Add 2-ph note to process info

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

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index ee6fc5c370bf836500b2fdcb09ee5c912f962c6e..f3bf5ea8ebcaa136edfc5579b877c9d937aafa1f 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -1,4 +1,3 @@
-

 . /////////////////////////////////////////////////////////////////////////////
 . This is the primary source of the Exim Manual. It is an xfpt document that is
 . converted into DocBook XML for subsequent conversion into printable and online
 . /////////////////////////////////////////////////////////////////////////////
 . This is the primary source of the Exim Manual. It is an xfpt document that is
 . converted into DocBook XML for subsequent conversion into printable and online


@@ -46,7 +45,7 @@
 . Update the Copyright year (only) when changing content.
 . /////////////////////////////////////////////////////////////////////////////
 
 . Update the Copyright year (only) when changing content.
 . /////////////////////////////////////////////////////////////////////////////
 

-.set previousversion "4.96"
+.set previousversion "4.98"

 .include ./local_params
 
 .set ACL "access control lists (ACLs)"
 .include ./local_params
 
 .set ACL "access control lists (ACLs)"


@@ -55,7 +54,7 @@
 .set drivernamemax "64"
 
 .macro copyyear
 .set drivernamemax "64"
 
 .macro copyyear

-2022
+2024

 .endmacro
 
 . /////////////////////////////////////////////////////////////////////////////
 .endmacro
 
 . /////////////////////////////////////////////////////////////////////////////


@@ -996,12 +995,9 @@ contains the number of seconds since the start of the epoch (the normal Unix
 way of representing the date and time of day).
 .next
 After the first hyphen, the next
 way of representing the date and time of day).
 .next
 After the first hyphen, the next

-.new

 eleven
 eleven

-.wen

 characters are the id of the process that received the message.
 .next
 characters are the id of the process that received the message.
 .next

-.new

 There are two different possibilities for the final four characters:
 .olist
 .oindex "&%localhost_number%&"
 There are two different possibilities for the final four characters:
 .olist
 .oindex "&%localhost_number%&"


@@ -1017,7 +1013,6 @@ If &%localhost_number%& is set, it is multiplied by
 500000 (250000) and added to
 the fractional part of the time, which in this case is in units of 2 us (4 us).
 .endlist
 500000 (250000) and added to
 the fractional part of the time, which in this case is in units of 2 us (4 us).
 .endlist

-.wen

 .endlist
 
 After a message has been received, Exim waits for the clock to tick at the
 .endlist
 
 After a message has been received, Exim waits for the clock to tick at the


@@ -1769,6 +1764,12 @@ distributors have chosen to bundle different libraries with their packaged
 versions. However, the more recent releases seem to have standardized on the
 Berkeley DB library.
 
 versions. However, the more recent releases seem to have standardized on the
 Berkeley DB library.
 

+.new
+Ownership of the Berkeley DB library has moved to a major corporation;
+development seems to have stalled and documentation is not freely available.
+This is probably not tenable for the long term use by Exim.
+.wen
+

 Different DBM libraries have different conventions for naming the files they
 use. When a program opens a file called &_dbmfile_&, there are several
 possibilities:
 Different DBM libraries have different conventions for naming the files they
 use. When a program opens a file called &_dbmfile_&, there are several
 possibilities:


@@ -1809,6 +1810,9 @@ suited to Exim's usage model.
 Yet another DBM library, called &'tdb'&, is available from
 &url(https://sourceforge.net/projects/tdb/files/). It has its own interface, and also
 operates on a single file.
 Yet another DBM library, called &'tdb'&, is available from
 &url(https://sourceforge.net/projects/tdb/files/). It has its own interface, and also
 operates on a single file.

+.next
+It is possible to use sqlite3 (&url(https://www.sqlite.org/index.html))
+for the DBM library.

 .endlist
 
 .cindex "USE_DB"
 .endlist
 
 .cindex "USE_DB"


@@ -1820,8 +1824,9 @@ USE_DB in an appropriate configuration file (typically
 .code
 USE_DB=yes
 .endd
 .code
 USE_DB=yes
 .endd

-Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An
-error is diagnosed if you set more than one of these.
+Similarly, for gdbm you set USE_GDBM, for tdb you set USE_TDB,
+and for sqlite3 you set USE_SQLITE.
+An error is diagnosed if you set more than one of these.

 You can set USE_NDBM if needed to override an operating system default.
 
 At the lowest level, the build-time configuration sets none of these options,
 You can set USE_NDBM if needed to override an operating system default.
 
 At the lowest level, the build-time configuration sets none of these options,


@@ -1837,6 +1842,7 @@ in one of these lines:
 .code
 DBMLIB = -ldb
 DBMLIB = -ltdb
 .code
 DBMLIB = -ldb
 DBMLIB = -ltdb

+DBMLIB = -lsqlite3

 DBMLIB = -lgdbm -lgdbm_compat
 .endd
 The last of those was for a Linux having GDBM provide emulated NDBM facilities.
 DBMLIB = -lgdbm -lgdbm_compat
 .endd
 The last of those was for a Linux having GDBM provide emulated NDBM facilities.


@@ -1852,6 +1858,17 @@ DBMLIB=/usr/local/lib/db-4.1/libdb.a
 There is further detailed discussion about the various DBM libraries in the
 file &_doc/dbm.discuss.txt_& in the Exim distribution.
 
 There is further detailed discussion about the various DBM libraries in the
 file &_doc/dbm.discuss.txt_& in the Exim distribution.
 

+.new
+When moving from one DBM library to another,
+for the hints databases it suffices to just remove all the files in the
+directory named &"db/"& under the spool directory.
+This is because hints are only for optimisation and will be rebuilt
+during normal operations.
+Non-hints DBM databases (used by &"dbm"& lookups in the configuration)
+will need individual rebuilds for the new DBM library.
+This is not done automatically
+.wen
+

 
 
 .section "Pre-building configuration" "SECID25"
 
 
 .section "Pre-building configuration" "SECID25"


@@ -2052,19 +2069,29 @@ withdrawn.
 
 
 
 
 
 

-.section "Dynamically loaded lookup module support" "SECTdynamicmodules"
+.section "Dynamically loaded module support" "SECTdynamicmodules"

 .cindex "lookup modules"
 .cindex "lookup modules"

+.cindex "router modules"
+.cindex "transport modules"
+.cindex "authenticator 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
 .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
+library dependencies without requiring all systems to install all of those

 dependencies.
 dependencies.

-Most, but not all, lookup types can be built this way.
+.new
+Any combination of lookup types can be built this way.
+Lookup types that provide several variants will be loaded as
+Exim starts.
+Types that provide only one method are not loaded until used by
+the runtime configuration.
+.wen

 
 

-Set &`LOOKUP_MODULE_DIR`& to the directory into which the modules will be
+For building
+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.
 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.


@@ -2074,12 +2101,25 @@ 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
 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:
+only if each is installed:

 .code
 LOOKUP_LSEARCH=yes
 LOOKUP_SQLITE=2
 LOOKUP_MYSQL=2
 .endd
 .code
 LOOKUP_LSEARCH=yes
 LOOKUP_SQLITE=2
 LOOKUP_MYSQL=2
 .endd

+Set also &`LOOKUP_`&<&'lookup_type'&>&` INCLUDE`& and
+&`LOOKUP_`&<&'lookup_type'&>`_LIBS if needed for each lookup type,
+ensuring that duplicates are not present in more global values.
+
+.new
+Similarly, authenticator, router and transport drivers can be built
+as external modules.
+Modules will be searched for as demanded by the runtime configuration,
+permitting a smaller Exim binary.
+
+For building, as above but using
+&`AUTH_*`&, &`ROUTER_*`& and &`TRANSPORT_*`& instead of &`LOOKUP_*`&,
+.wen

 
 
 .section "The building process" "SECID29"
 
 
 .section "The building process" "SECID29"


@@ -2846,13 +2886,11 @@ of Exim is installed. It is not necessary to do this when other files that are
 referenced from the configuration (for example, alias files) are changed,
 because these are reread each time they are used.
 
 referenced from the configuration (for example, alias files) are changed,
 because these are reread each time they are used.
 

-.new

 Either a SIGTERM or a SIGINT signal should be used to cause the daemon
 to cleanly shut down.
 Subprocesses handling recceiving or delivering messages,
 or for scanning the queue,
 will not be affected by the termination of the daemon process.
 Either a SIGTERM or a SIGINT signal should be used to cause the daemon
 to cleanly shut down.
 Subprocesses handling recceiving or delivering messages,
 or for scanning the queue,
 will not be affected by the termination of the daemon process.

-.wen

 
 .cmdopt -bdf
 This option has the same effect as &%-bd%& except that it never disconnects
 
 .cmdopt -bdf
 This option has the same effect as &%-bd%& except that it never disconnects


@@ -2890,11 +2928,12 @@ defined and macros will be expanded.
 Because macros in the config file are often used for secrets, those are only
 available to admin users.
 
 Because macros in the config file are often used for secrets, those are only
 available to admin users.
 

-.new

 The word &"set"& at the start of a line, followed by a single space,
 is recognised specially as defining a value for a variable.
 The word &"set"& at the start of a line, followed by a single space,
 is recognised specially as defining a value for a variable.

+.cindex "tainted data" "expansion testing"
+If the sequence &",t"& is inserted before the space,
+the value is marked as tainted.

 The syntax is otherwise the same as the ACL modifier &"set ="&.
 The syntax is otherwise the same as the ACL modifier &"set ="&.

-.wen

 
 .cmdopt -bem <&'filename'&>
 .cindex "testing" "string expansion"
 
 .cmdopt -bem <&'filename'&>
 .cindex "testing" "string expansion"


@@ -3104,7 +3143,7 @@ options, as appropriate. The &%-bnq%& option (see below) provides a way of
 suppressing this for special cases.
 
 Policy checks on the contents of local messages can be enforced by means of
 suppressing this for special cases.
 
 Policy checks on the contents of local messages can be enforced by means of

-the non-SMTP ACL. See chapter &<<CHAPACL>>& for details.
+the non-SMTP ACL. See section &<<SECnonSMTP>>& for details.

 
 .cindex "return code" "for &%-bm%&"
 The return code is zero if the message is successfully accepted. Otherwise, the
 
 .cindex "return code" "for &%-bm%&"
 The return code is zero if the message is successfully accepted. Otherwise, the


@@ -3380,7 +3419,7 @@ dots doubled), terminated by a line containing just a single dot. An error is
 provoked if the terminating dot is missing. A further message may then follow.
 
 As for other local message submissions, the contents of incoming batch SMTP
 provoked if the terminating dot is missing. A further message may then follow.
 
 As for other local message submissions, the contents of incoming batch SMTP

-messages can be checked using the non-SMTP ACL (see chapter &<<CHAPACL>>&).
+messages can be checked using the non-SMTP ACL (see section &<<SECnonSMTP>>&).

 Unqualified addresses are automatically qualified using &%qualify_domain%& and
 &%qualify_recipient%&, as appropriate, unless the &%-bnq%& option is used.
 
 Unqualified addresses are automatically qualified using &%qualify_domain%& and
 &%qualify_recipient%&, as appropriate, unless the &%-bnq%& option is used.
 


@@ -4450,7 +4489,6 @@ It is only relevant when the &%-bd%& (start listening daemon) option is also
 given.
 Normally the daemon creates this socket, unless a &%-oX%& and &*no*& &%-oP%&
 option is also present.
 given.
 Normally the daemon creates this socket, unless a &%-oX%& and &*no*& &%-oP%&
 option is also present.

-.new

 If this option is given then the socket will not be created.  This is required
 if the system is running multiple daemons, in which case it should
 be used on all.
 If this option is given then the socket will not be created.  This is required
 if the system is running multiple daemons, in which case it should
 be used on all.


@@ -4464,7 +4502,6 @@ caching compiled regexes
 .next
 obtaining a current queue size
 .endlist
 .next
 obtaining a current queue size
 .endlist

-.wen

 
 .cmdopt -pd
 .cindex "Perl" "starting the interpreter"
 
 .cmdopt -pd
 .cindex "Perl" "starting the interpreter"


@@ -4569,12 +4606,10 @@ delivered down a single SMTP
 .cindex "multiple SMTP deliveries"
 connection because of the hints that were set up during the first queue scan.
 
 .cindex "multiple SMTP deliveries"
 connection because of the hints that were set up during the first queue scan.
 

-.new

 Two-phase queue runs should be used on systems which, even intermittently,
 have a large queue (such as mailing-list operators).
 They may also be useful for hosts that are connected to the Internet
 intermittently.
 Two-phase queue runs should be used on systems which, even intermittently,
 have a large queue (such as mailing-list operators).
 They may also be useful for hosts that are connected to the Internet
 intermittently.

-.wen

 
 .vitem &%-q[q]i...%&
 .oindex "&%-qi%&"
 
 .vitem &%-q[q]i...%&
 .oindex "&%-qi%&"


@@ -4660,14 +4695,12 @@ combined daemon at system boot time is to use a command such as
 Such a daemon listens for incoming SMTP calls, and also starts a queue runner
 process every 30 minutes.
 
 Such a daemon listens for incoming SMTP calls, and also starts a queue runner
 process every 30 minutes.
 

-.new

 .cindex "named queues" "queue runners"
 It is possible to set up runners for multiple named queues within one daemon,
 For example:
 .code
 exim -qGhipri/2m -q10m -qqGmailinglist/1h
 .endd
 .cindex "named queues" "queue runners"
 It is possible to set up runners for multiple named queues within one daemon,
 For example:
 .code
 exim -qGhipri/2m -q10m -qqGmailinglist/1h
 .endd

-.wen

 
 When a daemon is started by &%-q%& with a time value, but without &%-bd%&, no
 pid file is written unless one is explicitly requested by the &%-oP%& option.
 
 When a daemon is started by &%-q%& with a time value, but without &%-bd%&, no
 pid file is written unless one is explicitly requested by the &%-oP%& option.


@@ -4724,7 +4757,7 @@ all selected messages, not just the first; frozen messages are included when
 
 The &%-R%& option makes it straightforward to initiate delivery of all messages
 to a given domain after a host has been down for some time. When the SMTP
 
 The &%-R%& option makes it straightforward to initiate delivery of all messages
 to a given domain after a host has been down for some time. When the SMTP

-command ETRN is accepted by its ACL (see chapter &<<CHAPACL>>&), its default
+command ETRN is accepted by its ACL (see section &<<SECTETRN>>&), its default

 effect is to run Exim with the &%-R%& option, but it can be configured to run
 an arbitrary command instead.
 
 effect is to run Exim with the &%-R%& option, but it can be configured to run
 an arbitrary command instead.
 


@@ -5442,7 +5475,7 @@ list items, it is not ignored when parsing the list. The spaces around the first
 colon in the example above are necessary. If they were not there, the list would
 be interpreted as the two items 127.0.0.1:: and 1.
 
 colon in the example above are necessary. If they were not there, the list would
 be interpreted as the two items 127.0.0.1:: and 1.
 

