Expansions: extract methods for JSON objects and arrays. Bug 2282

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

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 2de41c60671af23ce613b9e315f93e4565ffe395..1dfa55228b0dcf8f3ce8c7e485e4a91893a99dec 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -45,7 +45,7 @@
 . Update the Copyright year (only) when changing content.
 . /////////////////////////////////////////////////////////////////////////////
 
 . Update the Copyright year (only) when changing content.
 . /////////////////////////////////////////////////////////////////////////////
 

-.set previousversion "4.90"
+.set previousversion "4.91"

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


@@ -392,7 +392,7 @@ very wide interest.
 An &"easier"& discussion of Exim which provides more in-depth explanatory,
 introductory, and tutorial material can be found in a book entitled &'The Exim
 SMTP Mail Server'& (second edition, 2007), published by UIT Cambridge
 An &"easier"& discussion of Exim which provides more in-depth explanatory,
 introductory, and tutorial material can be found in a book entitled &'The Exim
 SMTP Mail Server'& (second edition, 2007), published by UIT Cambridge

-(&url(http://www.uit.co.uk/exim-book/)).
+(&url(https://www.uit.co.uk/exim-book/)).

 
 This book also contains a chapter that gives a general introduction to SMTP and
 Internet mail. Inevitably, however, the book is unlikely to be fully up-to-date
 
 This book also contains a chapter that gives a general introduction to SMTP and
 Internet mail. Inevitably, however, the book is unlikely to be fully up-to-date


@@ -448,31 +448,25 @@ available in other formats (HTML, PostScript, PDF, and Texinfo). Section
 .section "FTP and web sites" "SECID2"
 .cindex "web site"
 .cindex "FTP site"
 .section "FTP and web sites" "SECID2"
 .cindex "web site"
 .cindex "FTP site"

-.new

 The primary site for Exim source distributions is the &%exim.org%& FTP site,
 available over HTTPS, HTTP and FTP.  These services, and the &%exim.org%&
 website, are hosted at the University of Cambridge.
 The primary site for Exim source distributions is the &%exim.org%& FTP site,
 available over HTTPS, HTTP and FTP.  These services, and the &%exim.org%&
 website, are hosted at the University of Cambridge.

-.wen

 
 .cindex "wiki"
 .cindex "FAQ"
 As well as Exim distribution tar files, the Exim web site contains a number of
 differently formatted versions of the documentation. A recent addition to the
 
 .cindex "wiki"
 .cindex "FAQ"
 As well as Exim distribution tar files, the Exim web site contains a number of
 differently formatted versions of the documentation. A recent addition to the

-online information is the Exim wiki (&url(http://wiki.exim.org)),
+online information is the Exim wiki (&url(https://wiki.exim.org)),

 which contains what used to be a separate FAQ, as well as various other
 examples, tips, and know-how that have been contributed by Exim users.
 which contains what used to be a separate FAQ, as well as various other
 examples, tips, and know-how that have been contributed by Exim users.

-.new

 The wiki site should always redirect to the correct place, which is currently
 provided by GitHub, and is open to editing by anyone with a GitHub account.
 The wiki site should always redirect to the correct place, which is currently
 provided by GitHub, and is open to editing by anyone with a GitHub account.

-.wen

 
 .cindex Bugzilla
 An Exim Bugzilla exists at &url(https://bugs.exim.org). You can use
 this to report bugs, and also to add items to the wish list. Please search
 first to check that you are not duplicating a previous entry.
 
 .cindex Bugzilla
 An Exim Bugzilla exists at &url(https://bugs.exim.org). You can use
 this to report bugs, and also to add items to the wish list. Please search
 first to check that you are not duplicating a previous entry.

-.new

 Please do not ask for configuration help in the bug-tracker.
 Please do not ask for configuration help in the bug-tracker.

