system_filter_user%& if
-your system filter generates these kinds of delivery.
+transport option overrides.
+.wen

 
 
 .option tcp_nodelay main boolean true
 
 
 .option tcp_nodelay main boolean true


@@ -15353,6 +15535,14 @@ are using OpenSSL, you can set &%tls_verify_certificates%& to the name of a
 directory containing certificate files. This does not work with GnuTLS; the
 option must be set to the name of a single file if you are using GnuTLS.
 
 directory containing certificate files. This does not work with GnuTLS; the
 option must be set to the name of a single file if you are using GnuTLS.
 

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

 
 .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"


@@ -15690,9 +15880,12 @@ router is skipped, and the address is offered to the next one.
 If the result is any other value, the router is run (as this is the last
 precondition to be evaluated, all the other preconditions must be true).
 
 If the result is any other value, the router is run (as this is the last
 precondition to be evaluated, all the other preconditions must be true).
 

+.new

 This option is unique in that multiple &%condition%& options may be present.
 All &%condition%& options must succeed.
 This option is unique in that multiple &%condition%& options may be present.
 All &%condition%& options must succeed.

+.wen

 
 

+.new

 The &%condition%& option provides a means of applying custom conditions to the
 running of routers. Note that in the case of a simple conditional expansion,
 the default expansion values are exactly what is wanted. For example:
 The &%condition%& option provides a means of applying custom conditions to the
 running of routers. Note that in the case of a simple conditional expansion,
 the default expansion values are exactly what is wanted. For example:


@@ -15703,16 +15896,18 @@ Because of the default behaviour of the string expansion, this is equivalent to
 .code
 condition = ${if >{$message_age}{600}{true}{}}
 .endd
 .code
 condition = ${if >{$message_age}{600}{true}{}}
 .endd

+

 A multiple condition example, which succeeds:
 .code
 condition = ${if >{$message_age}{600}}
 condition = ${if !eq{${lc:$local_part}}{postmaster}}
 condition = foobar
 .endd
 A multiple condition example, which succeeds:
 .code
 condition = ${if >{$message_age}{600}}
 condition = ${if !eq{${lc:$local_part}}{postmaster}}
 condition = foobar
 .endd

+

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

-
+.wen

 
 
 .option debug_print routers string&!! unset
 
 
 .option debug_print routers string&!! unset


@@ -19997,6 +20192,7 @@ The regular expression should not assume that the length is at the end of the
 file name (even though &%maildir_tag%& puts it there) because maildir MUAs
 sometimes add other information onto the ends of message file names.
 
 file name (even though &%maildir_tag%& puts it there) because maildir MUAs
 sometimes add other information onto the ends of message file names.
 

+Section &<<SECID136>>& contains further information.

 
 
 .option quota_warn_message appendfile string&!! "see below"
 
 
 .option quota_warn_message appendfile string&!! "see below"


@@ -20411,6 +20607,7 @@ tag is added to its name. However, if adding the tag takes the length of the
 name to the point where the test &[stat()]& call fails with ENAMETOOLONG,
 the tag is dropped and the maildir file is created with no tag.
 
 name to the point where the test &[stat()]& call fails with ENAMETOOLONG,
 the tag is dropped and the maildir file is created with no tag.
 

+.new

 .vindex "&$message_size$&"
 Tags can be used to encode the size of files in their names; see
 &%quota_size_regex%& above for an example. The expansion of &%maildir_tag%&
 .vindex "&$message_size$&"
 Tags can be used to encode the size of files in their names; see
 &%quota_size_regex%& above for an example. The expansion of &%maildir_tag%&


@@ -20420,8 +20617,20 @@ forced to fail, the tag is ignored, but a non-forced failure causes delivery to
 be deferred. The expanded tag may contain any printing characters except &"/"&.
 Non-printing characters in the string are ignored; if the resulting string is
 empty, it is ignored. If it starts with an alphanumeric character, a leading
 be deferred. The expanded tag may contain any printing characters except &"/"&.
 Non-printing characters in the string are ignored; if the resulting string is
 empty, it is ignored. If it starts with an alphanumeric character, a leading

-colon is inserted.
+colon is inserted; this default has not proven to be the path that popular
+maildir implementations have chosen (but changing it in Exim would break
+backwards compatibility).