-.section "Changing list separators" "SECTlistsepchange"
+.subsection "Changing list separators" "SECTlistsepchange"

 .cindex "list separator" "changing"
 .cindex "IPv6" "addresses in lists"
 Doubling colons in IPv6 addresses is an unwelcome chore, so a mechanism was
 .cindex "list separator" "changing"
 .cindex "IPv6" "addresses in lists"
 Doubling colons in IPv6 addresses is an unwelcome chore, so a mechanism was


@@ -5483,7 +5516,7 @@ enclosing an empty list item.
 
 
 
 
 
 

-.section "Empty items in lists" "SECTempitelis"
+.subsection "Empty items in lists" "SECTempitelis"

 .cindex "list" "empty item in"
 An empty item at the end of a list is always ignored. In other words, trailing
 separator characters are ignored. Thus, the list in
 .cindex "list" "empty item in"
 An empty item at the end of a list is always ignored. In other words, trailing
 separator characters are ignored. Thus, the list in


@@ -6756,11 +6789,11 @@ Exim variables you need to construct the database query.
 
 For the string-expansion kind of lookups, the query is given in the first
 bracketed argument of the &${lookup ...}$& expansion.
 
 For the string-expansion kind of lookups, the query is given in the first
 bracketed argument of the &${lookup ...}$& expansion.

-For the list-argument kind of lookup the quury is given by the remainder of the
+For the list-argument kind of lookup the query is given by the remainder of the

 list item after the first semicolon.
 
 .cindex "tainted data" "quoting for lookups"
 list item after the first semicolon.
 
 .cindex "tainted data" "quoting for lookups"

-If tainted data is used in the query then it should be quuted by
+If tainted data is used in the query then it should be quoted by

 using the &*${quote_*&<&'lookup-type'&>&*:*&<&'string'&>&*}*& expansion operator
 appropriate for the lookup.
 .endlist
 using the &*${quote_*&<&'lookup-type'&>&*:*&<&'string'&>&*}*& expansion operator
 appropriate for the lookup.
 .endlist


@@ -6855,7 +6888,8 @@ by default, but has an option to omit them (see section &<<SECTdbmbuild>>&).
 .cindex "dsearch lookup type"
 The given file must be an absolute directory path; this is searched for an entry
 whose name is the key by calling the &[lstat()]& function.
 .cindex "dsearch lookup type"
 The given file must be an absolute directory path; this is searched for an entry
 whose name is the key by calling the &[lstat()]& function.

-The key may not contain any forward slash characters.
+Unless the options (below) permit a path,
+the key may not contain any forward slash characters.

 If &[lstat()]& succeeds then so does the lookup.
 .cindex "tainted data" "dsearch result"
 The result is regarded as untainted.
 If &[lstat()]& succeeds then so does the lookup.
 .cindex "tainted data" "dsearch result"
 The result is regarded as untainted.


@@ -6864,7 +6898,7 @@ Options for the lookup can be given by appending them after the word "dsearch",
 separated by a comma.  Options, if present, are a comma-separated list having
 each element starting with a tag name and an equals.
 
 separated by a comma.  Options, if present, are a comma-separated list having
 each element starting with a tag name and an equals.
 

-Two options are supported, for the return value and for filtering match
+Three options are supported, for the return value and for filtering match

 candidates.
 The "ret" option requests an alternate result value of
 the entire path for the entry. Example:
 candidates.
 The "ret" option requests an alternate result value of
 the entire path for the entry. Example:


@@ -6872,6 +6906,7 @@ the entire path for the entry. Example:
 ${lookup {passwd} dsearch,ret=full {/etc}}
 .endd
 The default result is just the requested entry.
 ${lookup {passwd} dsearch,ret=full {/etc}}
 .endd
 The default result is just the requested entry.

+

 The "filter" option requests that only directory entries of a given type
 are matched. The match value is one of "file", "dir" or "subdir" (the latter
 not matching "." or ".."). Example:
 The "filter" option requests that only directory entries of a given type
 are matched. The match value is one of "file", "dir" or "subdir" (the latter
 not matching "." or ".."). Example:


@@ -6881,6 +6916,14 @@ ${lookup {passwd} dsearch,filter=file {/etc}}
 The default matching is for any entry type, including directories
 and symlinks.
 
 The default matching is for any entry type, including directories
 and symlinks.
 

+The "key" option relaxes the restriction that only a simple path component can
+be searched for, to permit a sequence of path components. Example:
+.code
+${lookup {foo/bar} dsearch,key=path {/etc}}
+.endd
+If this option is used, a ".." component in the key is specifically disallowed.
+The default operation is that the key may only be a single path component.
+

 An example of how this
 lookup can be used to support virtual domains is given in section
 &<<SECTvirtualdomains>>&.
 An example of how this
 lookup can be used to support virtual domains is given in section
 &<<SECTvirtualdomains>>&.


@@ -6910,8 +6953,8 @@ key is found. The first key that matches is used; there is no attempt to find a
 lookup types support only literal keys.
 
 &*Warning 2*&: In a host list, you must always use &(net-iplsearch)& so that
 lookup types support only literal keys.
 
 &*Warning 2*&: In a host list, you must always use &(net-iplsearch)& so that

-the implicit key is the host's IP address rather than its name (see section
-&<<SECThoslispatsikey>>&).
+the implicit key is the host's IP address rather than its name
+(see section &<<SECThoslispatsikey>>&).

 
 &*Warning 3*&: Do not use an IPv4-mapped IPv6 address for a key; use the
 IPv4, in dotted-quad form. (Exim converts IPv4-mapped IPv6 addresses to this
 
 &*Warning 3*&: Do not use an IPv4-mapped IPv6 address for a key; use the
 IPv4, in dotted-quad form. (Exim converts IPv4-mapped IPv6 addresses to this


@@ -7409,10 +7452,8 @@ For example, the way to write the NIS+ query is
 [name="${quote_nisplus:$local_part}"]
 .endd
 .cindex "tainted data" "in lookups"
 [name="${quote_nisplus:$local_part}"]
 .endd
 .cindex "tainted data" "in lookups"

-.new

 &*All*& tainted data used in a query-style lookup must be quoted
 using a mechanism appropriate for the lookup type.
 &*All*& tainted data used in a query-style lookup must be quoted
 using a mechanism appropriate for the lookup type.

-.wen

 See chapter &<<CHAPexpand>>& for full coverage of string expansions. The quote
 operator can be used for all lookup types, but has no effect for single-key
 lookups, since no quoting is ever needed in their key strings.
 See chapter &<<CHAPexpand>>& for full coverage of string expansions. The quote
 operator can be used for all lookup types, but has no effect for single-key
 lookups, since no quoting is ever needed in their key strings.


@@ -8172,13 +8213,18 @@ option, you can still update it by a query of this form:
 ${lookup pgsql,servers=master/db/name/pw {UPDATE ...} }
 .endd
 
 ${lookup pgsql,servers=master/db/name/pw {UPDATE ...} }
 .endd
 

-An older syntax places the servers specification before the query,
+A now-deprecated syntax places the servers specification before the query,

 semicolon separated:
 .code
 ${lookup mysql{servers=master; UPDATE ...} }
 .endd
 semicolon separated:
 .code
 ${lookup mysql{servers=master; UPDATE ...} }
 .endd

-The new version avoids potential issues with tainted
-arguments in the query, for explicit expansion.
+The new version avoids issues with tainted
+arguments explicitly expanded as part of the query.
+The entire string within the braces becomes tainted,
+including the server specification - which is not permissible.
+If the older sytax is used, a warning message will be logged.
+This syntax will be removed in a future release.
+

 &*Note*&: server specifications in list-style lookups are still problematic.
 
 
 &*Note*&: server specifications in list-style lookups are still problematic.
 
 


@@ -8206,6 +8252,9 @@ or delete command), the result of the lookup is the number of rows affected.
 anything (for example, setting a field to the value it already has), the result
 is zero because no rows are affected.
 
 anything (for example, setting a field to the value it already has), the result
 is zero because no rows are affected.
 

+To get an encryted connection, use a Mysql option file with the required
+parameters for the connection.
+

 
 .subsection "Special PostgreSQL features" SECID74
 PostgreSQL lookups can also use Unix domain socket connections to the database.
 
 .subsection "Special PostgreSQL features" SECID74
 PostgreSQL lookups can also use Unix domain socket connections to the database.


@@ -8355,6 +8404,9 @@ type of match and is given below as the &*value*& information.
 .section "Expansion of lists" "SECTlistexpand"
 .cindex "expansion" "of lists"
 Each list is expanded as a single string before it is used.
 .section "Expansion of lists" "SECTlistexpand"
 .cindex "expansion" "of lists"
 Each list is expanded as a single string before it is used.

+.cindex "tainted data" tracking
+&*Note*&: As a result, if any componend was tainted then the
+entire result string becomes tainted.

 
 &'Exception: the router headers_remove option, where list-item
 splitting is done before string-expansion.'&
 
 &'Exception: the router headers_remove option, where list-item
 splitting is done before string-expansion.'&


@@ -9236,8 +9288,9 @@ is not used.
 
 &*Reminder*&: With this kind of pattern, you must have host &'names'& as
 keys in the file, not IP addresses. If you want to do lookups based on IP
 
 &*Reminder*&: With this kind of pattern, you must have host &'names'& as
 keys in the file, not IP addresses. If you want to do lookups based on IP

-addresses, you must precede the search type with &"net-"& (see section
-&<<SECThoslispatsikey>>&). There is, however, no reason why you could not use
+addresses, you must precede the search type with &"net-"&
+(see section &<<SECThoslispatsikey>>&).
+There is, however, no reason why you could not use

 two items in the same list, one doing an address lookup and one doing a name
 lookup, both using the same file.
 
 two items in the same list, one doing an address lookup and one doing a name
 lookup, both using the same file.
 


@@ -9550,6 +9603,9 @@ start of a portion of the string that is interpreted and replaced as described
 below in section &<<SECTexpansionitems>>& onwards. Backslash is used as an
 escape character, as described in the following section.
 
 below in section &<<SECTexpansionitems>>& onwards. Backslash is used as an
 escape character, as described in the following section.
 

+.cindex "tainted data" tracking
+If any porttion of the result string is tainted, the entire result is.
+

 Whether a string is expanded depends upon the context.  Usually this is solely
 dependent upon the option for which a value is sought; in this documentation,
 options for which string expansion is performed are marked with &dagger; after
 Whether a string is expanded depends upon the context.  Usually this is solely
 dependent upon the option for which a value is sought; in this documentation,
 options for which string expansion is performed are marked with &dagger; after


@@ -9622,7 +9678,6 @@ value. Nevertheless the &%-be%& option can be useful for checking out file and
 database lookups, and the use of expansion operators such as &%sg%&, &%substr%&
 and &%nhash%&.
 
 database lookups, and the use of expansion operators such as &%sg%&, &%substr%&
 and &%nhash%&.
 

-.new

 When reading lines from the standard input,
 macros can be defined and ACL variables can be set.
 For example:
 When reading lines from the standard input,
 macros can be defined and ACL variables can be set.
 For example:


@@ -9631,7 +9686,6 @@ MY_MACRO = foo
 set acl_m_myvar = bar
 .endd
 Such macros and variables can then be used in later input lines.
 set acl_m_myvar = bar
 .endd
 Such macros and variables can then be used in later input lines.

-.wen

 
 Exim gives up its root privilege when it is called with the &%-be%& option, and
 instead runs under the uid and gid it was called with, to prevent users from
 
 Exim gives up its root privilege when it is called with the &%-be%& option, and
 instead runs under the uid and gid it was called with, to prevent users from


@@ -9748,9 +9802,7 @@ Example use (as an ACL modifier):
       add_header = :at_start:${authresults {$primary_hostname}}
 .endd
 This is safe even if no authentication results are available
       add_header = :at_start:${authresults {$primary_hostname}}
 .endd
 This is safe even if no authentication results are available

-.new

 and would generally be placed in the DATA ACL.
 and would generally be placed in the DATA ACL.

-.wen

 
 
 .vitem "&*${certextract{*&<&'field'&>&*}{*&<&'certificate'&>&*}&&&
 
 
 .vitem "&*${certextract{*&<&'field'&>&*}{*&<&'certificate'&>&*}&&&


@@ -10010,9 +10062,7 @@ default, but the separator can be changed in the usual way (&<<SECTlistsepchange
 For each item
 in this list, its value is placed in &$item$&, and then the condition is
 evaluated.
 For each item
 in this list, its value is placed in &$item$&, and then the condition is
 evaluated.

-.new

 Any modification of &$value$& by this evaluation is discarded.
 Any modification of &$value$& by this evaluation is discarded.

-.wen

 If the condition is true, &$item$& is added to the output as an
 item in a new list; if the condition is false, the item is discarded. The
 separator used for the output list is the same as the one used for the
 If the condition is true, &$item$& is added to the output as an
 item in a new list; if the condition is false, the item is discarded. The
 separator used for the output list is the same as the one used for the


@@ -10633,7 +10683,7 @@ expansion items.
 This item inserts &"raw"& header lines. It is described with the &%header%&
 expansion item in section &<<SECTexpansionitems>>& above.
 
 This item inserts &"raw"& header lines. It is described with the &%header%&
 expansion item in section &<<SECTexpansionitems>>& above.
 

-.vitem "&*${run<&'options'&> {*&<&'command&~arg&~list'&>&*}{*&<&'string1'&>&*}&&&
+.vitem "&*${run<&'options'&> {*&<&'command&~string'&>&*}{*&<&'string1'&>&*}&&&

         {*&<&'string2'&>&*}}*&"
 .cindex "expansion" "running a command"
 .cindex "&%run%& expansion item"
         {*&<&'string2'&>&*}}*&"
 .cindex "expansion" "running a command"
 .cindex "&%run%& expansion item"


@@ -10642,8 +10692,8 @@ One option is supported after the word &'run'&, comma-separated
 and without whitespace.
 
 If the option &'preexpand'& is not used,
 and without whitespace.
 
 If the option &'preexpand'& is not used,

-the command string is split into individual arguments by spaces
-and then each argument is expanded.
+the command string before expansion is split into individual arguments by spaces
+and then each argument is separately expanded.

 Then the command is run
 in a separate process, but under the same uid and gid.  As in other command
 executions from Exim, a shell is not used by default. If the command requires
 Then the command is run
 in a separate process, but under the same uid and gid.  As in other command
 executions from Exim, a shell is not used by default. If the command requires


@@ -10655,9 +10705,9 @@ potential attacker;
 a careful assessment for security vulnerabilities should be done.
 
 If the option &'preexpand'& is used,
 a careful assessment for security vulnerabilities should be done.
 
 If the option &'preexpand'& is used,

-the command and its arguments are first expanded as one string. The result is
-split apart into individual arguments by spaces, and then the command is run
-as above.
+the command string is first expanded as a whole.
+The expansion result is split apart into individual arguments by spaces,
+and then the command is run as above.

 Since the arguments are split by spaces, when there is a variable expansion
 which has an empty result, it will cause the situation that the argument will
 simply be omitted when the program is actually executed by Exim. If the
 Since the arguments are split by spaces, when there is a variable expansion
 which has an empty result, it will cause the situation that the argument will
 simply be omitted when the program is actually executed by Exim. If the


@@ -10783,7 +10833,7 @@ will sort an MX lookup into priority order.
 