-.wen

 
 
 .section "Mailing lists" "SECID3"
 
 
 .section "Mailing lists" "SECID3"


@@ -493,7 +487,7 @@ If you are using a Debian distribution of Exim, you may wish to subscribe to
 the Debian-specific mailing list &'pkg-exim4-users@lists.alioth.debian.org'&
 via this web page:
 .display
 the Debian-specific mailing list &'pkg-exim4-users@lists.alioth.debian.org'&
 via this web page:
 .display

-&url(http://lists.alioth.debian.org/mailman/listinfo/pkg-exim4-users)
+&url(https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/pkg-exim4-users)

 .endd
 Please ask Debian-specific questions on this list and not on the general Exim
 lists.
 .endd
 Please ask Debian-specific questions on this list and not on the general Exim
 lists.


@@ -513,23 +507,21 @@ message to the &'exim-dev'& mailing list and have it discussed.
 .cindex "HTTPS download site"
 .cindex "distribution" "ftp site"
 .cindex "distribution" "https site"
 .cindex "HTTPS download site"
 .cindex "distribution" "ftp site"
 .cindex "distribution" "https site"

-.new

 The master distribution site for the Exim distribution is
 .display
 The master distribution site for the Exim distribution is
 .display

-&*https://downloads.exim.org/*&
+&url(https://downloads.exim.org/)

 .endd
 The service is available over HTTPS, HTTP and FTP.
 We encourage people to migrate to HTTPS.
 
 .endd
 The service is available over HTTPS, HTTP and FTP.
 We encourage people to migrate to HTTPS.
 

-The content served at &'https://downloads.exim.org/'& is identical to the
-content served at &'https://ftp.exim.org/pub/exim'& and
-&'ftp://ftp.exim.org/pub/exim'&.
+The content served at &url(https://downloads.exim.org/) is identical to the
+content served at &url(https://ftp.exim.org/pub/exim) and
+&url(ftp://ftp.exim.org/pub/exim).

 
 If accessing via a hostname containing &'ftp'&, then the file references that
 follow are relative to the &_exim_& directories at these sites.
 If accessing via the hostname &'downloads'& then the subdirectories described
 here are top-level directories.
 
 If accessing via a hostname containing &'ftp'&, then the file references that
 follow are relative to the &_exim_& directories at these sites.
 If accessing via the hostname &'downloads'& then the subdirectories described
 here are top-level directories.

-.wen

 
 There are now quite a number of independent mirror sites around
 the world. Those that I know about are listed in the file called &_Mirrors_&.
 
 There are now quite a number of independent mirror sites around
 the world. Those that I know about are listed in the file called &_Mirrors_&.


@@ -545,10 +537,8 @@ subdirectory, the current release can always be found in files called
 .endd
 where &'n.nn'& is the highest such version number in the directory. The three
 files contain identical data; the only difference is the type of compression.
 .endd
 where &'n.nn'& is the highest such version number in the directory. The three
 files contain identical data; the only difference is the type of compression.

-.new

 The &_.xz_& file is usually the smallest, while the &_.gz_& file is the
 most portable to old systems.
 The &_.xz_& file is usually the smallest, while the &_.gz_& file is the
 most portable to old systems.

-.wen

 
 .cindex "distribution" "signing details"
 .cindex "distribution" "public key"
 
 .cindex "distribution" "signing details"
 .cindex "distribution" "public key"


@@ -562,12 +552,10 @@ PGP key, a version of which can be found in the release directory in the file
 &_nigel-pubkey.asc_&.  All keys used will be available in public keyserver pools,
 such as &'pool.sks-keyservers.net'&.
 
 &_nigel-pubkey.asc_&.  All keys used will be available in public keyserver pools,
 such as &'pool.sks-keyservers.net'&.
 

-.new

 At time of last update, releases were being made by Jeremy Harris and signed
 with key &'0xBCE58C8CE41F32DF'&.  Other recent keys used for signing are those
 of Heiko Schlittermann, &'0x26101B62F69376CE'&,
 and of Phil Pennock, &'0x4D1E900E14C1CC04'&.
 At time of last update, releases were being made by Jeremy Harris and signed
 with key &'0xBCE58C8CE41F32DF'&.  Other recent keys used for signing are those
 of Heiko Schlittermann, &'0x26101B62F69376CE'&,
 and of Phil Pennock, &'0x4D1E900E14C1CC04'&.