 
 

+For one common implementation, you might set:
+.code
+maildir_tag = ,S=${message_size}
+.endd
+but you should check the documentation of the other software to be sure.
+
+It is advisable to also set &%quota_size_regex%& when setting &%maildir_tag%&
+as this allows Exim to extract the size from your tag, instead of having to
+&[stat()]& each message file.
+.wen

 
 
 .section "Using a maildirsize file" "SECID136"
 
 
 .section "Using a maildirsize file" "SECID136"


@@ -20847,9 +21056,14 @@ later"&. In this case, delivery is deferred. Details of a permanent failure are
 logged, but are not included in the bounce message, which merely contains
 &"local delivery failed"&.
 
 logged, but are not included in the bounce message, which merely contains
 &"local delivery failed"&.
 

+If the command exits on a signal and the &%freeze_signal%& option is set then
+the message will be frozen in the queue. If that option is not set, a bounce
+will be sent as normal.
+

 If the return code is greater than 128 and the command being run is a shell
 script, it normally means that the script was terminated by a signal whose
 If the return code is greater than 128 and the command being run is a shell
 script, it normally means that the script was terminated by a signal whose

-value is the return code minus 128.
+value is the return code minus 128. The &%freeze_signal%& option does not
+apply in this case.

 
 If Exim is unable to run the command (that is, if &[execve()]& fails), the
 return code is set to 127. This is the value that a shell returns if it is
 
 If Exim is unable to run the command (that is, if &[execve()]& fails), the
 return code is set to 127. This is the value that a shell returns if it is


@@ -21058,6 +21272,16 @@ is set, failure to exec is treated specially, and causes the message to be
 frozen, whatever the setting of &%ignore_status%&.
 
 
 frozen, whatever the setting of &%ignore_status%&.
 
 

+.new
+.otion freeze_signal pipe boolean false
+.cindex "signal exit"
+.cidenx "&(pipe)& transport", "signal exit"
+Normally if the process run by a command in a pipe transport exits on a signal,
+a bounce message is sent. If &%freeze_signal%& is set, the message will be
+frozen in Exim's queue instead.
+.wen
+
+

 .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.


@@ -21145,6 +21369,7 @@ sought in the PATH directories, in the usual way. &*Warning*&: This does not
 apply to a command specified as a transport filter.
 
 
 apply to a command specified as a transport filter.
 
 

+.new

 .option permit_coredump pipe boolean false
 Normally Exim inhibits core-dumps during delivery.  If you have a need to get
 a core-dump of a pipe command, enable this command.  This enables core-dumps
 .option permit_coredump pipe boolean false
 Normally Exim inhibits core-dumps during delivery.  If you have a need to get
 a core-dump of a pipe command, enable this command.  This enables core-dumps


@@ -21154,6 +21379,7 @@ for it and that this only be enabled when needed, as the risk of excessive
 resource consumption can be quite high.  Note also that Exim is typically
 installed as a setuid binary and most operating systems will inhibit coredumps
 of these by default, so further OS-specific action may be required.
 resource consumption can be quite high.  Note also that Exim is typically
 installed as a setuid binary and most operating systems will inhibit coredumps
 of these by default, so further OS-specific action may be required.

+.wen

 
 
 .option pipe_as_creator pipe boolean false
 
 
 .option pipe_as_creator pipe boolean false


@@ -23688,6 +23914,7 @@ with the AUTH command (in contravention of the specification of LOGIN), but
 if the client does not supply it (as is the case for LOGIN clients), the prompt
 strings are used to obtain two data items.
 
 if the client does not supply it (as is the case for LOGIN clients), the prompt
 strings are used to obtain two data items.
 