 
 .vitem &*${srs_encode&~{*&<&'secret'&>&*}{*&<&'return&~path'&>&*}{*&<&'original&~domain'&>&*}}*&
 
 
 .vitem &*${srs_encode&~{*&<&'secret'&>&*}{*&<&'return&~path'&>&*}{*&<&'original&~domain'&>&*}}*&

-SRS encoding.  See SECT &<<SECTSRS>>& for details.
+SRS encoding.  See section &<<SECTSRS>>& for details.

 
 
 
 
 
 


@@ -11122,7 +11172,6 @@ abbreviation &%h%& can be used when &%hash%& is used as an operator.
 
 
 
 
 
 

-.new

 .vitem &*${headerwrap_*&<&'cols'&>&*_*&<&'limit'&>&*:*&<&'string'&>&*}*&
 .cindex header "wrapping operator"
 .cindex expansion "header wrapping"
 .vitem &*${headerwrap_*&<&'cols'&>&*_*&<&'limit'&>&*:*&<&'string'&>&*}*&
 .cindex header "wrapping operator"
 .cindex expansion "header wrapping"


@@ -11136,7 +11185,6 @@ column number is reached.
 Whitespace at a chosen wrap point is removed.
 A line-wrap consists of a newline followed by a tab,
 and the tab is counted as 8 columns.
 Whitespace at a chosen wrap point is removed.
 A line-wrap consists of a newline followed by a tab,
 and the tab is counted as 8 columns.

-.wen

 
 
 
 
 
 


@@ -11573,6 +11621,17 @@ literal question mark).
 .cindex "&%utf8_localpart_from_alabel%& expansion item"
 These convert EAI mail name components between UTF-8 and a-label forms.
 For information on internationalisation support see &<<SECTi18nMTA>>&.
 .cindex "&%utf8_localpart_from_alabel%& expansion item"
 These convert EAI mail name components between UTF-8 and a-label forms.
 For information on internationalisation support see &<<SECTi18nMTA>>&.

+
+
+.vitem &*${xtextd:*&<&'string'&>&*}*&
+.cindex "text forcing in strings"
+.cindex "string" "xtext decoding"
+.cindex "xtext"
+.cindex "&%xtextd%& expansion item"
+This performs xtext decoding of the string (per RFC 3461 section 4).
+
+
+

 .endlist
 
 
 .endlist
 
 


@@ -12062,7 +12121,8 @@ where the first item in the list is the empty string.
 .next
 The item @[] matches any of the local host's interface addresses.
 .next
 .next
 The item @[] matches any of the local host's interface addresses.
 .next

-Single-key lookups are assumed to be like &"net-"& style lookups in host lists,
+Single-key lookups are assumed to be like &"net-"& style lookups in host lists
+(see section &<<SECThoslispatsikey>>&),

 even if &`net-`& is not specified. There is never any attempt to turn the IP
 address into a host name. The most common type of linear search for
 &*match_ip*& is likely to be &*iplsearch*&, in which the file can contain CIDR
 even if &`net-`& is not specified. There is never any attempt to turn the IP
 address into a host name. The most common type of linear search for
 &*match_ip*& is likely to be &*iplsearch*&, in which the file can contain CIDR


@@ -12574,6 +12634,11 @@ contain the trailing slash. If &$config_file$& does not contain a slash,
 .vindex "&$config_file$&"
 The name of the main configuration file Exim is using.
 
 .vindex "&$config_file$&"
 The name of the main configuration file Exim is using.
 

+.vitem &$connection_id$&
+.vindex "&$connection_id$&"
+.cindex connection "identifier logging"
+An identifier for the accepted connection, for use in custom logging.
+

 .vitem &$dkim_verify_status$&
 Results of DKIM verification.
 For details see section &<<SECDKIMVFY>>&.
 .vitem &$dkim_verify_status$&
 Results of DKIM verification.
 For details see section &<<SECDKIMVFY>>&.


@@ -13436,7 +13501,6 @@ The main use of this variable is expected to be to distinguish between
 rejections of MAIL and rejections of RCPT.
 
 .tvar &$recipients$&
 rejections of MAIL and rejections of RCPT.
 
 .tvar &$recipients$&

-.new

 .tvar &$recipients_list$&
 These variables both contain the envelope recipients for a message.
 
 .tvar &$recipients_list$&
 These variables both contain the envelope recipients for a message.
 


@@ -13445,7 +13509,6 @@ The first uses a comma and a space separate the addresses in the replacement tex
 this variable is not intended for further processing.
 
 The second is a proper Exim list; colon-separated.
 this variable is not intended for further processing.
 
 The second is a proper Exim list; colon-separated.

-.wen

 
 However, the variables
 are not generally available, to prevent exposure of Bcc recipients in
 
 However, the variables
 are not generally available, to prevent exposure of Bcc recipients in


@@ -14825,6 +14888,7 @@ listed in more than one group.
 .row &%acl_smtp_rcpt%&               "ACL for RCPT"
 .row &%acl_smtp_starttls%&           "ACL for STARTTLS"
 .row &%acl_smtp_vrfy%&               "ACL for VRFY"
 .row &%acl_smtp_rcpt%&               "ACL for RCPT"
 .row &%acl_smtp_starttls%&           "ACL for STARTTLS"
 .row &%acl_smtp_vrfy%&               "ACL for VRFY"

+.row &%acl_smtp_wellknown%&          "ACL for WELLKNOWN"

 .row &%av_scanner%&                  "specify virus scanner"
 .row &%check_rfc2047_length%&        "check length of RFC 2047 &""encoded &&&
                                       words""&"
 .row &%av_scanner%&                  "specify virus scanner"
 .row &%check_rfc2047_length%&        "check length of RFC 2047 &""encoded &&&
                                       words""&"


@@ -14985,11 +15049,13 @@ See also the &'Policy controls'& section above.
 .row &%dsn_advertise_hosts%&         "advertise DSN extensions to these hosts"
 .row &%ignore_fromline_hosts%&       "allow &""From ""& from these hosts"
 .row &%ignore_fromline_local%&       "allow &""From ""& from local SMTP"
 .row &%dsn_advertise_hosts%&         "advertise DSN extensions to these hosts"
 .row &%ignore_fromline_hosts%&       "allow &""From ""& from these hosts"
 .row &%ignore_fromline_local%&       "allow &""From ""& from local SMTP"

+.row &%limits_advertise_hosts%&      "advertise LIMITS to these hosts"

 .row &%pipelining_advertise_hosts%&  "advertise pipelining to these hosts"
 .row &%pipelining_connect_advertise_hosts%& "advertise pipelining to these hosts"
 .row &%prdr_enable%&                 "advertise PRDR to all hosts"
 .row &%smtputf8_advertise_hosts%&    "advertise SMTPUTF8 to these hosts"
 .row &%tls_advertise_hosts%&         "advertise TLS to these hosts"
 .row &%pipelining_advertise_hosts%&  "advertise pipelining to these hosts"
 .row &%pipelining_connect_advertise_hosts%& "advertise pipelining to these hosts"
 .row &%prdr_enable%&                 "advertise PRDR to all hosts"
 .row &%smtputf8_advertise_hosts%&    "advertise SMTPUTF8 to these hosts"
 .row &%tls_advertise_hosts%&         "advertise TLS to these hosts"

+.row &%wellknown_advertise_hosts%&   "advertise WELLKNOWN to these hosts"

 .endtable
 
 
 .endtable
 
 


@@ -15113,7 +15179,7 @@ log_selector = +8bitmime
 .cindex "&ACL;" "for non-SMTP messages"
 .cindex "non-SMTP messages" "ACLs for"
 This option defines the ACL that is run when a non-SMTP message has been
 .cindex "&ACL;" "for non-SMTP messages"
 .cindex "non-SMTP messages" "ACLs for"
 This option defines the ACL that is run when a non-SMTP message has been

-read and is on the point of being accepted. See chapter &<<CHAPACL>>& for
+read and is on the point of being accepted. See section &<<SECnonSMTP>>& for

 further details.
 
 .option acl_not_smtp_mime main string&!! unset
 further details.
 
 .option acl_not_smtp_mime main string&!! unset


@@ -15125,24 +15191,26 @@ SMTP messages.
 .cindex "&ACL;" "at start of non-SMTP message"
 .cindex "non-SMTP messages" "ACLs for"
 This option defines the ACL that is run before Exim starts reading a
 .cindex "&ACL;" "at start of non-SMTP message"
 .cindex "non-SMTP messages" "ACLs for"
 This option defines the ACL that is run before Exim starts reading a

-non-SMTP message. See chapter &<<CHAPACL>>& for further details.
+non-SMTP message. See section &<<SECnonSMTP>>& for further details.

 
 .option acl_smtp_auth main string&!! unset
 .cindex "&ACL;" "setting up for SMTP commands"
 .cindex "AUTH" "ACL for"
 This option defines the ACL that is run when an SMTP AUTH command is
 
 .option acl_smtp_auth main string&!! unset
 .cindex "&ACL;" "setting up for SMTP commands"
 .cindex "AUTH" "ACL for"
 This option defines the ACL that is run when an SMTP AUTH command is

-received. See chapter &<<CHAPACL>>& for further details.
+received.
+See chapter &<<CHAPACL>>& for general information on ACLs, and chapter
+&<<CHAPSMTPAUTH>>& for details of authentication.

 
 .option acl_smtp_connect main string&!! unset
 .cindex "&ACL;" "on SMTP connection"
 This option defines the ACL that is run when an SMTP connection is received.
 
 .option acl_smtp_connect main string&!! unset
 .cindex "&ACL;" "on SMTP connection"
 This option defines the ACL that is run when an SMTP connection is received.

-See chapter &<<CHAPACL>>& for further details.
+See section &<<SECconnectACL>>& for further details.

 
 .option acl_smtp_data main string&!! unset
 .cindex "DATA" "ACL for"
 This option defines the ACL that is run after an SMTP DATA command has been
 processed and the message itself has been received, but before the final
 
 .option acl_smtp_data main string&!! unset
 .cindex "DATA" "ACL for"
 This option defines the ACL that is run after an SMTP DATA command has been
 processed and the message itself has been received, but before the final

-acknowledgment is sent. See chapter &<<CHAPACL>>& for further details.
+acknowledgment is sent. See section &<<SECdataACLS>>& for further details.

 
 .option acl_smtp_data_prdr main string&!! accept
 .cindex "PRDR" "ACL for"
 
 .option acl_smtp_data_prdr main string&!! accept
 .cindex "PRDR" "ACL for"


@@ -15153,7 +15221,7 @@ This option defines the ACL that,
 if the PRDR feature has been negotiated,
 is run for each recipient after an SMTP DATA command has been
 processed and the message itself has been received, but before the
 if the PRDR feature has been negotiated,
 is run for each recipient after an SMTP DATA command has been
 processed and the message itself has been received, but before the

-acknowledgment is sent. See chapter &<<CHAPACL>>& for further details.
+acknowledgment is sent. See section &<<SECTPRDRACL>>& for further details.

 
 .option acl_smtp_dkim main string&!! unset
 .cindex DKIM "ACL for"
 
 .option acl_smtp_dkim main string&!! unset
 .cindex DKIM "ACL for"


@@ -15164,8 +15232,11 @@ See section &<<SECDKIMVFY>>& for further details.
 
 .option acl_smtp_etrn main string&!! unset
 .cindex "ETRN" "ACL for"
 
 .option acl_smtp_etrn main string&!! unset
 .cindex "ETRN" "ACL for"

+.cindex "ETRN" advertisement

 This option defines the ACL that is run when an SMTP ETRN command is
 This option defines the ACL that is run when an SMTP ETRN command is

-received. See chapter &<<CHAPACL>>& for further details.
+received.
+If no value is set then the ETRN facility is not advertised.
+See chapter &<<CHAPACL>>& for further details.

 
 .option acl_smtp_expn main string&!! unset
 .cindex "EXPN" "ACL for"
 
 .option acl_smtp_expn main string&!! unset
 .cindex "EXPN" "ACL for"


@@ -15176,7 +15247,7 @@ received. See chapter &<<CHAPACL>>& for further details.
 .cindex "EHLO" "ACL for"
 .cindex "HELO" "ACL for"
 This option defines the ACL that is run when an SMTP EHLO or HELO
 .cindex "EHLO" "ACL for"
 .cindex "HELO" "ACL for"
 This option defines the ACL that is run when an SMTP EHLO or HELO

-command is received. See chapter &<<CHAPACL>>& for further details.
+command is received. See section &<<SECheloACL>>& for further details.

 
 
 .option acl_smtp_mail main string&!! unset
 
 
 .option acl_smtp_mail main string&!! unset


@@ -15187,7 +15258,8 @@ received. See chapter &<<CHAPACL>>& for further details.
 .option acl_smtp_mailauth main string&!! unset
 .cindex "AUTH" "on MAIL command"
 This option defines the ACL that is run when there is an AUTH parameter on
 .option acl_smtp_mailauth main string&!! unset
 .cindex "AUTH" "on MAIL command"
 This option defines the ACL that is run when there is an AUTH parameter on

-a MAIL command. See chapter &<<CHAPACL>>& for details of ACLs, and chapter
+a MAIL command.
+See chapter &<<CHAPACL>>& for general information on ACLs, and chapter

 &<<CHAPSMTPAUTH>>& for details of authentication.
 
 .option acl_smtp_mime main string&!! unset
 &<<CHAPSMTPAUTH>>& for details of authentication.
 
 .option acl_smtp_mime main string&!! unset


@@ -15200,7 +15272,7 @@ section &<<SECTscanmimepart>>& for details.
 .cindex "not-QUIT, ACL for"
 This option defines the ACL that is run when an SMTP session
 ends without a QUIT command being received.
 .cindex "not-QUIT, ACL for"
 This option defines the ACL that is run when an SMTP session
 ends without a QUIT command being received.

-See chapter &<<CHAPACL>>& for further details.
+See section &<<SECTNOTQUITACL>>& for further details.

 
 .option acl_smtp_predata main string&!! unset
 This option defines the ACL that is run when an SMTP DATA command is
 
 .option acl_smtp_predata main string&!! unset
 This option defines the ACL that is run when an SMTP DATA command is


@@ -15215,7 +15287,7 @@ received. See chapter &<<CHAPACL>>& for further details.
 .option acl_smtp_rcpt main string&!! unset
 .cindex "RCPT" "ACL for"
 This option defines the ACL that is run when an SMTP RCPT command is
 .option acl_smtp_rcpt main string&!! unset
 .cindex "RCPT" "ACL for"
 This option defines the ACL that is run when an SMTP RCPT command is

-received. See chapter &<<CHAPACL>>& for further details.
+received. See section &<<SECTQUITACL>>& for further details.

 
 .option acl_smtp_starttls main string&!! unset
 .cindex "STARTTLS, ACL for"
 
 .option acl_smtp_starttls main string&!! unset
 .cindex "STARTTLS, ACL for"


@@ -15227,6 +15299,11 @@ received. See chapter &<<CHAPACL>>& for further details.
 This option defines the ACL that is run when an SMTP VRFY command is
 received. See chapter &<<CHAPACL>>& for further details.
 