-.wen

 
 The signatures for the tar bundles are in:
 .display
 
 The signatures for the tar bundles are in:
 .display


@@ -589,10 +577,8 @@ inside the &_exim4_& directory of the FTP site:
 &_exim-postscript-n.nn.tar.gz_&
 &_exim-texinfo-n.nn.tar.gz_&
 .endd
 &_exim-postscript-n.nn.tar.gz_&
 &_exim-texinfo-n.nn.tar.gz_&
 .endd

-.new

 These tar files contain only the &_doc_& directory, not the complete
 distribution, and are also available in &_.bz2_& and &_.xz_& forms.
 These tar files contain only the &_doc_& directory, not the complete
 distribution, and are also available in &_.bz2_& and &_.xz_& forms.

-.wen

 
 
 .section "Limitations" "SECID6"
 
 
 .section "Limitations" "SECID6"


@@ -785,7 +771,7 @@ Foundation; either version 2 of the License, or (at your option) any later
 version.
 This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
 the spec and sample code for cdb can be obtained from
 version.
 This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
 the spec and sample code for cdb can be obtained from

-&url(http://www.pobox.com/~djb/cdb.html). This implementation borrows
+&url(https://cr.yp.to/cdb.html). This implementation borrows

 some code from Dan Bernstein's implementation (which has no license
 restrictions applied to it).
 .endblockquote
 some code from Dan Bernstein's implementation (which has no license
 restrictions applied to it).
 .endblockquote


@@ -839,7 +825,7 @@ Redistributions of any form whatsoever must retain the following
 acknowledgment:
 
 &"This product includes software developed by Computing Services
 acknowledgment:
 
 &"This product includes software developed by Computing Services

-at Carnegie Mellon University (&url(http://www.cmu.edu/computing/)."&
+at Carnegie Mellon University (&url(https://www.cmu.edu/computing/)."&

 
 CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
 THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 
 CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
 THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY


@@ -1378,6 +1364,7 @@ order in which they are tested. The individual configuration options are
 described in more detail in chapter &<<CHAProutergeneric>>&.
 
 .ilist
 described in more detail in chapter &<<CHAProutergeneric>>&.
 
 .ilist

+.cindex affix "router precondition"

 The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
 the local parts handled by the router may or must have certain prefixes and/or
 suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
 The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
 the local parts handled by the router may or must have certain prefixes and/or
 suffixes. If a mandatory affix (prefix or suffix) is not present, the router is


@@ -1414,6 +1401,7 @@ of domains that it defines.
 .vindex "&$local_part_prefix$&"
 .vindex "&$local_part$&"
 .vindex "&$local_part_suffix$&"
 .vindex "&$local_part_prefix$&"
 .vindex "&$local_part$&"
 .vindex "&$local_part_suffix$&"

+.cindex affix "router precondition"

 If the &%local_parts%& option is set, the local part of the address must be in
 the set of local parts that it defines. If &%local_part_prefix%& or
 &%local_part_suffix%& is in use, the prefix or suffix is removed from the local
 If the &%local_parts%& option is set, the local part of the address must be in
 the set of local parts that it defines. If &%local_part_prefix%& or
 &%local_part_suffix%& is in use, the prefix or suffix is removed from the local


@@ -1710,7 +1698,7 @@ or set PCRE_CONFIG=yes to use the installed &(pcre-config)& command.
 If your operating system has no
 PCRE support then you will need to obtain and build the current PCRE
 from &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/).
 If your operating system has no
 PCRE support then you will need to obtain and build the current PCRE
 from &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/).

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

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


@@ -1763,14 +1751,18 @@ the traditional &'ndbm'& interface.
 .next
 To complicate things further, there are several very different versions of the
 Berkeley DB package. Version 1.85 was stable for a very long time, releases
 .next
 To complicate things further, there are several very different versions of the
 Berkeley DB package. Version 1.85 was stable for a very long time, releases

-2.&'x'& and 3.&'x'& were current for a while, but the latest versions are now
-numbered 4.&'x'&. Maintenance of some of the earlier releases has ceased. All
-versions of Berkeley DB can be obtained from
-&url(http://www.sleepycat.com/).
+2.&'x'& and 3.&'x'& were current for a while, but the latest versions when Exim last revamped support were numbered 4.&'x'&.
+Maintenance of some of the earlier releases has ceased. All versions of
+Berkeley DB could be obtained from
+&url(http://www.sleepycat.com/), which is now a redirect to their new owner's
+page with far newer versions listed.
+It is probably wise to plan to move your storage configurations away from
+Berkeley DB format, as today there are smaller and simpler alternatives more
+suited to Exim's usage model.