+.new

 Some clients are very particular about the precise text of the prompts. For
 example, Outlook Express is reported to recognize only &"Username:"& and
 &"Password:"&. Here is an example of a LOGIN authenticator that uses those
 Some clients are very particular about the precise text of the prompts. For
 example, Outlook Express is reported to recognize only &"Username:"& and
 &"Password:"&. Here is an example of a LOGIN authenticator that uses those


@@ -23698,7 +23925,7 @@ login:
   driver = plaintext
   public_name = LOGIN
   server_prompts = Username:: : Password::
   driver = plaintext
   public_name = LOGIN
   server_prompts = Username:: : Password::

-  server_condition = ${if and{{
+  server_condition = ${if and{{ \

     !eq{}{$auth1} }{ \
     ldapauth{user="cn=${quote_ldap_dn:$auth1},ou=people,o=example.org" \
              pass=${quote:$auth2} \
     !eq{}{$auth1} }{ \
     ldapauth{user="cn=${quote_ldap_dn:$auth1},ou=people,o=example.org" \
              pass=${quote:$auth2} \


@@ -23712,7 +23939,7 @@ operator to correctly quote the DN for authentication. However, the basic
 correct one to use for the password, because quoting is needed only to make
 the password conform to the Exim syntax. At the LDAP level, the password is an
 uninterpreted string.
 correct one to use for the password, because quoting is needed only to make
 the password conform to the Exim syntax. At the LDAP level, the password is an
 uninterpreted string.

-
+.wen

 
 .section "Support for different kinds of authentication" "SECID174"
 A number of string expansion features are provided for the purpose of
 
 .section "Support for different kinds of authentication" "SECID174"
 A number of string expansion features are provided for the purpose of


@@ -24912,6 +25139,19 @@ and try again later, but that is their problem, though it does waste some of
 your resources.
 
 
 your resources.
 
 

+.new
+.section "The SMTP DKIM ACL" "SECTDKIMACL"
+The &%acl_smtp_dkim%& ACL is available only when Exim is compiled with DKIM support
+enabled (which is the default).
+
+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.
+
+For details on the operation of DKIM, see chapter &<<CHID12>>&.
+.wen
+
+

 .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>>&.


@@ -25808,6 +26048,7 @@ warn  control = caseful_local_part
 Notice that we put back the lower cased version afterwards, assuming that
 is what is wanted for subsequent tests.
 
 Notice that we put back the lower cased version afterwards, assuming that
 is what is wanted for subsequent tests.
 

+.new

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


@@ -25824,6 +26065,7 @@ contexts):
       control = debug/opts=+expand+acl
       control = debug/tag=.$message_exim_id/opts=+expand
 .endd
       control = debug/opts=+expand+acl
       control = debug/tag=.$message_exim_id/opts=+expand
 .endd

+.wen

 
 .vitem &*control&~=&~enforce_sync*& &&&
        &*control&~=&~no_enforce_sync*&
 
 .vitem &*control&~=&~enforce_sync*& &&&
        &*control&~=&~no_enforce_sync*&


@@ -27936,6 +28178,7 @@ It supports a &"generic"& interface to scanners called via the shell, and
 specialized interfaces for &"daemon"& type virus scanners, which are resident
 in memory and thus are much faster.
 
 specialized interfaces for &"daemon"& type virus scanners, which are resident
 in memory and thus are much faster.
 

+.new

 .oindex "&%av_scanner%&"
 You can set the &%av_scanner%& option in first part of the Exim configuration
 file to specify which scanner to use, together with any additional options that
 .oindex "&%av_scanner%&"
 You can set the &%av_scanner%& option in first part of the Exim configuration
 file to specify which scanner to use, together with any additional options that


@@ -27949,7 +28192,7 @@ 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:
 .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:

-
+.wen

 .vlist
 .vitem &%aveserver%&
 .cindex "virus scanners" "Kaspersky"
 .vlist
 .vitem &%aveserver%&
 .cindex "virus scanners" "Kaspersky"


@@ -27961,6 +28204,7 @@ example:
 av_scanner = aveserver:/var/run/aveserver
 .endd
 
 av_scanner = aveserver:/var/run/aveserver
 .endd
 

+.new

 .vitem &%clamd%&
 .cindex "virus scanners" "clamd"
 This daemon-type scanner is GPL and free. You can get it at
 .vitem &%clamd%&
 .cindex "virus scanners" "clamd"
 This daemon-type scanner is GPL and free. You can get it at