 This option defines the ACL that is run when an SMTP VRFY command is
 received. See chapter &<<CHAPACL>>& for further details.
 

+.option acl_smtp_wellknown main string&!! unset
+.cindex "WELLKNOWN, ACL for"
+This option defines the ACL that is run when an SMTP WELLKNOWN command is
+received. See section &<<SECTWELLKNOWNACL>>& for further details.
+

 .option add_environment main "string list" empty
 .cindex "environment" "set values"
 This option adds individual environment variables that the
 .option add_environment main "string list" empty
 .cindex "environment" "set values"
 This option adds individual environment variables that the


@@ -15732,9 +15809,9 @@ the ACL once for each signature in the message.
 See section &<<SECDKIMVFY>>&.
 
 
 See section &<<SECDKIMVFY>>&.
 
 

-.option dmarc_forensic_sender main string&!! unset
-.option dmarc_history_file main string unset
-.option dmarc_tld_file main string unset
+.options dmarc_forensic_sender main string&!! unset &&&
+         dmarc_history_file main string unset &&&
+         dmarc_tld_file main string unset

 .cindex DMARC "main section options"
 These options control DMARC processing.
 See section &<<SECDMARC>>& for details.
 .cindex DMARC "main section options"
 These options control DMARC processing.
 See section &<<SECDMARC>>& for details.


@@ -15754,10 +15831,8 @@ by a setting such as this:
 dns_again_means_nonexist = *.in-addr.arpa
 .endd
 This option applies to all DNS lookups that Exim does,
 dns_again_means_nonexist = *.in-addr.arpa
 .endd
 This option applies to all DNS lookups that Exim does,

-.new

 except for TLSA lookups (where knowing about such failures
 is security-relevant).
 except for TLSA lookups (where knowing about such failures
 is security-relevant).

-.wen

 It also applies when the
 &[gethostbyname()]& or &[getipnodebyname()]& functions give temporary errors,
 since these are most likely to be caused by DNS lookup problems. The
 It also applies when the
 &[gethostbyname()]& or &[getipnodebyname()]& functions give temporary errors,
 since these are most likely to be caused by DNS lookup problems. The


@@ -16062,9 +16137,11 @@ routing, but which are not used for listening by the daemon. See section
 
 . 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.

+. WAS:
+. .option "extract_addresses_remove_ &~&~arguments"
+. but apparently this results in searchability problems; bug 1197

 
 

-.option "extract_addresses_remove_arguments" main boolean true &&&
-         extract_addresses_remove_arguments
+.option extract_addresses_remove_arguments main boolean true

 .oindex "&%-t%&"
 .cindex "command line" "addresses with &%-t%&"
 .cindex "Sendmail compatibility" "&%-t%& option"
 .oindex "&%-t%&"
 .cindex "command line" "addresses with &%-t%&"
 .cindex "Sendmail compatibility" "&%-t%& option"


@@ -16203,11 +16280,13 @@ set.
 .cindex "EHLO" "underscores in"
 .cindex "underscore in EHLO/HELO"
 This option can be set to a string of rogue characters that are permitted in
 .cindex "EHLO" "underscores in"
 .cindex "underscore in EHLO/HELO"
 This option can be set to a string of rogue characters that are permitted in

-all EHLO and HELO names in addition to the standard letters, digits,
-hyphens, and dots. If you really must allow underscores, you can set
+non-ip-literal EHLO and HELO names in addition to the standard letters, digits,
+hyphens, and dots. For example if you really must allow underscores,
+you can set

 .code
 helo_allow_chars = _
 .endd
 .code
 helo_allow_chars = _
 .endd

+This option does not apply to names that look like ip-literals.

 Note that the value is one string, not a list.
 
 
 Note that the value is one string, not a list.
 
 


@@ -16337,10 +16416,8 @@ This option is obsolete, and retained only for backward compatibility, because
 nowadays the ACL specified by &%acl_smtp_connect%& can also reject incoming
 connections immediately.
 
 nowadays the ACL specified by &%acl_smtp_connect%& can also reject incoming
 connections immediately.
 

-.new

 If the connection is on a TLS-on-connect port then the TCP connection is
 just dropped.  Otherwise, an SMTP error is sent first.
 If the connection is on a TLS-on-connect port then the TCP connection is
 just dropped.  Otherwise, an SMTP error is sent first.

-.wen

 
 The ability to give an immediate rejection (either by this option or using an
 ACL) is provided for use in unusual cases. Many hosts will just try again,
 
 The ability to give an immediate rejection (either by this option or using an
 ACL) is provided for use in unusual cases. Many hosts will just try again,


@@ -16361,10 +16438,8 @@ local processes, you must create a host list with an empty item. For example:
 .code
 hosts_connection_nolog = :
 .endd
 .code
 hosts_connection_nolog = :
 .endd

-.new

 The hosts affected by this option also do not log "no MAIL in SMTP connection"
 lines, as may commonly be produced by a monitoring system.
 The hosts affected by this option also do not log "no MAIL in SMTP connection"
 lines, as may commonly be produced by a monitoring system.

-.wen

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


@@ -16575,6 +16650,16 @@ has been built with LDAP support.
 
 
 
 
 
 

+.option limits_advertise_hosts main "host list&!!" *
+.cindex LIMITS "suppressing advertising"
+.cindex "ESMTP extensions" LIMITS
+This option can be used to suppress the advertisement of the SMTP
+LIMITS extension (RFC 9422) to specific hosts.
+If permitted, Exim as a server will advertise in the EHLO response
+the limit for RCPT commands set by the &%recipients_max%& option (if it is set)
+and the limit for MAIL commands set by the &%smtp_accept_max_per_connection%&
+option.
+

 .option local_from_check main boolean true
 .cindex "&'Sender:'& header line" "disabling addition of"
 .cindex "&'From:'& header line" "disabling checking of"
 .option local_from_check main boolean true
 .cindex "&'Sender:'& header line" "disabling addition of"
 .cindex "&'From:'& header line" "disabling checking of"


@@ -16672,15 +16757,21 @@ See also the ACL modifier &`control = suppress_local_fixups`&. Section
 .option localhost_number main string&!! unset
 .cindex "host" "locally unique number for"
 .cindex "message ids" "with multiple hosts"
 .option localhost_number main string&!! unset
 .cindex "host" "locally unique number for"
 .cindex "message ids" "with multiple hosts"

+.cindex multiple "systems sharing a spool"
+.cindex "multiple hosts" "sharing a spool"
+.cindex "shared spool directory"
+.cindex "spool directory" sharing

 .vindex "&$localhost_number$&"
 Exim's message ids are normally unique only within the local host. If
 .vindex "&$localhost_number$&"
 Exim's message ids are normally unique only within the local host. If

-uniqueness among a set of hosts is required, each host must set a different
+uniqueness among a set of hosts is required
+(eg. because they share a spool directory),
+each host must set a different

 value for the &%localhost_number%& option. The string is expanded immediately
 after reading the configuration file (so that a number can be computed from the
 host name, for example) and the result of the expansion must be a number in the
 range 0&--16 (or 0&--10 on operating systems with case-insensitive file
 systems). This is available in subsequent string expansions via the variable
 value for the &%localhost_number%& option. The string is expanded immediately
 after reading the configuration file (so that a number can be computed from the
 host name, for example) and the result of the expansion must be a number in the
 range 0&--16 (or 0&--10 on operating systems with case-insensitive file
 systems). This is available in subsequent string expansions via the variable

-&$localhost_number$&. When &%localhost_number is set%&, the final two
+&$localhost_number$&. When &%localhost_number%& is set, the final four

 characters of the message id, instead of just being a fractional part of the
 time, are computed from the time and the local host number as described in
 section &<<SECTmessiden>>&.
 characters of the message id, instead of just being a fractional part of the
 time, are computed from the time and the local host number as described in
 section &<<SECTmessiden>>&.


@@ -17036,7 +17127,6 @@ to be used in conjunction with &(oracle)& lookups (see section &<<SECID72>>&).
 The option is available only if Exim has been built with Oracle support.
 
 
 The option is available only if Exim has been built with Oracle support.
 
 

-.new

 .option panic_coredump main boolean false
 This option is rarely needed but can help for some debugging investigations.
 If set, when an internal error is detected by Exim which is sufficient
 .option panic_coredump main boolean false
 This option is rarely needed but can help for some debugging investigations.
 If set, when an internal error is detected by Exim which is sufficient


@@ -17047,7 +17137,6 @@ then a coredump is requested.
 Note that most systems require additional administrative configuration
 to permit write a core file for a setuid program, which is Exim's
 common installed configuration.
 Note that most systems require additional administrative configuration
 to permit write a core file for a setuid program, which is Exim's
 common installed configuration.

-.wen

 
 .option percent_hack_domains main "domain list&!!" unset
 .cindex "&""percent hack""&"
 
 .option percent_hack_domains main "domain list&!!" unset
 .cindex "&""percent hack""&"


@@ -17130,7 +17219,7 @@ See also the &%hosts_pipe_connect%& smtp transport option.
 
 The SMTP service extension keyword advertised is &"PIPECONNECT"&;
 it permits the client to pipeline
 
 The SMTP service extension keyword advertised is &"PIPECONNECT"&;
 it permits the client to pipeline

-TCP connection and hello command (inclear phase),
+TCP connection and hello command (cleatext phase),

 or TLS-establishment and hello command (encrypted phase),
 on later connections to the same host.
 
 or TLS-establishment and hello command (encrypted phase),
 on later connections to the same host.
 


@@ -17474,16 +17563,24 @@ or if the message was submitted locally (not using TCP/IP), and the &%-bnq%&
 option was not set.
 
 
 option was not set.
 
 

-.option recipients_max main integer 50000
+.option recipients_max main integer&!! 50000

 .cindex "limit" "number of recipients"
 .cindex "recipient" "maximum number"
 .cindex "limit" "number of recipients"
 .cindex "recipient" "maximum number"

-If this option is set greater than zero, it specifies the maximum number of
+If the value resulting from expanding this option
+is set greater than zero, it specifies the maximum number of

 original recipients for any message. Additional recipients that are generated
 by aliasing or forwarding do not count. SMTP messages get a 452 response for
 all recipients over the limit; earlier recipients are delivered as normal.
 Non-SMTP messages with too many recipients are failed, and no deliveries are
 done.
 
 original recipients for any message. Additional recipients that are generated
 by aliasing or forwarding do not count. SMTP messages get a 452 response for
 all recipients over the limit; earlier recipients are delivered as normal.
 Non-SMTP messages with too many recipients are failed, and no deliveries are
 done.
 

+For SMTP message the expansion is done after the connection is
+accepted (but before any SMTP conversation) and may depend on
+the IP addresses and port numbers of the connection.
+&*Note*&: If an expansion is used for the option,
+care should be taken that a resonable value results for
+non-SMTP messages.
+

 .cindex "RCPT" "maximum number of incoming"
 &*Note*&: The RFCs specify that an SMTP server should accept at least 100
 RCPT commands in a single message.
 .cindex "RCPT" "maximum number of incoming"
 &*Note*&: The RFCs specify that an SMTP server should accept at least 100
 RCPT commands in a single message.


@@ -17690,8 +17787,7 @@ live with.
 . searchable.  NM changed this occurrence for bug 1197 to no longer allow
 . the option name to split.
 
 . 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

 .cindex "SMTP" "limiting incoming message count"
 .cindex "limit" "messages per SMTP connection"
 The value of this option limits the number of MAIL commands that Exim is
 .cindex "SMTP" "limiting incoming message count"
 .cindex "limit" "messages per SMTP connection"
 The value of this option limits the number of MAIL commands that Exim is


@@ -17745,8 +17841,7 @@ various &%-od%&&'x'& command line options.
 
 . See the comment on smtp_accept_max_per_connection
 
 
 . See the comment on smtp_accept_max_per_connection
 

-.option "smtp_accept_queue_per_connection" main integer 10 &&&
-         smtp_accept_queue_per_connection
+.option smtp_accept_queue_per_connection main integer 10

 .cindex "queueing incoming messages"
 .cindex "message" "queueing by message count"
 This option limits the number of delivery processes that Exim starts
 .cindex "queueing incoming messages"
 .cindex "message" "queueing by message count"
 This option limits the number of delivery processes that Exim starts


@@ -17830,10 +17925,8 @@ positive response to an SMTP connection. The default setting is:
 smtp_banner = $smtp_active_hostname ESMTP Exim \
   $version_number $tod_full
 .endd
 smtp_banner = $smtp_active_hostname ESMTP Exim \
   $version_number $tod_full
 .endd

-.new

 Failure to expand the string causes a panic error;
 a forced fail just closes the connection.
 Failure to expand the string causes a panic error;
 a forced fail just closes the connection.

-.wen

 If you want to create a
 multiline response to the initial SMTP connection, use &"\n"& in the string at
 appropriate points, but not at the end. Note that the 220 code is not included
 If you want to create a
 multiline response to the initial SMTP connection, use &"\n"& in the string at
 appropriate points, but not at the end. Note that the 220 code is not included


@@ -18579,9 +18672,7 @@ It has no effect when Exim is used with GnuTLS
 &%tls_require_ciphers%& option).
 
 After expansion it must contain
 &%tls_require_ciphers%& option).
 
 After expansion it must contain

-.new

 one or (only for OpenSSL versiona 1.1.1 onwards) more
 one or (only for OpenSSL versiona 1.1.1 onwards) more

-.wen

 EC curve names, such as &`prime256v1`&, &`secp384r1`&, or &`P-521`&.
 Consult your OpenSSL manual for valid curve names.
 
 EC curve names, such as &`prime256v1`&, &`secp384r1`&, or &`P-521`&.
 Consult your OpenSSL manual for valid curve names.
 


@@ -18589,9 +18680,7 @@ For OpenSSL versions before (and not including) 1.0.2, the string
 &`auto`& selects &`prime256v1`&. For more recent OpenSSL versions
 &`auto`& tells the library to choose.
 
 &`auto`& selects &`prime256v1`&. For more recent OpenSSL versions
 &`auto`& tells the library to choose.
 

-.new

 If the option expands to an empty string, the effect is undefined.
 If the option expands to an empty string, the effect is undefined.

-.wen

 
 
 .option tls_ocsp_file main string&!! unset
 
 
 .option tls_ocsp_file main string&!! unset


@@ -18882,6 +18971,12 @@ absolute and untainted.
 See also &%bounce_message_file%&.
 
 
 See also &%bounce_message_file%&.
 
 

+.option wellknown_advertise_hosts main boolean unset
+.cindex WELLKNOWN advertisement
+.cindex "ESMTP extensions" WELLKNOWN
+This option enables the advertising of the SMTP WELLKNOWN extension.
+See also the &%acl_smtp_wellknown%& ACL (&<<SECTWELLKNOWNACL>>&).
+

 .option write_rejectlog main boolean true
 .cindex "reject log" "disabling"
 If this option is set false, Exim no longer writes anything to the reject log.
 .option write_rejectlog main boolean true
 .cindex "reject log" "disabling"
 If this option is set false, Exim no longer writes anything to the reject log.