 .next
 .cindex "&'tdb'& DBM library"
 Yet another DBM library, called &'tdb'&, is available from
 .next
 .cindex "&'tdb'& DBM library"
 Yet another DBM library, called &'tdb'&, is available from

-&url(http://download.sourceforge.net/tdb). It has its own interface, and also
+&url(https://sourceforge.net/projects/tdb/files/). It has its own interface, and also

 operates on a single file.
 .endlist
 
 operates on a single file.
 .endlist
 


@@ -1883,7 +1875,7 @@ supports the &[iconv()]& function.
 
 However, some of the operating systems that supply &[iconv()]& do not support
 very many conversions. The GNU &%libiconv%& library (available from
 
 However, some of the operating systems that supply &[iconv()]& do not support
 very many conversions. The GNU &%libiconv%& library (available from

-&url(http://www.gnu.org/software/libiconv/)) can be installed on such
+&url(https://www.gnu.org/software/libiconv/)) can be installed on such

 systems to remedy this deficiency, as well as on systems that do not supply
 &[iconv()]& at all. After installing &%libiconv%&, you should add
 .code
 systems to remedy this deficiency, as well as on systems that do not supply
 &[iconv()]& at all. After installing &%libiconv%&, you should add
 .code


@@ -2910,12 +2902,14 @@ actually being delivered.
 
 .vitem &%-bfp%&&~<&'prefix'&>
 .oindex "&%-bfp%&"
 
 .vitem &%-bfp%&&~<&'prefix'&>
 .oindex "&%-bfp%&"

+.cindex affix "filter testing"

 This sets the prefix of the local part of the recipient address when a filter
 file is being tested by means of the &%-bf%& option. The default is an empty
 prefix.
 
 .vitem &%-bfs%&&~<&'suffix'&>
 .oindex "&%-bfs%&"
 This sets the prefix of the local part of the recipient address when a filter
 file is being tested by means of the &%-bf%& option. The default is an empty
 prefix.
 
 .vitem &%-bfs%&&~<&'suffix'&>
 .oindex "&%-bfs%&"

+.cindex affix "filter testing"

 This sets the suffix of the local part of the recipient address when a filter
 file is being tested by means of the &%-bf%& option. The default is an empty
 suffix.
 This sets the suffix of the local part of the recipient address when a filter
 file is being tested by means of the &%-bf%& option. The default is an empty
 suffix.


@@ -2971,7 +2965,7 @@ acceptable or not. See section &<<SECTcheckaccess>>&.
 Features such as authentication and encryption, where the client input is not
 plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
 specialized SMTP test program such as
 Features such as authentication and encryption, where the client input is not
 plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
 specialized SMTP test program such as

-&url(http://jetmore.org/john/code/#swaks,swaks).
+&url(https://www.jetmore.org/john/code/swaks/,swaks).

 
 .vitem &%-bhc%&&~<&'IP&~address'&>
 .oindex "&%-bhc%&"
 
 .vitem &%-bhc%&&~<&'IP&~address'&>
 .oindex "&%-bhc%&"


@@ -3187,10 +3181,8 @@ If invoked by an admin user, then &%macro%&, &%macro_list%& and &%macros%&
 are available, similarly to the drivers.  Because macros are sometimes used
 for storing passwords, this option is restricted.
 The output format is one item per line.
 are available, similarly to the drivers.  Because macros are sometimes used
 for storing passwords, this option is restricted.
 The output format is one item per line.

-.new

 For the "-bP macro <name>" form, if no such macro is found
 the exit status will be nonzero.
 For the "-bP macro <name>" form, if no such macro is found
 the exit status will be nonzero.