@@ -27983,7 +28227,7 @@ There is an option WITH_OLD_CLAMAV_STREAM in &_src/EDITME_& available, should
 you be running a version of ClamAV prior to 0.95.
 If the option is unset, the default is &_/tmp/clamd_&. Thanks to David Saez for
 contributing the code for this scanner.
 you be running a version of ClamAV prior to 0.95.
 If the option is unset, the default is &_/tmp/clamd_&. Thanks to David Saez for
 contributing the code for this scanner.

-
+.wen

 .vitem &%cmdline%&
 .cindex "virus scanners" "command line interface"
 This is the keyword for the generic command line scanner interface. It can be
 .vitem &%cmdline%&
 .cindex "virus scanners" "command line interface"
 This is the keyword for the generic command line scanner interface. It can be


@@ -28120,8 +28364,10 @@ If your virus scanner cannot unpack MIME and TNEF containers itself, you should
 use the &%demime%& condition (see section &<<SECTdemimecond>>&) before the
 &%malware%& condition.
 
 use the &%demime%& condition (see section &<<SECTdemimecond>>&) before the
 &%malware%& condition.
 

+.new

 Beware the interaction of Exim's &%message_size_limit%& with any size limits
 imposed by your anti-virus scanner.
 Beware the interaction of Exim's &%message_size_limit%& with any size limits
 imposed by your anti-virus scanner.

+.wen

 
 Here is a very simple scanning example:
 .code
 
 Here is a very simple scanning example:
 .code


@@ -28243,22 +28489,25 @@ SpamAssassin profile has been matched or exceeded. If you want to use the
 &%spam%& condition for its side effects (see the variables below), you can make
 it always return &"true"& by appending &`:true`& to the username.
 
 &%spam%& condition for its side effects (see the variables below), you can make
 it always return &"true"& by appending &`:true`& to the username.
 

+.new

 .cindex "spam scanning" "returned variables"
 When the &%spam%& condition is run, it sets up a number of expansion
 variables. These variables are saved with the received message, thus they are
 available for use at delivery time.
 .cindex "spam scanning" "returned variables"
 When the &%spam%& condition is run, it sets up a number of expansion
 variables. These variables are saved with the received message, thus they are
 available for use at delivery time.

+.wen

 
 .vlist
 .vitem &$spam_score$&
 The spam score of the message, for example &"3.4"& or &"30.5"&. This is useful
 for inclusion in log or reject messages.
 
 
 .vlist
 .vitem &$spam_score$&
 The spam score of the message, for example &"3.4"& or &"30.5"&. This is useful
 for inclusion in log or reject messages.
 

+.new

 .vitem &$spam_score_int$&
 The spam score of the message, multiplied by ten, as an integer value. For
 example &"34"& or &"305"&. It may appear to disagree with &$spam_score$&
 because &$spam_score$& is rounded and &$spam_score_int$& is truncated.
 The integer value is useful for numeric comparisons in conditions.
 .vitem &$spam_score_int$&
 The spam score of the message, multiplied by ten, as an integer value. For
 example &"34"& or &"305"&. It may appear to disagree with &$spam_score$&
 because &$spam_score$& is rounded and &$spam_score_int$& is truncated.
 The integer value is useful for numeric comparisons in conditions.

-
+.wen

 
 .vitem &$spam_bar$&
 A string consisting of a number of &"+"& or &"-"& characters, representing the
 
 .vitem &$spam_bar$&
 A string consisting of a number of &"+"& or &"-"& characters, representing the


@@ -30945,9 +31194,10 @@ rejected (there seems little point) but instead just get qualified. HELO
 and EHLO act as RSET; VRFY, EXPN, ETRN and  HELP, act
 as NOOP; QUIT quits.
 
 and EHLO act as RSET; VRFY, EXPN, ETRN and  HELP, act
 as NOOP; QUIT quits.
 