@@ -22156,6 +22251,12 @@ subject to address rewriting. Otherwise, they are treated like new addresses
 and are rewritten according to the global rewriting rules.
 
 
 and are rewritten according to the global rewriting rules.
 
 

+.option sieve_inbox redirect string&!! inbox
+.new
+The value of this option is passed to a Sieve filter to specify the
+name of the mailbox used for "keep" operations (explicit or implicit).
+.wen
+

 .option sieve_subaddress redirect string&!! unset
 The value of this option is passed to a Sieve filter to specify the
 :subaddress part of an address.
 .option sieve_subaddress redirect string&!! unset
 The value of this option is passed to a Sieve filter to specify the
 :subaddress part of an address.


@@ -22832,8 +22933,11 @@ If unset, or expanding to an empty string, no filtering is done.
 When the message is about to be written out, the command specified by
 &%transport_filter%& is started up in a separate, parallel process, and
 the entire message, including the header lines, is passed to it on its standard
 When the message is about to be written out, the command specified by
 &%transport_filter%& is started up in a separate, parallel process, and
 the entire message, including the header lines, is passed to it on its standard

-input (this in fact is done from a third process, to avoid deadlock). The
-command must be specified as an absolute path.
+input (this in fact is done from a third process, to avoid deadlock).
+The command must be specified as an absolute path.
+
+The process run by the command must use its standard input as the message
+data to be transformed, and write the results on its standard output.

 
 The lines of the message that are written to the transport filter are
 terminated by newline (&"\n"&). The message is passed to the filter before any
 
 The lines of the message that are written to the transport filter are
 terminated by newline (&"\n"&). The message is passed to the filter before any


@@ -23189,7 +23293,11 @@ fileinto "folder23";
 .endd
 In this situation, the expansion of &%file%& or &%directory%& in the transport
 must transform the relative path into an appropriate absolute filename. In the
 .endd
 In this situation, the expansion of &%file%& or &%directory%& in the transport
 must transform the relative path into an appropriate absolute filename. In the

-case of Sieve filters, the name &'inbox'& must be handled. It is the name that
+case of Sieve filters, the name &'inbox'& must be handled. It is the
+.new
+default
+.wen
+name that

 is used as a result of a &"keep"& action in the filter. This example shows one
 way of handling this requirement:
 .code
 is used as a result of a &"keep"& action in the filter. This example shows one
 way of handling this requirement:
 .code


@@ -23205,6 +23313,12 @@ With this setting of &%file%&, &'inbox'& refers to the standard mailbox
 location, absolute paths are used without change, and other folders are in the
 &_mail_& directory within the home directory.
 
 location, absolute paths are used without change, and other folders are in the
 &_mail_& directory within the home directory.
 

+.new
+An alternative for the &"keep"& aspect is to use the &%sieve_inbox%& option
+on the redirect router that calls the Sieve filter,
+to explicitly set the filename used.
+.wen
+

 &*Note 1*&: While processing an Exim filter, a relative path such as
 &_folder23_& is turned into an absolute path if a home directory is known to
 the router. In particular, this is the case if &%check_local_user%& is set. If
 &*Note 1*&: While processing an Exim filter, a relative path such as
 &_folder23_& is turned into an absolute path if a home directory is known to
 the router. In particular, this is the case if &%check_local_user%& is set. If


@@ -23215,6 +23329,10 @@ path to the transport.
 &*Note 2*&: An absolute path in &$address_file$& is not treated specially;
 the &%file%& or &%directory%& option is still used if it is set.
 
 &*Note 2*&: An absolute path in &$address_file$& is not treated specially;
 the &%file%& or &%directory%& option is still used if it is set.
 

+.new
+&*Note 3*&: Permitting a user to enable writes to an absolute path
+may be a security issue.
+.wen

 
 
 
 
 
 


@@ -24517,7 +24635,7 @@ when the message is specified by the transport.
 .cindex "transports" "&(lmtp)&"
 .cindex "&(lmtp)& transport"
 .cindex "LMTP" "over a pipe"
 .cindex "transports" "&(lmtp)&"
 .cindex "&(lmtp)& transport"
 .cindex "LMTP" "over a pipe"

-.cindex "LMTP" "over a socket"
+.cindex "LMTP" "over a unix-domain socket"

 The &(lmtp)& transport runs the LMTP protocol (RFC 2033) over a pipe to a
 specified command
 or by interacting with a Unix domain socket.
 The &(lmtp)& transport runs the LMTP protocol (RFC 2033) over a pipe to a
 specified command
 or by interacting with a Unix domain socket.


@@ -24868,7 +24986,7 @@ Exim, and each argument is separately expanded, as described in section
 No part of the resulting command may be tainted.
 
 
 No part of the resulting command may be tainted.
 
 

-.option environment pipe string&!! unset
+.option environment pipe "string list&!!" unset

 .cindex "&(pipe)& transport" "environment for command"
 .cindex "environment" "&(pipe)& transport"
 This option is used to add additional variables to the environment in which the
 .cindex "&(pipe)& transport" "environment for command"
 .cindex "environment" "&(pipe)& transport"
 This option is used to add additional variables to the environment in which the


@@ -25374,6 +25492,11 @@ over a single TCP/IP connection. If the value is zero, there is no limit.
 For testing purposes, this value can be overridden by the &%-oB%& command line
 option.
 
 For testing purposes, this value can be overridden by the &%-oB%& command line
 option.
 

+.cindex "ESMTP extensions" LIMITS
+If the peer advertises a LIMITS extension with a MAILMAX value,
+and either TLSS is in use or was not advertised,
+that value also constrains the result of this option.
+

 
 .option dane_require_tls_ciphers smtp string&!! unset
 .cindex "TLS" "requiring specific ciphers for DANE"
 
 .option dane_require_tls_ciphers smtp string&!! unset
 .cindex "TLS" "requiring specific ciphers for DANE"


@@ -25586,15 +25709,22 @@ load-balancer, matching the session stored in the client's cache.
 
 Exim can pull out a server name, if there is one, from the response to the
 client's SMTP EHLO command.
 
 Exim can pull out a server name, if there is one, from the response to the
 client's SMTP EHLO command.

-The default value of this option:
+For normal STARTTLS use, the default value of this option:

 .code
     ${if and { {match {$host} {.outlook.com\$}} \
                {match {$item} {\N^250-([\w.]+)\s\N}} \
             } {$1}}
 .endd
 suffices for one known case.
 .code
     ${if and { {match {$host} {.outlook.com\$}} \
                {match {$item} {\N^250-([\w.]+)\s\N}} \
             } {$1}}
 .endd
 suffices for one known case.

+

 During the expansion of this option the &$item$& variable will have the
 server's EHLO response.
 During the expansion of this option the &$item$& variable will have the
 server's EHLO response.

+
+For TLS-on-connect connections we do not have an EHLO
+response to use. Because of this the default value of this option is
+set to a static string for those cases, meaning that resumption will
+always be attempted if permitted by the &%tls_resumption_hosts%& option.
+

 The result of the option expansion is included in the key used to store and
 retrieve the TLS session, for session resumption.
 
 The result of the option expansion is included in the key used to store and
 retrieve the TLS session, for session resumption.
 


@@ -25783,11 +25913,9 @@ Exim will request a Certificate Status on a
 TLS session for any host that matches this list.
 &%tls_verify_certificates%& should also be set for the transport.
 
 TLS session for any host that matches this list.
 &%tls_verify_certificates%& should also be set for the transport.
 

-.new

 The default is &"**"& if DANE is not in use for the connection,
 or if DANE-TA us used.
 It is empty if DANE-EE is used.
 The default is &"**"& if DANE is not in use for the connection,
 or if DANE-TA us used.
 It is empty if DANE-EE is used.

-.wen

 
 .option hosts_require_alpn smtp "host list&!!" unset
 .cindex ALPN "require negotiation in client"
 
 .option hosts_require_alpn smtp "host list&!!" unset
 .cindex ALPN "require negotiation in client"


@@ -25933,25 +26061,28 @@ has advertised support for IGNOREQUOTA in its response to the LHLO command.
 .option max_rcpt smtp integer&!! 100
 .cindex "RCPT" "maximum number of outgoing"
 This option,
 .option max_rcpt smtp integer&!! 100
 .cindex "RCPT" "maximum number of outgoing"
 This option,

-.new

 after expansion,
 after expansion,

-.wen

 limits the number of RCPT commands that are sent in a single
 SMTP message transaction.
 A value setting of zero disables the limit.
 
 limits the number of RCPT commands that are sent in a single
 SMTP message transaction.
 A value setting of zero disables the limit.
 

-.new

 If a constant is given,
 If a constant is given,

-.wen

 each set of addresses is treated independently, and
 so can cause parallel connections to the same host if &%remote_max_parallel%&
 permits this.
 
 each set of addresses is treated independently, and
 so can cause parallel connections to the same host if &%remote_max_parallel%&
 permits this.
 

+.cindex "ESMTP extensions" LIMITS
+If the peer advertises a LIMITS extension with a RCPTMAX value,
+and either TLSS is in use or was not advertised,
+that value also constrains the result of this option
+and no parallel connections will be caused on meeting the RCPTMAX limit.
+

 
 .option message_linelength_limit smtp integer 998
 .cindex "line length" limit
 This option sets the maximum line length, in bytes, that the transport
 will send.  Any messages with lines exceeding the given value
 
 .option message_linelength_limit smtp integer 998
 .cindex "line length" limit
 This option sets the maximum line length, in bytes, that the transport
 will send.  Any messages with lines exceeding the given value

+(before a transport filter, if any)

 will fail and a failure-DSN ("bounce") message will if possible be returned
 to the sender.
 The default value is that defined by the SMTP standards.
 will fail and a failure-DSN ("bounce") message will if possible be returned
 to the sender.
 The default value is that defined by the SMTP standards.


@@ -25977,6 +26108,12 @@ If the connection is DANE-enabled then this option is ignored;
 only messages having the domain used for the DANE TLSA lookup are
 sent on the connection.
 
 only messages having the domain used for the DANE TLSA lookup are
 sent on the connection.
 

+.cindex "ESMTP extensions" LIMITS
+If the peer advertises a LIMITS extension with a RCPTDOMAINMAX value,
+and either TLSS is in use or was not advertised,
+this option is regarded as being false.
+
+

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


@@ -26010,6 +26147,9 @@ protocol (RFC 2033) instead of SMTP. This protocol is sometimes used for local
 deliveries into closed message stores. Exim also has support for running LMTP
 over a pipe to a local process &-- see chapter &<<CHAPLMTP>>&.
 
 deliveries into closed message stores. Exim also has support for running LMTP
 over a pipe to a local process &-- see chapter &<<CHAPLMTP>>&.
 

+&*Note*&: When using LMTP it should be considered whether the default values
+for some other features, such as DANE, are appropriate.
+

 If this option is set to &"smtps"&, the default value for the &%port%& option
 changes to &"smtps"&, and the transport initiates TLS immediately after
 connecting, as an outbound SSL-on-connect, instead of using STARTTLS to upgrade.
 If this option is set to &"smtps"&, the default value for the &%port%& option
 changes to &"smtps"&, and the transport initiates TLS immediately after
 connecting, as an outbound SSL-on-connect, instead of using STARTTLS to upgrade.


@@ -27753,7 +27893,6 @@ no successful authentication.
 Successful authentication sets up information used by the
 &%authresults%& expansion item.
 
 Successful authentication sets up information used by the
 &%authresults%& expansion item.
 

-.new

 .cindex authentication "failure event, server"
 If an authenticator is run and does not succeed,
 an event (see &<<CHAPevents>>&) of type "auth:fail" is raised.
 .cindex authentication "failure event, server"
 If an authenticator is run and does not succeed,
 an event (see &<<CHAPevents>>&) of type "auth:fail" is raised.


@@ -27764,7 +27903,6 @@ will be valid.
 If the event is serviced and a string is returned then the string will be logged
 instead of the default log line.
 See <<CHAPevents>> for details on events.
 If the event is serviced and a string is returned then the string will be logged
 instead of the default log line.
 See <<CHAPevents>> for details on events.

-.wen

 
 
 .section "Testing server authentication" "SECID169"
 
 
 .section "Testing server authentication" "SECID169"


@@ -27843,7 +27981,6 @@ Exim abandons trying to send the message to the host for the moment. It will
 try again later. If there are any backup hosts available, they are tried in the
 usual way.
 
 try again later. If there are any backup hosts available, they are tried in the
 usual way.
 

-.new

 .next
 .cindex authentication "failure event, client"
 If the response to authentication is a permanent error (5&'xx'& code),
 .next
 .cindex authentication "failure event, client"
 If the response to authentication is a permanent error (5&'xx'& code),


@@ -27853,7 +27990,6 @@ While the event is being processed the variable
 will be valid.
 If the event is serviced and a string is returned then the string will be logged.
 See <<CHAPevents>> for details on events.
 will be valid.
 If the event is serviced and a string is returned then the string will be logged.
 See <<CHAPevents>> for details on events.

-.wen

 
 .next
 If the response to authentication is a permanent error (5&'xx'& code), Exim
 
 .next
 If the response to authentication is a permanent error (5&'xx'& code), Exim


@@ -28433,11 +28569,9 @@ dovecot_ntlm:
   server_set_id = $auth1
 .endd
 
   server_set_id = $auth1
 .endd
 

-.new

 &*Note*&: plaintext authentication methods such as PLAIN and LOGIN
 should not be advertised on cleartext SMTP connections.
 See the discussion in section &<<SECTplain_TLS>>&.
 &*Note*&: plaintext authentication methods such as PLAIN and LOGIN
 should not be advertised on cleartext SMTP connections.
 See the discussion in section &<<SECTplain_TLS>>&.

-.wen

 
 If the SMTP connection is encrypted, or if &$sender_host_address$& is equal to
 &$received_ip_address$& (that is, the connection is local), the &"secured"&
 
 If the SMTP connection is encrypted, or if &$sender_host_address$& is equal to
 &$received_ip_address$& (that is, the connection is local), the &"secured"&


@@ -29246,7 +29380,8 @@ When using OpenSSL, this option is ignored.
 (If an API is found to let OpenSSL be configured in this way,
 let the Exim Maintainers know and we'll likely use it).
 .next
 (If an API is found to let OpenSSL be configured in this way,
 let the Exim Maintainers know and we'll likely use it).
 .next

-With GnuTLS, if an explicit list is used for the &%tls_privatekey%& main option, it must be ordered to match the &%tls_certificate%& list.
+With GnuTLS, if an explicit list is used for the &%tls_privatekey%& main option,
+it must be ordered to match the &%tls_certificate%& list.

 .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


@@ -30508,12 +30643,17 @@ Section 4.3 of that document.
 .subsection General
 Under GnuTLS, DANE is only supported from version 3.0.0 onwards.
 
 .subsection General
 Under GnuTLS, DANE is only supported from version 3.0.0 onwards.
 