-.wen

 
 .vitem &%-bp%&
 .oindex "&%-bp%&"
 
 .vitem &%-bp%&
 .oindex "&%-bp%&"


@@ -3982,8 +3974,17 @@ the messages are active, their status is not altered. This option can be used
 only by an admin user or by the user who originally caused the message to be
 placed on the queue.
 
 only by an admin user or by the user who originally caused the message to be
 placed on the queue.
 

+. .new
+. .vitem &%-MS%&
+. .oindex "&%-MS%&"
+. .cindex REQUIRETLS
+. This option is used to request REQUIRETLS processing on the message.
+. It is used internally by Exim in conjunction with -E when generating
+. a bounce message.
+. .wen
+

 .vitem &%-Mset%&&~<&'message&~id'&>
 .vitem &%-Mset%&&~<&'message&~id'&>

-.oindex "&%-Mset%&
+.oindex "&%-Mset%&"

 .cindex "testing" "string expansion"
 .cindex "expansion" "testing"
 This option is useful only in conjunction with &%-be%& (that is, when testing
 .cindex "testing" "string expansion"
 .cindex "expansion" "testing"
 This option is useful only in conjunction with &%-be%& (that is, when testing


@@ -5083,6 +5084,7 @@ The following classes of macros are defined:
 &` _DRIVER_ROUTER_*           `&  router drivers
 &` _DRIVER_TRANSPORT_*        `&  transport drivers
 &` _DRIVER_AUTHENTICATOR_*    `&  authenticator drivers
 &` _DRIVER_ROUTER_*           `&  router drivers
 &` _DRIVER_TRANSPORT_*        `&  transport drivers
 &` _DRIVER_AUTHENTICATOR_*    `&  authenticator drivers

+&` _LOG_*                     `&  log_selector values

 &` _OPT_MAIN_*                `&  main config options
 &` _OPT_ROUTERS_*             `&  generic router options
 &` _OPT_TRANSPORTS_*          `&  generic transport options
 &` _OPT_MAIN_*                `&  main config options
 &` _OPT_ROUTERS_*             `&  generic router options
 &` _OPT_TRANSPORTS_*          `&  generic transport options


@@ -6341,6 +6343,9 @@ online Perl manpages, in
 many Perl reference books, and also in
 Jeffrey Friedl's &'Mastering Regular Expressions'&, which is published by
 O'Reilly (see &url(http://www.oreilly.com/catalog/regex2/)).
 many Perl reference books, and also in
 Jeffrey Friedl's &'Mastering Regular Expressions'&, which is published by
 O'Reilly (see &url(http://www.oreilly.com/catalog/regex2/)).

+. --- the http: URL here redirects to another page with the ISBN in the URL
+. --- where trying to use https: just redirects back to http:, so sticking
+. --- to the old URL for now.  2018-09-07.

 
 The documentation for the syntax and semantics of the regular expressions that
 are supported by PCRE is included in the PCRE distribution, and no further
 
 The documentation for the syntax and semantics of the regular expressions that
 are supported by PCRE is included in the PCRE distribution, and no further


@@ -6507,13 +6512,15 @@ The following single-key lookup types are implemented:
 string without a terminating binary zero. The cdb format is designed for
 indexed files that are read frequently and never updated, except by total
 re-creation. As such, it is particularly suitable for large files containing
 string without a terminating binary zero. The cdb format is designed for
 indexed files that are read frequently and never updated, except by total
 re-creation. As such, it is particularly suitable for large files containing

-aliases or other indexed data referenced by an MTA. Information about cdb can
-be found in several places:
+aliases or other indexed data referenced by an MTA. Information about cdb and
+tools for building the files can be found in several places:

 .display
 .display

-&url(http://www.pobox.com/~djb/cdb.html)
-&url(ftp://ftp.corpit.ru/pub/tinycdb/)
-&url(http://packages.debian.org/stable/utils/freecdb.html)
+&url(https://cr.yp.to/cdb.html)
+&url(http://www.corpit.ru/mjt/tinycdb.html)
+&url(https://packages.debian.org/stable/utils/freecdb)
+&url(https://github.com/philpennock/cdbtools) (in Go)