-No policy checking is done for BSMTP input. That is, no ACL is run at anytime.
-In this respect it is like non-SMTP local input.
-
+.new
+Minimal policy checking is done for BSMTP input. Only the non-SMTP
+ACL is run in the same way as for non-SMTP local input.
+.wen

 If an error is detected while reading a message, including a missing &"."& at
 the end, Exim gives up immediately. It writes details of the error to the
 standard output in a stylized way that the calling program should be able to
 If an error is detected while reading a message, including a missing &"."& at
 the end, Exim gives up immediately. It writes details of the error to the
 standard output in a stylized way that the calling program should be able to


@@ -31883,8 +32133,10 @@ log_file_path = $spool_directory/log/%slog
 If you do not specify anything at build time or run time, that is where the
 logs are written.
 
 If you do not specify anything at build time or run time, that is where the
 logs are written.
 

-A log file path may also contain &`%D`& if datestamped log file names are in
-use &-- see section &<<SECTdatlogfil>>& below.
+.new
+A log file path may also contain &`%D`& or &`%M`& if datestamped log file names
+are in use &-- see section &<<SECTdatlogfil>>& below.
+.wen

 
 Here are some examples of possible settings:
 .display
 
 Here are some examples of possible settings:
 .display


@@ -31924,18 +32176,20 @@ renamed.
 
 
 
 
 
 

+.new

 .section "Datestamped log files" "SECTdatlogfil"
 .cindex "log" "datestamped files"
 Instead of cycling the main and reject log files by renaming them
 periodically, some sites like to use files whose names contain a datestamp,
 .section "Datestamped log files" "SECTdatlogfil"
 .cindex "log" "datestamped files"
 Instead of cycling the main and reject log files by renaming them
 periodically, some sites like to use files whose names contain a datestamp,

-for example, &_mainlog-20031225_&. The datestamp is in the form &_yyyymmdd_&.
-Exim has support for this way of working. It is enabled by setting the
-&%log_file_path%& option to a path that includes &`%D`& at the point where the
-datestamp is required. For example:
+for example, &_mainlog-20031225_&. The datestamp is in the form &_yyyymmdd_& or
+&_yyyymm_&. Exim has support for this way of working. It is enabled by setting
+the &%log_file_path%& option to a path that includes &`%D`& or &`%M`& at the
+point where the datestamp is required. For example:

 .code
 log_file_path = /var/spool/exim/log/%slog-%D
 log_file_path = /var/log/exim-%s-%D.log
 log_file_path = /var/spool/exim/log/%D-%slog
 .code
 log_file_path = /var/spool/exim/log/%slog-%D
 log_file_path = /var/log/exim-%s-%D.log
 log_file_path = /var/spool/exim/log/%D-%slog

+log_file_path = /var/log/exim/%s.%M

 .endd
 As before, &`%s`& is replaced by &"main"& or &"reject"&; the following are
 examples of names generated by the above examples:
 .endd
 As before, &`%s`& is replaced by &"main"& or &"reject"&; the following are
 examples of names generated by the above examples:


@@ -31943,6 +32197,7 @@ examples of names generated by the above examples:
 /var/spool/exim/log/mainlog-20021225
 /var/log/exim-reject-20021225.log
 /var/spool/exim/log/20021225-mainlog
 /var/spool/exim/log/mainlog-20021225
 /var/log/exim-reject-20021225.log
 /var/spool/exim/log/20021225-mainlog

+/var/log/exim/main.200212

 .endd
 When this form of log file is specified, Exim automatically switches to new
 files at midnight. It does not make any attempt to compress old logs; you
 .endd
 When this form of log file is specified, Exim automatically switches to new
 files at midnight. It does not make any attempt to compress old logs; you


@@ -31951,15 +32206,18 @@ run &'exicyclog'& with this form of logging.
 
 The location of the panic log is also determined by &%log_file_path%&, but it
 is not datestamped, because rotation of the panic log does not make sense.
 
 The location of the panic log is also determined by &%log_file_path%&, but it
 is not datestamped, because rotation of the panic log does not make sense.