-DANE is specified in published RFCs and decouples certificate authority trust
+DANE is specified in RFC 6698. It decouples certificate authority trust

 selection from a "race to the bottom" of "you must trust everything for mail
 to get through".
 selection from a "race to the bottom" of "you must trust everything for mail
 to get through".

-There is an alternative technology called MTA-STS, which
-instead publishes MX trust anchor information on an HTTPS website.  At the
-time this text was last updated, MTA-STS was still a draft, not yet an RFC.
+It does retain the need to trust the assurances provided by the DNSSEC tree.
+
+There is an alternative technology called MTA-STS (RFC 8461), which
+instead publishes MX trust anchor information on an HTTPS website.
+The discovery of the address for that website does not (per standard)
+require DNSSEC, and could be regarded as being less secure than DANE
+as a result.
+

 Exim has no support for MTA-STS as a client, but Exim mail server operators
 can choose to publish information describing their TLS configuration using
 MTA-STS to let those clients who do use that protocol derive trust
 Exim has no support for MTA-STS as a client, but Exim mail server operators
 can choose to publish information describing their TLS configuration using
 MTA-STS to let those clients who do use that protocol derive trust


@@ -30584,6 +30724,7 @@ options in the main part of the configuration. These options are:
 .cindex "RCPT" "ACL for"
 .cindex "STARTTLS, ACL for"
 .cindex "VRFY" "ACL for"
 .cindex "RCPT" "ACL for"
 .cindex "STARTTLS, ACL for"
 .cindex "VRFY" "ACL for"

+.cindex "WELLKNOWN" "ACL for"

 .cindex "SMTP" "connection, ACL for"
 .cindex "non-SMTP messages" "ACLs for"
 .cindex "MIME content scanning" "ACL for"
 .cindex "SMTP" "connection, ACL for"
 .cindex "non-SMTP messages" "ACLs for"
 .cindex "MIME content scanning" "ACL for"


@@ -30610,6 +30751,7 @@ options in the main part of the configuration. These options are:
 .irow &%acl_smtp_rcpt%&        "ACL for RCPT"
 .irow &%acl_smtp_starttls%&    "ACL for STARTTLS"
 .irow &%acl_smtp_vrfy%&        "ACL for VRFY"
 .irow &%acl_smtp_rcpt%&        "ACL for RCPT"
 .irow &%acl_smtp_starttls%&    "ACL for STARTTLS"
 .irow &%acl_smtp_vrfy%&        "ACL for VRFY"

+.irow &%acl_smtp_wellknown%&   "ACL for WELLKNOWN"

 .endtable
 
 For example, if you set
 .endtable
 
 For example, if you set


@@ -30625,7 +30767,7 @@ trying to deliver the message. It is therefore recommended that you do as much
 testing as possible at RCPT time.
 
 
 testing as possible at RCPT time.
 
 

-.subsection "The non-SMTP ACLs" SECID190
+.subsection "The non-SMTP ACLs" SECnonSMTP

 .cindex "non-SMTP messages" "ACLs for"
 The non-SMTP ACLs apply to all non-interactive incoming messages, that is, they
 apply to batched SMTP as well as to non-SMTP messages. (Batched SMTP is not
 .cindex "non-SMTP messages" "ACLs for"
 The non-SMTP ACLs apply to all non-interactive incoming messages, that is, they
 apply to batched SMTP as well as to non-SMTP messages. (Batched SMTP is not


@@ -30659,7 +30801,7 @@ kind of rejection is treated as permanent, because there is no way of sending a
 temporary error for these kinds of message.
 
 
 temporary error for these kinds of message.
 
 

-.subsection "The SMTP connect ACL" SECID191
+.subsection "The SMTP connect ACL" SECconnectACL

 .cindex "SMTP" "connection, ACL for"
 .oindex &%smtp_banner%&
 The ACL test specified by &%acl_smtp_connect%& happens at the start of an SMTP
 .cindex "SMTP" "connection, ACL for"
 .oindex &%smtp_banner%&
 The ACL test specified by &%acl_smtp_connect%& happens at the start of an SMTP


@@ -30669,14 +30811,12 @@ accepted by an &%accept%& verb that has a &%message%& modifier, the contents of
 the message override the banner message that is otherwise specified by the
 &%smtp_banner%& option.
 
 the message override the banner message that is otherwise specified by the
 &%smtp_banner%& option.
 

-.new

 For tls-on-connect connections, the ACL is run before the TLS connection
 is accepted; if the ACL does not accept then the TCP connection is dropped without
 any TLS startup attempt and without any SMTP response being transmitted.
 For tls-on-connect connections, the ACL is run before the TLS connection
 is accepted; if the ACL does not accept then the TCP connection is dropped without
 any TLS startup attempt and without any SMTP response being transmitted.

-.wen

 
 
 
 

-.subsection "The EHLO/HELO ACL" SECID192
+.subsection "The EHLO/HELO ACL" SECheloACL

 .cindex "EHLO" "ACL for"
 .cindex "HELO" "ACL for"
 The ACL test specified by &%acl_smtp_helo%& happens when the client issues an
 .cindex "EHLO" "ACL for"
 .cindex "HELO" "ACL for"
 The ACL test specified by &%acl_smtp_helo%& happens when the client issues an


@@ -30697,7 +30837,7 @@ affect the EHLO options that are listed on the second and subsequent lines of
 an EHLO response.
 
 
 an EHLO response.
 
 

-.subsection "The DATA ACLs" SECID193
+.subsection "The DATA ACLs" SECdataACLS

 .cindex "DATA" "ACLs for"
 Two ACLs are associated with the DATA command, because it is two-stage
 command, with two responses being sent to the client.
 .cindex "DATA" "ACLs for"
 Two ACLs are associated with the DATA command, because it is two-stage
 command, with two responses being sent to the client.


@@ -30740,6 +30880,10 @@ and the &%acl_smtp_mime%& ACLs.
 The &%acl_smtp_dkim%& ACL is available only when Exim is compiled with DKIM support
 enabled (which is the default).
 
 The &%acl_smtp_dkim%& ACL is available only when Exim is compiled with DKIM support
 enabled (which is the default).
 

+If, for a specific message, an ACL control
+&*dkim_disable_verify*&
+has been set, this &%acl_smtp_dkim%& ACL is not called.
+

 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.
 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.


@@ -30790,6 +30934,60 @@ This ACL is evaluated after &%acl_smtp_dkim%& but before &%acl_smtp_data%&.
 If the ACL is not defined, processing completes as if
 the feature was not requested by the client.
 
 If the ACL is not defined, processing completes as if
 the feature was not requested by the client.
 

+.subsection "The SMTP WELLKNOWN ACL" SECTWELLKNOWNACL
+.cindex "WELLKNOWN" "ACL for"
+.oindex "&%acl_smtp_wellknown%&"
+The &%acl_smtp_wellknown%& ACL is available only when Exim is compiled
+with WELLKNOWN support enabled.
+
+The ACL determines the response to an SMTP WELLKNOWN command, using the normal
+accept/defer/deny verbs for the response code,
+and a new &"control=wellknown"& modifier.
+This modifier takes a single option, separated by a '/'
+character, which must be the name of a file containing the response
+cleartext.  The modifier is expanded before use in the usual way before
+it is used.  The configuration is responsible for picking a suitable file
+to return and, most importantly, not returning any unexpected file.
+The argument for the SMTP verb will be available in the &$smtp_command_argument$&
+variable and can be used for building the file path.
+If the file path given in the modifier is empty or inacessible, the control will
+fail.
+
+For example:
+.code
+ check_wellknown:
+  accept control = wellknown/\
+                   ${lookup {${xtextd:$smtp_command_argument}} \
+                       dsearch,key=path,filter=file,ret=full \
+                       {$spooldir/wellknown.d}}
+.endd
+File content will be encoded in &"xtext"& form, and line-wrapping
+for line-length limitation will be done before transmission.
+A response summary line will be prepended, with the (pre-encoding) file size.
+
+The above example uses the expansion operator ${xtextd:<coded-string>}
+which is needed to decode the xtext-encoded key from the SMTP verb.
+
+Under the util directory there is a "mailtest" utility which can be used
+to test/retrieve WELLKNOWN items. Syntax is
+.code
+  mailtest -h host.example.com -w security.txt
+.endd
+
+WELLKNOWN is a ESMTP extension providing access to extended
+information about the server.  It is modelled on the webserver
+facilities documented in RFC 8615 and can be used for a security.txt
+file and could be used for ACME handshaking (RFC 8555).
+
+Exim will advertise WELLKNOWN support in the EHLO response
+.oindex &%wellknown_advertise_hosts%&
+(conditional on a new option &%wellknown_advertise_hosts%&)
+and service WELLKNOWN smtp verbs having a single parameter
+giving a key for an item of "site-wide metadata".
+The verb and key are separated by whitespace,
+and the key is xtext-encoded (per RFC 3461 section 4).
+
+

 .subsection "The QUIT ACL" SECTQUITACL
 .cindex "QUIT, ACL for"
 The ACL for the SMTP QUIT command is anomalous, in that the outcome of the ACL
 .subsection "The QUIT ACL" SECTQUITACL
 .cindex "QUIT, ACL for"
 The ACL for the SMTP QUIT command is anomalous, in that the outcome of the ACL


@@ -30960,12 +31158,13 @@ For &%acl_not_smtp%&, &%acl_smtp_auth%&, &%acl_smtp_connect%&,
 &%acl_smtp_mime%&, &%acl_smtp_predata%&, and &%acl_smtp_starttls%&, the action
 when the ACL is not defined is &"accept"&.
 
 &%acl_smtp_mime%&, &%acl_smtp_predata%&, and &%acl_smtp_starttls%&, the action
 when the ACL is not defined is &"accept"&.
 

-For the others (&%acl_smtp_etrn%&, &%acl_smtp_expn%&, &%acl_smtp_rcpt%&, and
-&%acl_smtp_vrfy%&), the action when the ACL is not defined is &"deny"&.
-This means that &%acl_smtp_rcpt%& must be defined in order to receive any
-messages over an SMTP connection. For an example, see the ACL in the default
-configuration file.
-
+For the others (&%acl_smtp_etrn%&, &%acl_smtp_expn%&, &%acl_smtp_rcpt%&,
+&%acl_smtp_vrfy%&
+and &%acl_smtp_wellknown%&),
+the action when the ACL
+is not defined is &"deny"&.  This means that &%acl_smtp_rcpt%& must be
+defined in order to receive any messages over an SMTP connection.
+For an example, see the ACL in the default configuration file.

 
 
 
 
 
 


@@ -31037,7 +31236,8 @@ option to do this.)
 .section "Format of an ACL" "SECID199"
 .cindex "&ACL;" "format of"
 .cindex "&ACL;" "verbs, definition of"
 .section "Format of an ACL" "SECID199"
 .cindex "&ACL;" "format of"
 .cindex "&ACL;" "verbs, definition of"

-An individual ACL consists of a number of statements. Each statement starts
+An individual ACL definition consists of a number of statements.
+Each statement starts

 with a verb, optionally followed by a number of conditions and &"modifiers"&.
 Modifiers can change the way the verb operates, define error and log messages,
 set variables, insert delays, and vary the processing of accepted messages.
 with a verb, optionally followed by a number of conditions and &"modifiers"&.
 Modifiers can change the way the verb operates, define error and log messages,
 set variables, insert delays, and vary the processing of accepted messages.


@@ -31056,6 +31256,9 @@ happens then depends on the verb (and in one case, on a special modifier). Not
 all the conditions make sense at every testing point. For example, you cannot
 test a sender address in the ACL that is run for a VRFY command.
 
 all the conditions make sense at every testing point. For example, you cannot
 test a sender address in the ACL that is run for a VRFY command.
 

+The definition of an ACL ends where another starts,
+or a different configuration section starts.
+

 
 .section "ACL verbs" "SECID200"
 The ACL verbs are as follows:
 
 .section "ACL verbs" "SECID200"
 The ACL verbs are as follows:


@@ -31852,12 +32055,17 @@ This control turns off DKIM verification processing entirely.  For details on
 the operation and configuration of DKIM, see section &<<SECDKIM>>&.
 
 
 the operation and configuration of DKIM, see section &<<SECDKIM>>&.
 
 

-.vitem &*control&~=&~dmarc_disable_verify*&
+.vitem &*control&~=&~dmarc_disable_verify*& &&&
+       &*control&~=&~dmarc_enable_forensic*&

 .cindex "disable DMARC verify"
 .cindex "disable DMARC verify"

-.cindex "DMARC" "disable verify"
-This control turns off DMARC verification processing entirely.  For details on
+.cindex DMARC "disable verify"
+.cindex DMARC controls
+.cindex DMARC "forensic mails"
+These control affect DMARC processing.  For details on

 the operation and configuration of DMARC, see section &<<SECDMARC>>&.
 
 the operation and configuration of DMARC, see section &<<SECDMARC>>&.
 

+The &"disable"& turns off DMARC verification processing entirely.
+

 
 .vitem &*control&~=&~dscp/*&<&'value'&>
 .cindex "&ACL;" "setting DSCP value"
 
 .vitem &*control&~=&~dscp/*&<&'value'&>
 .cindex "&ACL;" "setting DSCP value"


@@ -32066,6 +32274,11 @@ that are being submitted at the same time using &%-bs%& or &%-bS%&.
 This control enables conversion of UTF-8 in message envelope addresses
 to a-label form.
 For details see section &<<SECTi18nMTA>>&.
 This control enables conversion of UTF-8 in message envelope addresses
 to a-label form.
 For details see section &<<SECTi18nMTA>>&.

+
+.vitem &*control&~=&~wellknown*&
+This control sets up a response data file for a WELLKNOWN SMTP command.
+It may only be used in an ACL servicing that command.
+For details see section &<<SECTWELLKNOWNACL>>&.

 .endlist vlist
 
 
 .endlist vlist
 
 


@@ -32210,7 +32423,6 @@ DATA, MIME or DKIM ACLs for a message delivered by cutthrough routing.
 
 More than one header can be removed at the same time by using a colon separated
 list of header specifiers.
 
 More than one header can be removed at the same time by using a colon separated
 list of header specifiers.

-.new

 If a specifier does not start with a circumflex (^)
 then it is treated as a header name.
 The header name matching is case insensitive.
 If a specifier does not start with a circumflex (^)
 then it is treated as a header name.
 The header name matching is case insensitive.


@@ -32224,7 +32436,6 @@ Example:
 .code
 remove_header = \N^(?i)Authentication-Results\s*::\s*example.org;\N
 .endd
 .code
 remove_header = \N^(?i)Authentication-Results\s*::\s*example.org;\N
 .endd

-.wen

 
 List expansion is not performed, so you cannot use hostlists to
 create a list of headers, however both connection and message variable expansion
 
 List expansion is not performed, so you cannot use hostlists to
 create a list of headers, however both connection and message variable expansion


@@ -35057,13 +35268,11 @@ If the string does not start with a slash, it is used as the
 filename, and the default path is then used.
 .endlist
 The &%decode%& condition normally succeeds. It is only false for syntax
 filename, and the default path is then used.
 .endlist
 The &%decode%& condition normally succeeds. It is only false for syntax

-errors or unusual circumstances such as memory shortages. You can easily decode
-a file with its original, proposed filename using
-.code
-decode = $mime_filename
-.endd
-However, you should keep in mind that &$mime_filename$& might contain
-anything. If you place files outside of the default path, they are not
+errors or unusual circumstances such as memory shortages.
+The variable &$mime_filename$& will have the suggested name for the file.
+Note however that this might contain anything, and is very difficult
+to safely use as all or even part of the filename.
+If you place files outside of the default path, they are not

 automatically unlinked.
 