 .endd
 .endd

+. --- 2018-09-07: corpit.ru http:-only

 A cdb distribution is not needed in order to build Exim with cdb support,
 because the code for reading cdb files is included directly in Exim itself.
 However, no means of building or testing cdb files is provided with Exim, so
 A cdb distribution is not needed in order to build Exim with cdb support,
 because the code for reading cdb files is included directly in Exim itself.
 However, no means of building or testing cdb files is provided with Exim, so


@@ -6794,6 +6801,7 @@ not likely to be useful in normal operation.
 .next
 .cindex "whoson lookup type"
 .cindex "lookup" "whoson"
 .next
 .cindex "whoson lookup type"
 .cindex "lookup" "whoson"

+. --- still http:-only, 2018-09-07

 &(whoson)&: &'Whoson'& (&url(http://whoson.sourceforge.net)) is a protocol that
 allows a server to check whether a particular (dynamically allocated) IP
 address is currently allocated to a known (trusted) user and, optionally, to
 &(whoson)&: &'Whoson'& (&url(http://whoson.sourceforge.net)) is a protocol that
 allows a server to check whether a particular (dynamically allocated) IP
 address is currently allocated to a known (trusted) user and, optionally, to


@@ -7864,7 +7872,6 @@ ${lookup redis{set keyname ${quote_redis:objvalue plus}}}
 ${lookup redis{get keyname}}
 .endd
 
 ${lookup redis{get keyname}}
 .endd
 

-.new

 As of release 4.91, "lightweight" support for Redis Cluster is available.
 Requires &%redis_servers%& list to contain all the servers in the cluster, all
 of which must be reachable from the running exim instance. If the cluster has
 As of release 4.91, "lightweight" support for Redis Cluster is available.
 Requires &%redis_servers%& list to contain all the servers in the cluster, all
 of which must be reachable from the running exim instance. If the cluster has


@@ -7875,7 +7882,6 @@ When the Redis Cluster returns a "MOVED" response to a query, Exim does not
 immediately follow the redirection but treats the response as a DEFER, moving on
 to the next server in the &%redis_servers%& list until the correct server is
 reached.
 immediately follow the redirection but treats the response as a DEFER, moving on
 to the next server in the &%redis_servers%& list until the correct server is
 reached.

-.wen

 
 .ecindex IIDfidalo1
 .ecindex IIDfidalo2
 
 .ecindex IIDfidalo1
 .ecindex IIDfidalo2


@@ -9175,7 +9181,6 @@ the expansion result is an empty string.
 If the ACL returns defer the result is a forced-fail.  Otherwise the expansion fails.
 
 
 If the ACL returns defer the result is a forced-fail.  Otherwise the expansion fails.
 
 

-.new

 .vitem "&*${authresults{*&<&'authserv-id'&>&*}}*&"
 .cindex authentication "results header"
 .cindex headers "authentication-results:"
 .vitem "&*${authresults{*&<&'authserv-id'&>&*}}*&"
 .cindex authentication "results header"
 .cindex headers "authentication-results:"


@@ -9199,7 +9204,6 @@ 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.

-.wen

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


@@ -9370,6 +9374,27 @@ ${extract{Z}{A=... B=...}{$value} fail }
 This forces an expansion failure (see section &<<SECTforexpfai>>&);
 {<&'string2'&>} must be present for &"fail"& to be recognized.
 
 This forces an expansion failure (see section &<<SECTforexpfai>>&);
 {<&'string2'&>} must be present for &"fail"& to be recognized.
 