-When generating the name of the panic log, &`%D`& is removed from the string.
-In addition, if it immediately follows a slash, a following non-alphanumeric
-character is removed; otherwise a preceding non-alphanumeric character is
-removed. Thus, the three examples above would give these panic log names:
+When generating the name of the panic log, &`%D`& or &`%M`& are removed from
+the string. In addition, if it immediately follows a slash, a following
+non-alphanumeric character is removed; otherwise a preceding non-alphanumeric
+character is removed. Thus, the four examples above would give these panic
+log names:

 .code
 /var/spool/exim/log/paniclog
 /var/log/exim-panic.log
 /var/spool/exim/log/paniclog
 .code
 /var/spool/exim/log/paniclog
 /var/log/exim-panic.log
 /var/spool/exim/log/paniclog

+/var/log/exim/panic

 .endd
 .endd

+.wen

 
 
 .section "Logging to syslog" "SECID249"
 
 
 .section "Logging to syslog" "SECID249"


@@ -33792,19 +34050,32 @@ value of the &%-C%& option is identical to the value of CONFIGURE_FILE in
 &_Local/Makefile_&, Exim ignores &%-C%& and proceeds as usual.) There is no
 default setting for &%ALT_CONFIG_PREFIX%&.
 
 &_Local/Makefile_&, Exim ignores &%-C%& and proceeds as usual.) There is no
 default setting for &%ALT_CONFIG_PREFIX%&.
 

+.new

 If the permitted configuration files are confined to a directory to
 which only root has access, this guards against someone who has broken
 into the Exim account from running a privileged Exim with an arbitrary
 configuration file, and using it to break into other accounts.
 .next
 If the permitted configuration files are confined to a directory to
 which only root has access, this guards against someone who has broken
 into the Exim account from running a privileged Exim with an arbitrary
 configuration file, and using it to break into other accounts.
 .next

-If a non-default configuration file is specified with &%-C%&, or macros are
-given with &%-D%&, then root privilege is retained only if the caller of Exim
-is root. This locks out the possibility of testing a configuration using &%-C%&
+
+If a non-trusted configuration file (i.e. not the default configuration file
+or one which is trusted by virtue of being listed in the TRUSTED_CONFIG_LIST
+file) is specified with &%-C%&, or if macros are given with &%-D%& (but see
+the next item), then root privilege is retained only if the caller of Exim is
+root. This locks out the possibility of testing a configuration using &%-C%&

 right through message reception and delivery, even if the caller is root. The
 reception works, but by that time, Exim is running as the Exim user, so when
 it re-execs to regain privilege for the delivery, the use of &%-C%& causes
 privilege to be lost. However, root can test reception and delivery using two
 separate commands.
 right through message reception and delivery, even if the caller is root. The
 reception works, but by that time, Exim is running as the Exim user, so when
 it re-execs to regain privilege for the delivery, the use of &%-C%& causes
 privilege to be lost. However, root can test reception and delivery using two
 separate commands.

+
+.next
+The WHITELIST_D_MACROS build option declares some macros to be safe to override
+with &%-D%& if the real uid is one of root, the Exim run-time user or the
+CONFIGURE_OWNER, if defined.  The potential impact of this option is limited by
+requiring the run-time value supplied to &%-D%& to match a regex that errs on
+the restrictive side.  Requiring build-time selection of safe macros is onerous
+but this option is intended solely as a transition mechanism to permit
+previously-working configurations to continue to work after release 4.73.

 .next
 If DISABLE_D_OPTION is defined, the use of the &%-D%& command line option
 is disabled.
 .next
 If DISABLE_D_OPTION is defined, the use of the &%-D%& command line option
 is disabled.