 For RFC822 attachments (these are messages attached to messages, with a
 automatically unlinked.
 
 For RFC822 attachments (these are messages attached to messages, with a


@@ -35378,9 +35587,10 @@ The arguments are as follows:
 (the -D file). The file is open for reading and writing, but updating it is not
 recommended. &*Warning*&: You must &'not'& close this file descriptor.
 
 (the -D file). The file is open for reading and writing, but updating it is not
 recommended. &*Warning*&: You must &'not'& close this file descriptor.
 

-The descriptor is positioned at character 19 of the file, which is the first
-character of the body itself, because the first 19 characters are the message
-id followed by &`-D`& and a newline. If you rewind the file, you should use the
+The descriptor is positioned at character 26 of the file, which is the first
+character of the body itself, because the first 26 characters (19 characters
+before Exim  4.97) are the message id followed by &`-D`& and a newline.
+If you rewind the file, you should use the

 macro SPOOL_DATA_START_OFFSET to reset to the start of the data, just in
 case this changes in some future version.
 .next
 macro SPOOL_DATA_START_OFFSET to reset to the start of the data, just in
 case this changes in some future version.
 .next


@@ -35772,7 +35982,7 @@ The third argument may be NULL, in which case the &%-oMas%& option is omitted.
 
 
 .vitem &*void&~debug_printf(char&~*,&~...)*&
 
 
 .vitem &*void&~debug_printf(char&~*,&~...)*&

-This is Exim's debugging function, with arguments as for &'(printf()'&. The
+This is Exim's debugging function, with arguments as for &'printf()'&. The

 output is written to the standard error stream. If no debugging is selected,
 calls to &'debug_printf()'& have no effect. Normally, you should make calls
 conditional on the &`local_scan`& debug selector by coding like this:
 output is written to the standard error stream. If no debugging is selected,
 calls to &'debug_printf()'& have no effect. Normally, you should make calls
 conditional on the &`local_scan`& debug selector by coding like this:


@@ -36496,8 +36706,6 @@ other MTAs, the way Exim handles line endings for all messages is now as
 follows:
 
 .ilist
 follows:
 
 .ilist

-LF not preceded by CR is treated as a line ending.
-.next

 CR is treated as a line ending; if it is immediately followed by LF, the LF
 is ignored.
 .next
 CR is treated as a line ending; if it is immediately followed by LF, the LF
 is ignored.
 .next


@@ -36512,7 +36720,10 @@ people trying to play silly games.
 .next
 If the first header line received in a message ends with CRLF, a subsequent
 bare LF in a header line is treated in the same way as a bare CR in a header
 .next
 If the first header line received in a message ends with CRLF, a subsequent
 bare LF in a header line is treated in the same way as a bare CR in a header

-line.
+line and a bare LF in a body line is replaced with a space.
+.next
+If the first header line received in a message does not end with CRLF, a subsequent
+LF not preceded by CR is treated as a line ending.

 .endlist
 
 
 .endlist
 
 


@@ -37162,12 +37373,8 @@ See the next section for more detail about error handling.
 .cindex "SMTP" "batching over TCP/IP"
 When a message is successfully delivered over a TCP/IP SMTP connection, Exim
 looks in the hints database for the transport to see if there are any queued
 .cindex "SMTP" "batching over TCP/IP"
 When a message is successfully delivered over a TCP/IP SMTP connection, Exim
 looks in the hints database for the transport to see if there are any queued

-messages waiting for the host to which it is connected. If it finds one, it
-creates a new Exim process using the &%-MC%& option (which can only be used by
-a process running as root or the Exim user) and passes the TCP/IP socket to it
-so that it can deliver another message using the same socket. The new process
-does only those deliveries that are routed to the connected host, and may in
-turn pass the socket on to a third process, and so on.
+messages waiting for the host to which it is connected.
+If it finds one, it arranges to attempt that message on the same connection.

 
 The &%connection_max_messages%& option of the &(smtp)& transport can be used to
 limit the number of messages sent down a single TCP/IP connection.
 
 The &%connection_max_messages%& option of the &(smtp)& transport can be used to
 limit the number of messages sent down a single TCP/IP connection.


@@ -37505,6 +37712,14 @@ RCPT failures.
 .subsection "The ETRN command" SECTETRN
 .cindex "ETRN" "processing"
 .cindex "ESMTP extensions" ETRN
 .subsection "The ETRN command" SECTETRN
 .cindex "ETRN" "processing"
 .cindex "ESMTP extensions" ETRN

+Most modern installations never need to use this.
+It is used for managing messages queued for an intermittently-connecting
+destination (eg. one using a dialup connection).
+
+.oindex "&%acl_smtp_etrn%&"
+The command is only available if permitted by an ACL
+specfied by the main-section &%acl_smtp_etrn%& option.
+

 RFC 1985 describes an ESMTP command called ETRN that is designed to
 overcome the security problems of the TURN command (which has fallen into
 disuse). When Exim receives an ETRN command on a TCP/IP connection, it runs
 RFC 1985 describes an ESMTP command called ETRN that is designed to
 overcome the security problems of the TURN command (which has fallen into
 disuse). When Exim receives an ETRN command on a TCP/IP connection, it runs


@@ -39095,7 +39310,7 @@ selection marked by asterisks:
 .irow &`deliver_time`&                 &nbsp; "time taken to attempt delivery"
 .irow &`delivery_size`&                        &nbsp; "add &`S=`&&'nnn'& to => lines"
 .irow &`dkim`&                         *       "DKIM verified domain on <= lines"
 .irow &`deliver_time`&                 &nbsp; "time taken to attempt delivery"
 .irow &`delivery_size`&                        &nbsp; "add &`S=`&&'nnn'& to => lines"
 .irow &`dkim`&                         *       "DKIM verified domain on <= lines"

-.irow &`dkim_verbose`&                 &nbsp; "separate full DKIM verification result line, per signature"
+.irow &`dkim_verbose`&                 &nbsp; "separate full DKIM verification result line, per signature; DKIM signing"

 .irow &`dnslist_defer`&                        *       "defers of DNS list (aka RBL) lookups"
 .irow &`dnssec`&                       &nbsp; "DNSSEC secured lookups"
 .irow &`etrn`&                         *       "ETRN commands"
 .irow &`dnslist_defer`&                        *       "defers of DNS list (aka RBL) lookups"
 .irow &`dnssec`&                       &nbsp; "DNSSEC secured lookups"
 .irow &`etrn`&                         *       "ETRN commands"


@@ -39139,7 +39354,7 @@ selection marked by asterisks:
 .irow &`tls_peerdn`&                   &nbsp; "TLS peer DN on <= and => lines"
 .irow &`tls_resumption`&               &nbsp; "append * to cipher field"
 .irow &`tls_sni`&                      &nbsp; "TLS SNI on <= lines"
 .irow &`tls_peerdn`&                   &nbsp; "TLS peer DN on <= and => lines"
 .irow &`tls_resumption`&               &nbsp; "append * to cipher field"
 .irow &`tls_sni`&                      &nbsp; "TLS SNI on <= lines"

-.irow &`unknown_in_list`&              &nbsp; "DNS lookup failed in list match"
+.irow &`unknown_in_list`&              &nbsp; "lookup failed in list match"

 .irow &`all`&                          &nbsp; "&*all of the above*&"
 .endtable
 See also the &%slow_lookup_log%& main configuration option,
 .irow &`all`&                          &nbsp; "&*all of the above*&"
 .endtable
 See also the &%slow_lookup_log%& main configuration option,


@@ -39185,19 +39400,19 @@ because the arguments are checked before the configuration file is read. The
 only way to log such cases is to interpose a script such as &_util/logargs.sh_&
 between the caller and Exim.
 .next
 only way to log such cases is to interpose a script such as &_util/logargs.sh_&
 between the caller and Exim.
 .next

-.cindex "log" "connection identifier"
-.new
-&%connection_identifier%&: An identifier for the accepted connection is added to
+.cindex log "connection identifier"
+.cindex connection "identifier logging"
+&%connection_id%&: An identifier for the accepted connection is added to

 connection start and end lines and to message accept lines.
 The identifier is tagged by Ci=.
 The value is PID-based, so will reset on reboot and will wrap.
 connection start and end lines and to message accept lines.
 The identifier is tagged by Ci=.
 The value is PID-based, so will reset on reboot and will wrap.

-.wen

 .next
 .next

-.cindex "log" "connection rejections"
+.cindex log "connection rejections"
+.cindex connection "rejection logging"

 &%connection_reject%&: A log entry is written whenever an incoming SMTP
 connection is rejected, for whatever reason.
 .next
 &%connection_reject%&: A log entry is written whenever an incoming SMTP
 connection is rejected, for whatever reason.
 .next

-.cindex "log" "delayed delivery"
+.cindex log "delayed delivery"

 .cindex "delayed delivery, logging"
 &%delay_delivery%&: A log entry is written whenever a delivery process is not
 started for an incoming message because the load is too high or too many
 .cindex "delayed delivery, logging"
 &%delay_delivery%&: A log entry is written whenever a delivery process is not
 started for an incoming message because the load is too high or too many


@@ -39223,6 +39438,8 @@ verifies successfully a tag of DKIM is added, with one of the verified domains.
 .cindex log "DKIM verification"
 .cindex DKIM "verification logging"
 &%dkim_verbose%&: A log entry is written for each attempted DKIM verification.
 .cindex log "DKIM verification"
 .cindex DKIM "verification logging"
 &%dkim_verbose%&: A log entry is written for each attempted DKIM verification.

+Also, on message delivery lines signing information (domain and selector)
+is added, tagged with DKIM=.

 .next
 .cindex "log" "dnslist defer"
 .cindex "DNS list" "logging defer"
 .next
 .cindex "log" "dnslist defer"
 .cindex "DNS list" "logging defer"


@@ -39560,7 +39777,8 @@ added to the log line, preceded by SNI=.
 .next
 .cindex "log" "DNS failure in list"
 &%unknown_in_list%&: This setting causes a log entry to be written when the
 .next
 .cindex "log" "DNS failure in list"
 &%unknown_in_list%&: This setting causes a log entry to be written when the

-result of a list match is failure because a DNS lookup failed.
+result of a list match is failure because a DNS lookup failed, or because
+a bad IP address was in the list.

 .endlist
 
 
 .endlist
 
 


@@ -40116,8 +40334,6 @@ for remote hosts
 The &'misc'& database is used for
 
 .ilist
 The &'misc'& database is used for
 
 .ilist

-Serializing ETRN runs (when &%smtp_etrn_serialize%& is set)
-.next

 Serializing delivery to a specific host (when &%serialize_hosts%& is set in an
 &(smtp)& transport)
 .next
 Serializing delivery to a specific host (when &%serialize_hosts%& is set in an
 &(smtp)& transport)
 .next


@@ -40125,11 +40341,13 @@ Limiting the concurrency of specific transports (when &%max_parallel%& is set
 in a transport)
 .next
 Recording EHLO-time facilities advertised by hosts
 in a transport)
 .next
 Recording EHLO-time facilities advertised by hosts

+.next
+Serializing ETRN runs (when &%smtp_etrn_serialize%& is set)

 .endlist
 
 
 
 .endlist
 
 
 

-.section "exim_dumpdb" "SECTdumpdb"
+.subsection "exim_dumpdb" "SECTdumpdb"

 .cindex "&'exim_dumpdb'&"
 The entire contents of a database are written to the standard output by the
 &'exim_dumpdb'& program,
 .cindex "&'exim_dumpdb'&"
 The entire contents of a database are written to the standard output by the
 &'exim_dumpdb'& program,


@@ -40171,7 +40389,7 @@ cross-references.
 
 
 
 
 
 

-.section "exim_tidydb" "SECTtidydb"
+.subsection "exim_tidydb" "SECTtidydb"

 .cindex "&'exim_tidydb'&"
 The &'exim_tidydb'& utility program is used to tidy up the contents of a hints
 database. If run with no options, it removes all records that are more than 30
 .cindex "&'exim_tidydb'&"
 The &'exim_tidydb'& utility program is used to tidy up the contents of a hints
 database. If run with no options, it removes all records that are more than 30


@@ -40220,7 +40438,7 @@ databases is likely to keep on increasing.
 
 
 
 
 
 

-.section "exim_fixdb" "SECTfixdb"
+.subsection "exim_fixdb" "SECTfixdb"

 .cindex "&'exim_fixdb'&"
 The &'exim_fixdb'& program is a utility for interactively modifying databases.
 Its main use is for testing Exim, but it might also be occasionally useful for
 .cindex "&'exim_fixdb'&"
 The &'exim_fixdb'& program is a utility for interactively modifying databases.
 Its main use is for testing Exim, but it might also be occasionally useful for


@@ -40849,20 +41067,31 @@ will be used during message reception.
 .next
 A queue runner process retains root privilege throughout its execution. Its
 job is to fork a controlled sequence of delivery processes.
 .next
 A queue runner process retains root privilege throughout its execution. Its
 job is to fork a controlled sequence of delivery processes.

+
+.next
+A delivery process retains root privilege throughout most of its execution.,
+including while the recipient addresses in a message are being routed.
+
+.ilist
+However, if a user's filter file has to be processed,
+this is done in a subprocess that runs under the individual user's uid and
+gid. A system filter is run as root unless &%system_filter_user%& is set.
+.endlist
+
+Any actual deliveries (that is, the transports themselves) are run in
+subprocesses which always change to a non-root uid and gid.
+.ilist
+For local
+deliveries this is typically the uid and gid of the owner of the mailbox.

 .next
 .next

-A delivery process retains root privilege throughout most of its execution,
-but any actual deliveries (that is, the transports themselves) are run in
-subprocesses which always change to a non-root uid and gid. For local
-deliveries this is typically the uid and gid of the owner of the mailbox; for
-remote deliveries, the Exim uid and gid are used. Once all the delivery
+For remote deliveries, the Exim uid and gid are used.
+.endlist
+
+Once all the delivery

 subprocesses have been run, a delivery process changes to the Exim uid and gid
 while doing post-delivery tidying up such as updating the retry database and
 generating bounce and warning messages.
 
 subprocesses have been run, a delivery process changes to the Exim uid and gid
 while doing post-delivery tidying up such as updating the retry database and
 generating bounce and warning messages.
 

-While the recipient addresses in a message are being routed, the delivery
-process runs as root. However, if a user's filter file has to be processed,
-this is done in a subprocess that runs under the individual user's uid and
-gid. A system filter is run as root unless &%system_filter_user%& is set.

 .next
 A process that is testing addresses (the &%-bt%& option) runs as root so that
 the routing is done in the same environment as a message delivery.
 .next
 A process that is testing addresses (the &%-bt%& option) runs as root so that
 the routing is done in the same environment as a message delivery.