+.new
+.vitem "&*${extract json{*&<&'key'&>&*}{*&<&'string1'&>&*}{*&<&'string2'&>&*}&&&
+       {*&<&'string3'&>&*}}*&"
+.cindex "expansion" "extracting from JSON object"
+.cindex JSON expansions
+The key and <&'string1'&> are first expanded separately. Leading and trailing
+white space is removed from the key (but not from any of the strings). The key
+must not be empty and must not consist entirely of digits.
+The expanded <&'string1'&> must be of the form:
+.display
+{ <&'"key1"'&> : <&'value1'&> ,  <&'"key2"'&> , <&'value2'&> ... }
+.endd
+.vindex "&$value$&"
+The braces, commas and colons, and the quoting of the member name are required;
+the spaces are optional.
+Matching of the key against the member names is done case-sensitively.
+. XXX should be a UTF-8 compare
+
+The results of matching are handled as above.
+.wen
+

 
 .vitem "&*${extract{*&<&'number'&>&*}{*&<&'separators'&>&*}&&&
         {*&<&'string1'&>&*}{*&<&'string2'&>&*}{*&<&'string3'&>&*}}*&"
 
 .vitem "&*${extract{*&<&'number'&>&*}{*&<&'separators'&>&*}&&&
         {*&<&'string1'&>&*}{*&<&'string2'&>&*}{*&<&'string3'&>&*}}*&"


@@ -9402,6 +9427,19 @@ yields &"99"&. Two successive separators mean that the field between them is
 empty (for example, the fifth field above).
 
 
 empty (for example, the fifth field above).
 
 

+.new
+.vitem "&*${extract json{*&<&'number'&>&*}}&&&
+        {*&<&'string1'&>&*}{*&<&'string2'&>&*}{*&<&'string3'&>&*}}*&"
+.cindex "expansion" "extracting from JSON array"
+.cindex JSON expansions
+The <&'number'&> argument must consist entirely of decimal digits,
+apart from leading and trailing white space, which is ignored.
+
+Field selection and result handling is as above;
+there is no choice of field separator.
+.wen
+
+

 .vitem &*${filter{*&<&'string'&>&*}{*&<&'condition'&>&*}}*&
 .cindex "list" "selecting by condition"
 .cindex "expansion" "selecting from list by condition"
 .vitem &*${filter{*&<&'string'&>&*}{*&<&'condition'&>&*}}*&
 .cindex "list" "selecting by condition"
 .cindex "expansion" "selecting from list by condition"


@@ -9454,11 +9492,14 @@ letters appear. For example:
         &*$h_*&<&'header&~name'&>&*:*&" &&&
        "&*$bheader_*&<&'header&~name'&>&*:*&&~or&~&&&
         &*$bh_*&<&'header&~name'&>&*:*&" &&&
         &*$h_*&<&'header&~name'&>&*:*&" &&&
        "&*$bheader_*&<&'header&~name'&>&*:*&&~or&~&&&
         &*$bh_*&<&'header&~name'&>&*:*&" &&&

+       "&*$lheader_*&<&'header&~name'&>&*:*&&~or&~&&&
+        &*$lh_*&<&'header&~name'&>&*:*&"

        "&*$rheader_*&<&'header&~name'&>&*:*&&~or&~&&&
         &*$rh_*&<&'header&~name'&>&*:*&"
 .cindex "expansion" "header insertion"
 .vindex "&$header_$&"
 .vindex "&$bheader_$&"
        "&*$rheader_*&<&'header&~name'&>&*:*&&~or&~&&&
         &*$rh_*&<&'header&~name'&>&*:*&"
 .cindex "expansion" "header insertion"
 .vindex "&$header_$&"
 .vindex "&$bheader_$&"

+.vindex "&$lheader_$&"

 .vindex "&$rheader_$&"
 .cindex "header lines" "in expansion strings"
 .cindex "header lines" "character sets"
 .vindex "&$rheader_$&"
 .cindex "header lines" "in expansion strings"
 .cindex "header lines" "character sets"


@@ -9471,7 +9512,7 @@ The newline that terminates a header line is not included in the expansion, but
 internal newlines (caused by splitting the header line over several physical
 lines) may be present.
 
 internal newlines (caused by splitting the header line over several physical
 lines) may be present.
 

-The difference between &%rheader%&, &%bheader%&, and &%header%& is in the way
+The difference between the four pairs of expansions is in the way

 the data in the header line is interpreted.
 
 .ilist
 the data in the header line is interpreted.
 