@@ -33815,7 +34086,7 @@ option, but it cannot be overridden; the runtime option adds additional users
 to the list. The default setting is &"root"&; this prevents a non-root user who
 is permitted to modify the runtime file from using Exim as a way to get root.
 .endlist
 to the list. The default setting is &"root"&; this prevents a non-root user who
 is permitted to modify the runtime file from using Exim as a way to get root.
 .endlist

-
+.wen

 
 
 
 
 
 


@@ -33855,15 +34126,19 @@ abdication; the process cannot regain root afterwards. Prior to release 4.00,
 After a new Exim process has interpreted its command line options, it changes
 uid and gid in the following cases:
 
 After a new Exim process has interpreted its command line options, it changes
 uid and gid in the following cases:
 

+.new

 .ilist
 .oindex "&%-C%&"
 .oindex "&%-D%&"
 If the &%-C%& option is used to specify an alternate configuration file, or if
 the &%-D%& option is used to define macro values for the configuration, and the
 calling process is not running as root, the uid and gid are changed to those of
 .ilist
 .oindex "&%-C%&"
 .oindex "&%-D%&"
 If the &%-C%& option is used to specify an alternate configuration file, or if
 the &%-D%& option is used to define macro values for the configuration, and the
 calling process is not running as root, the uid and gid are changed to those of

- the calling process.
+the calling process.

 However, if DISABLE_D_OPTION is defined in &_Local/Makefile_&, the &%-D%&
 option may not be used at all.
 However, if DISABLE_D_OPTION is defined in &_Local/Makefile_&, the &%-D%&
 option may not be used at all.

+If WHITELIST_D_MACROS is defined in &_Local/Makefile_&, then some macro values
+can be supplied if the calling process is running as root, the Exim run-time
+user or CONFIGURE_OWNER, if defined.

 .next
 .oindex "&%-be%&"
 .oindex "&%-bf%&"
 .next
 .oindex "&%-be%&"
 .oindex "&%-bf%&"


@@ -33885,7 +34160,7 @@ option).
 For a daemon, queue runner, delivery, or address testing process, the uid
 remains as root at this stage, but the gid is changed to the Exim group.
 .endlist
 For a daemon, queue runner, delivery, or address testing process, the uid
 remains as root at this stage, but the gid is changed to the Exim group.
 .endlist

-
+.wen

 The processes that initially retain root privilege behave as follows:
 
 .ilist
 The processes that initially retain root privilege behave as follows:
 
 .ilist


@@ -34120,6 +34395,14 @@ arbitrary program's being run as exim, not as root.
 
 
 
 
 
 

+.new
+.section "Dynamic module directory" "SECTdynmoddir"
+Any dynamically loadable modules must be installed into the directory
+defined in &`LOOKUP_MODULE_DIR`& in &_Local/Makefile_& for Exim to permit
+loading it.
+.wen
+
+

 .section "Use of sprintf()" "SECID279"
 .cindex "&[sprintf()]&"
 A large number of occurrences of &"sprintf"& in the code are actually calls to
 .section "Use of sprintf()" "SECID279"
 .cindex "&[sprintf()]&"
 A large number of occurrences of &"sprintf"& in the code are actually calls to


@@ -34476,6 +34759,7 @@ unqualified domain &'foundation'&.
 Since version 4.70, DKIM support is compiled into Exim by default. It can be
 disabled by setting DISABLE_DKIM=yes in Local/Makefile.
 
 Since version 4.70, DKIM support is compiled into Exim by default. It can be
 disabled by setting DISABLE_DKIM=yes in Local/Makefile.
 

+.new

 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.


@@ -34485,7 +34769,7 @@ Verify signatures in incoming messages: This is implemented by an additional
 ACL (acl_smtp_dkim), which can be called several times per message, with
 different signature contexts.
 .endlist
 ACL (acl_smtp_dkim), which can be called several times per message, with
 different signature contexts.
 .endlist

-
+.wen

 In typical Exim style, the verification implementation does not include any
 default "policy". Instead it enables you to build your own policy using
 Exim's standard controls.
 In typical Exim style, the verification implementation does not include any
 default "policy". Instead it enables you to build your own policy using
 Exim's standard controls.


@@ -34510,6 +34794,7 @@ senders).
 Signing is implemented by setting private options on the SMTP transport.
 These options take (expandable) strings as arguments.
 