@@ -41568,8 +41797,9 @@ Exim's DKIM implementation allows for
 .olist
 Signing outgoing messages: This function is implemented in the SMTP transport.
 It can co-exist with all other Exim features
 .olist
 Signing outgoing messages: This function is implemented in the SMTP transport.
 It can co-exist with all other Exim features

-(including transport filters)
-except cutthrough delivery.
+(including transport filters) except cutthrough delivery.
+However, signing options may not depend on headers modified by
+routers, the transport or a transport filter.

 .next
 Verifying signatures in incoming messages: This is implemented by an additional
 ACL (acl_smtp_dkim), which can be called several times per message, with
 .next
 Verifying signatures in incoming messages: This is implemented by an additional
 ACL (acl_smtp_dkim), which can be called several times per message, with


@@ -41674,8 +41904,9 @@ To generate keys under OpenSSL:
 openssl genrsa -out dkim_rsa.private 2048
 openssl rsa -in dkim_rsa.private -out /dev/stdout -pubout -outform PEM
 .endd
 openssl genrsa -out dkim_rsa.private 2048
 openssl rsa -in dkim_rsa.private -out /dev/stdout -pubout -outform PEM
 .endd

-The result file from the first command should be retained, and
-this option set to use it.
+The result file from the first command should be retained,
+permissions set so that Exim can read it,
+and this option set to use it.

 Take the base-64 lines from the output of the second command, concatenated,
 for the DNS TXT record.
 See section 3.6 of RFC6376 for the record specification.
 Take the base-64 lines from the output of the second command, concatenated,
 for the DNS TXT record.
 See section 3.6 of RFC6376 for the record specification.


@@ -41755,7 +41986,7 @@ variables here.
 .option dkim_sign_headers smtp string&!! "see below"
 If set, this option must expand to a colon-separated
 list of header names.
 .option dkim_sign_headers smtp string&!! "see below"
 If set, this option must expand to a colon-separated
 list of header names.

-Headers with these names, or the absence or such a header, will be included
+Headers with these names, or the absence of such a header, will be included

 in the message signature.
 When unspecified, the header names listed in RFC4871 will be used,
 whether or not each header is present in the message.
 in the message signature.
 When unspecified, the header names listed in RFC4871 will be used,
 whether or not each header is present in the message.


@@ -41777,10 +42008,9 @@ name will be appended.
 .option dkim_timestamps smtp integer&!! unset
 This option controls the inclusion of timestamp information in the signature.
 If not set, no such information will be included.
 .option dkim_timestamps smtp integer&!! unset
 This option controls the inclusion of timestamp information in the signature.
 If not set, no such information will be included.

-Otherwise, must be an unsigned number giving an offset in seconds from the current time
-for the expiry tag
-(eg. 1209600 for two weeks);
-both creation (t=) and expiry (x=) tags will be included.
+Otherwise, must be an unsigned number giving an offset in seconds from the
+current time for the expiry tag (e.g. 1209600 for two weeks); both creation
+(t=) and expiry (x=) tags will be included unless the offset is 0 (no expiry).

 
 RFC 6376 lists these tags as RECOMMENDED.
 
 
 RFC 6376 lists these tags as RECOMMENDED.
 


@@ -41790,8 +42020,9 @@ RFC 6376 lists these tags as RECOMMENDED.
 
 Verification of DKIM signatures in SMTP incoming email is done for all
 messages for which an ACL control &%dkim_disable_verify%& has not been set.
 
 Verification of DKIM signatures in SMTP incoming email is done for all
 messages for which an ACL control &%dkim_disable_verify%& has not been set.

+

 .cindex DKIM "selecting signature algorithms"
 .cindex DKIM "selecting signature algorithms"

-Individual classes of signature algorithm can be ignored by changing
+Individual classes of DKIM signature algorithm can be ignored by changing

 the main options &%dkim_verify_hashes%& or &%dkim_verify_keytypes%&.
 The &%dkim_verify_minimal%& option can be set to cease verification
 processing for a message once the first passing signature is found.
 the main options &%dkim_verify_hashes%& or &%dkim_verify_keytypes%&.
 The &%dkim_verify_minimal%& option can be set to cease verification
 processing for a message once the first passing signature is found.


@@ -41804,7 +42035,7 @@ For most purposes the default option settings suffice and the remainder
 of this section can be ignored.
 
 The results of verification are made available to the
 of this section can be ignored.
 
 The results of verification are made available to the

-&%acl_smtp_dkim%& ACL, which can examine and modify them.
+&%acl_smtp_dkim%& ACL, which (for complex needs) can examine and modify them.

 A missing ACL definition defaults to accept.
 By default, the ACL is called once for each
 syntactically(!) correct signature in the incoming message.
 A missing ACL definition defaults to accept.
 By default, the ACL is called once for each
 syntactically(!) correct signature in the incoming message.


@@ -41869,6 +42100,12 @@ an identity. This is one of the list items from the expanded main option
 &%dkim_verify_signers%& (see above).
 
 .vitem &%$dkim_verify_status%&
 &%dkim_verify_signers%& (see above).
 
 .vitem &%$dkim_verify_status%&

+So long as a DKIM ACL is defined
+(it need do no more than accept, which is the default),
+after all the DKIM ACL runs have completed, the value becomes a
+colon-separated list of the values after each run.
+The value is maintained for the MIME, PRDR and DATA ACLs.
+

 Within the DKIM ACL,
 a string describing the general status of the signature. One of
 .ilist
 Within the DKIM ACL,
 a string describing the general status of the signature. One of
 .ilist


@@ -41897,11 +42134,6 @@ hash-method or key-size:
        set dkim_verify_reason = hash too weak or key too short
 .endd
 
        set dkim_verify_reason = hash too weak or key too short
 .endd
 

-So long as a DKIM ACL is defined (it need do no more than accept),
-after all the DKIM ACL runs have completed, the value becomes a
-colon-separated list of the values after each run.
-This is maintained for the mime, prdr and data ACLs.
-

 .vitem &%$dkim_verify_reason%&
 A string giving a little bit more detail when &%$dkim_verify_status%& is either
 "fail" or "invalid". One of
 .vitem &%$dkim_verify_reason%&
 A string giving a little bit more detail when &%$dkim_verify_status%& is either
 "fail" or "invalid". One of


@@ -42026,13 +42258,15 @@ option.
 
 .endlist
 
 
 .endlist
 

-In addition, two ACL conditions are provided, usable only in a DKIM ACL:
+In addition, two ACL conditions are provided:

 
 .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
 
 .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 &%$dkim_cur_signer%&). This is typically used to restrict an ACL
+(reflected by &%$dkim_cur_signer%&).
+This condition is only usable in a DKIM ACL.
+This is typically used to restrict an ACL

 verb to a group of domains or identities. For example:
 
 .code
 verb to a group of domains or identities. For example:
 
 .code


@@ -42048,7 +42282,16 @@ for that check for empty &$h_DKIM-Signature:$& in the data ACL.
 
 .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 against the actual result of verification. This is typically used
+results against the actual result of verification,
+given by &$dkim_verify_status$& if that is non-empty or "none" if empty.
+This condition may be used in DKIM, MIME, PRDR and DATA ACLs.
+
+A basic verification might be:
+.code
+deny !dkim_status = pass:none:invalid
+.endd
+
+A more complex use could be

 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


@@ -42061,6 +42304,10 @@ deny sender_domains = paypal.com:paypal.de
 The possible status keywords are: 'none','invalid','fail' and 'pass'. Please
 see the documentation of the &%$dkim_verify_status%& expansion variable above
 for more information of what they mean.
 The possible status keywords are: 'none','invalid','fail' and 'pass'. Please
 see the documentation of the &%$dkim_verify_status%& expansion variable above
 for more information of what they mean.

+
+The condition is true if the status
+(or any of the list of status values)
+is any one of the supplied list.

 .endlist
 
 
 .endlist
 
 


@@ -42084,6 +42331,12 @@ This includes retransmissions done by traditional forwarders.
 SPF verification support is built into Exim if SUPPORT_SPF=yes is set in
 &_Local/Makefile_&.  The support uses the &_libspf2_& library
 &url(https://www.libspf2.org/).
 SPF verification support is built into Exim if SUPPORT_SPF=yes is set in
 &_Local/Makefile_&.  The support uses the &_libspf2_& library
 &url(https://www.libspf2.org/).

+.new
+.cindex "dynamic modules"
+The support can be built as a dynamic-load module if desired;
+see the comments in that Makefile.
+.wen
+

 There is no Exim involvement in the transmission of messages;
 publishing certain DNS records is all that is required.
 
 There is no Exim involvement in the transmission of messages;
 publishing certain DNS records is all that is required.
 


@@ -42257,10 +42510,16 @@ The lookup will return the same result strings as can appear in
 
 .subsection "SRS (Sender Rewriting Scheme)" SECTSRS
 .cindex SRS "sender rewriting scheme"
 
 .subsection "SRS (Sender Rewriting Scheme)" SECTSRS
 .cindex SRS "sender rewriting scheme"

+.cindex VERP "variable envelope return path"

 
 SRS can be used to modify sender addresses when forwarding so that
 SPF verification does not object to them.
 
 SRS can be used to modify sender addresses when forwarding so that
 SPF verification does not object to them.

-It operates by encoding the original envelope sender in a new
+It can also be used to identify a received bounce message as
+likely (or not) having been trigged by a message from the
+local system, and for identifying dead addresses in mailing lists.
+It is one implementation of a VERP (Variable Envelope Return Path) method.
+
+SRS operates by encoding the original envelope sender in a new

 sender local part and using a domain run by the forwarding site
 as the new domain for the sender.  Any DSN message should be returned
 to this new sender at the forwarding site, which can extract the
 sender local part and using a domain run by the forwarding site
 as the new domain for the sender.  Any DSN message should be returned
 to this new sender at the forwarding site, which can extract the


@@ -42313,11 +42572,9 @@ return false.
 If it is, the condition will return true and the variable
 &$srs_recipient$& will be set to the decoded (original) value.
 
 If it is, the condition will return true and the variable
 &$srs_recipient$& will be set to the decoded (original) value.
 

-.new

 If the second argument is empty then the condition returns true if
 the first argument is in valid SRS formet, else false.
 The variable &$srs_recipient$& is not set for this case.
 If the second argument is empty then the condition returns true if
 the first argument is in valid SRS formet, else false.
 The variable &$srs_recipient$& is not set for this case.

-.wen

 .endlist
 
 Example usage:
 .endlist
 
 Example usage:


@@ -42352,7 +42609,8 @@ Example usage:
     allow_fail
     data =      :fail: Invalid SRS recipient address
 
     allow_fail
     data =      :fail: Invalid SRS recipient address
 

-  #... further routers here
+  #... further routers here get inbound_srs-redirected recipients
+  # and any that were not SRS'd

 
 
   # transport; should look like the non-forward outbound
 
 
   # transport; should look like the non-forward outbound


@@ -42938,10 +43196,12 @@ Events have names which correspond to the point in process at which they fire.
 The name is placed in the variable &$event_name$& and the event action
 expansion must check this, as it will be called for every possible event type.
 
 The name is placed in the variable &$event_name$& and the event action
 expansion must check this, as it will be called for every possible event type.
 

+.new

 The current list of events is:
 .itable all 0 0 4 25* left 10* center 15* center 50* left
 .row auth:fail             after    both       "per driver per authentication attempt"
 .row dane:fail              after    transport  "per connection"
 The current list of events is:
 .itable all 0 0 4 25* left 10* center 15* center 50* left
 .row auth:fail             after    both       "per driver per authentication attempt"
 .row dane:fail              after    transport  "per connection"

+.row dns:fail               after    both       "per lookup"

 .row msg:complete           after    main       "per message"
 .row msg:defer              after    transport  "per message per delivery try"
 .row msg:delivery           after    transport  "per recipient"
 .row msg:complete           after    main       "per message"
 .row msg:defer              after    transport  "per message per delivery try"
 .row msg:delivery           after    transport  "per recipient"


@@ -42956,7 +43216,10 @@ The current list of events is:
 .row tls:fail:connect       after    main       "per connection"
 .row smtp:connect           after    transport  "per connection"
 .row smtp:ehlo              after    transport  "per connection"
 .row tls:fail:connect       after    main       "per connection"
 .row smtp:connect           after    transport  "per connection"
 .row smtp:ehlo              after    transport  "per connection"

+.row smtp:fail:protocol     after    main       "per connection"
+.row smtp:fail:syntax       after    main       "per connection"

 .endtable
 .endtable

+.wen

 New event types may be added in future.
 
 The event name is a colon-separated list, defining the type of
 New event types may be added in future.
 
 The event name is a colon-separated list, defining the type of


@@ -42972,9 +43235,11 @@ should define the event action.
 
 An additional variable, &$event_data$&, is filled with information varying
 with the event type:
 
 An additional variable, &$event_data$&, is filled with information varying
 with the event type:

+.new

 .itable all 0 0 2 20* left 80* left
 .row auth:fail           "smtp response"
 .row dane:fail            "failure reason"
 .itable all 0 0 2 20* left 80* left
 .row auth:fail           "smtp response"
 .row dane:fail            "failure reason"

+.row dns:fail             "failure reason, key and lookup-type"

 .row msg:defer            "error string"
 .row msg:delivery         "smtp confirmation message"
 .row msg:fail:internal    "failure reason"
 .row msg:defer            "error string"
 .row msg:delivery         "smtp confirmation message"
 .row msg:fail:internal    "failure reason"


@@ -42986,7 +43251,10 @@ with the event type:
 .row tls:fail:connect     "error string"
 .row smtp:connect         "smtp banner"
 .row smtp:ehlo            "smtp ehlo response"
 .row tls:fail:connect     "error string"
 .row smtp:connect         "smtp banner"
 .row smtp:ehlo            "smtp ehlo response"

+.row smtp:fail:protocol   "error string"
+.row smtp:fail:syntax     "error string"

 .endtable
 .endtable

+.wen

 
 The :defer events populate one extra variable: &$event_defer_errno$&.
 
 
 The :defer events populate one extra variable: &$event_defer_errno$&.
 


@@ -43016,14 +43284,17 @@ All other message types ignore the result string, and
 no other use is made of it.
 
 For a tcp:connect event, if the connection is being made to a proxy
 no other use is made of it.
 
 For a tcp:connect event, if the connection is being made to a proxy

-then the &$host_address$& and &$port$& variables will be that of the proxy and not
-the target system.
+then the &$host_address$& and &$host_port$& variables
+will be that of the proxy and not the target system.

 
 For tls:cert events, if GnuTLS is in use this will trigger only per
 chain element received on the connection.
 For OpenSSL it will trigger for every chain element including those
 loaded locally.
 
 
 For tls:cert events, if GnuTLS is in use this will trigger only per
 chain element received on the connection.
 For OpenSSL it will trigger for every chain element including those
 loaded locally.
 

+For dns:fail events from dnsdb lookups, a &"defer_never"& option does not
+affect the reporting of DNS_AGAIN.
+

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