 Signing is implemented by setting private options on the SMTP transport.
 These options take (expandable) strings as arguments.
 

+.new

 .option dkim_domain smtp string&!! unset
 MANDATORY:
 The domain you want to sign with. The result of this expanded
 .option dkim_domain smtp string&!! unset
 MANDATORY:
 The domain you want to sign with. The result of this expanded


@@ -34559,7 +34844,7 @@ When set, this option must expand to (or be specified as) a colon-separated
 list of header names. Headers with these names will be included in the message
 signature. When unspecified, the header names recommended in RFC4871 will be
 used.
 list of header names. Headers with these names will be included in the message
 signature. When unspecified, the header names recommended in RFC4871 will be
 used.

-
+.wen

 
 .section "Verifying DKIM signatures in incoming mail" "SECID514"
 .cindex "DKIM" "verification"
 
 .section "Verifying DKIM signatures in incoming mail" "SECID514"
 .cindex "DKIM" "verification"


@@ -34577,6 +34862,7 @@ more advanced policies. For that reason, the global option
 &%dkim_verify_signers%&, and a global expansion variable
 &%$dkim_signers%& exist.
 
 &%dkim_verify_signers%&, and a global expansion variable
 &%$dkim_signers%& exist.
 

+.new

 The global option &%dkim_verify_signers%& can be set to a colon-separated
 list of DKIM domains or identities for which the ACL &%acl_smtp_dkim%& is
 called. It is expanded when the message has been received. At this point,
 The global option &%dkim_verify_signers%& can be set to a colon-separated
 list of DKIM domains or identities for which the ACL &%acl_smtp_dkim%& is
 called. It is expanded when the message has been received. At this point,


@@ -34599,7 +34885,7 @@ You can also be more creative in constructing your policy. For example:
 .code
 dkim_verify_signers = $sender_address_domain:$dkim_signers
 .endd
 .code
 dkim_verify_signers = $sender_address_domain:$dkim_signers
 .endd

-
+.wen

 If a domain or identity is listed several times in the (expanded) value of
 &%dkim_verify_signers%&, the ACL is only called once for that domain or identity.
 
 If a domain or identity is listed several times in the (expanded) value of
 &%dkim_verify_signers%&, the ACL is only called once for that domain or identity.
 


@@ -34607,6 +34893,7 @@ If a domain or identity is listed several times in the (expanded) value of
 Inside the &%acl_smtp_dkim%&, the following expansion variables are
 available (from most to least important):
 
 Inside the &%acl_smtp_dkim%&, the following expansion variables are
 available (from most to least important):
 

+.new

 .vlist
 .vitem &%$dkim_cur_signer%&
 The signer that is being evaluated in this ACL run. This can be a domain or
 .vlist
 .vitem &%$dkim_cur_signer%&
 The signer that is being evaluated in this ACL run. This can be a domain or


@@ -34691,16 +34978,17 @@ in the key record.
 .vitem &%$dkim_key_notes%&
 Notes from the key record (tag n=).
 .endlist
 .vitem &%$dkim_key_notes%&
 Notes from the key record (tag n=).
 .endlist

-
+.wen

 In addition, two ACL conditions are provided:
 
 In addition, two ACL conditions are provided:
 

+.new

 .vlist
 .vitem &%dkim_signers%&
 ACL condition that checks a colon-separated list of domains or identities
 for a match against the domain or identity that the ACL is currently verifying
 (reflected by &%$dkim_cur_signer%&). This is typically used to restrict an ACL
 verb to a group of domains or identities. For example:
 .vlist
 .vitem &%dkim_signers%&
 ACL condition that checks a colon-separated list of domains or identities
 for a match against the domain or identity that the ACL is currently verifying
 (reflected by &%$dkim_cur_signer%&). This is typically used to restrict an ACL
 verb to a group of domains or identities. For example:

-
+.wen

 .code
 # Warn when message apparently from GMail has no signature at all
 warn log_message = GMail sender without DKIM signature
 .code
 # Warn when message apparently from GMail has no signature at all
 warn log_message = GMail sender without DKIM signature