 .ilist


@@ -9479,6 +9520,15 @@ the data in the header line is interpreted.
 &%rheader%& gives the original &"raw"& content of the header line, with no
 processing at all, and without the removal of leading and trailing white space.
 
 &%rheader%& gives the original &"raw"& content of the header line, with no
 processing at all, and without the removal of leading and trailing white space.
 

+.next
+.cindex "list" "of header lines"
+&%lheader%& gives a colon-separated list, one element per header when there
+are multiple headers with a given name.
+Any embedded colon characters within an element are doubled, so normal Exim
+list-processing facilities can be used.
+The terminating newline of each element is removed; in other respects
+the content is &"raw"&.
+

 .next
 .cindex "base64 encoding" "in header lines"
 &%bheader%& removes leading and trailing white space, and then decodes base64
 .next
 .cindex "base64 encoding" "in header lines"
 &%bheader%& removes leading and trailing white space, and then decodes base64


@@ -9636,9 +9686,10 @@ some of the braces:
 .code
 ${length_<n>:<string>}
 .endd
 .code
 ${length_<n>:<string>}
 .endd

-The result of this item is either the first <&'n'&> characters or the whole
+The result of this item is either the first <&'n'&> bytes or the whole

 of <&'string2'&>, whichever is the shorter. Do not confuse &%length%& with
 &%strlen%&, which gives the length of a string.
 of <&'string2'&>, whichever is the shorter. Do not confuse &%length%& with
 &%strlen%&, which gives the length of a string.

+All measurement is done in bytes and is not UTF-8 aware.

 
 
 .vitem "&*${listextract{*&<&'number'&>&*}&&&
 
 
 .vitem "&*${listextract{*&<&'number'&>&*}&&&


@@ -9886,15 +9937,26 @@ extend what can be done. Firstly, you can vary the timeout. For example:
 .code
 ${readsocket{/socket/name}{request string}{3s}}
 .endd
 .code
 ${readsocket{/socket/name}{request string}{3s}}
 .endd

+

 The third argument is a list of options, of which the first element is the timeout
 and must be present if the argument is given.
 Further elements are options of form &'name=value'&.
 The third argument is a list of options, of which the first element is the timeout
 and must be present if the argument is given.
 Further elements are options of form &'name=value'&.

-One option type is currently recognised, defining whether (the default)
+Two option types is currently recognised: shutdown and tls.
+The first defines whether (the default)

 or not a shutdown is done on the connection after sending the request.
 Example, to not do so (preferred, eg. by some webservers):
 .code
 ${readsocket{/socket/name}{request string}{3s:shutdown=no}}
 .endd
 or not a shutdown is done on the connection after sending the request.
 Example, to not do so (preferred, eg. by some webservers):
 .code
 ${readsocket{/socket/name}{request string}{3s:shutdown=no}}
 .endd

+.new
+The second, tls, controls the use of TLS on the connection.  Example:
+.code
+${readsocket{/socket/name}{request string}{3s:tls=yes}}
+.endd
+The default is to not use TLS.
+If it is enabled, a shutdown as descripbed above is never done.
+.wen
+

 A fourth argument allows you to change any newlines that are in the data
 that is read, in the same way as for &%readfile%& (see above). This example
 turns them into spaces:
 A fourth argument allows you to change any newlines that are in the data
 that is read, in the same way as for &%readfile%& (see above). This example
 turns them into spaces:


@@ -10059,6 +10121,8 @@ ${sg{1=A 4=D 3=C}{\N(\d+)=\N}{K\$1=}}
 yields &"K1=A K4=D K3=C"&. Note the use of &`\N`& to protect the contents of
 the regular expression from string expansion.
 
 yields &"K1=A K4=D K3=C"&. Note the use of &`\N`& to protect the contents of
 the regular expression from string expansion.
 

+The regular expression is compiled in 8-bit mode, working against bytes
+rather than any Unicode-aware character handling.

 
 
 .vitem &*${sort{*&<&'string'&>&*}{*&<&'comparator'&>&*}{*&<&'extractor'&>&*}}*&
 
 
 .vitem &*${sort{*&<&'string'&>&*}{*&<&'comparator'&>&*}{*&<&'extractor'&>&*}}*&


@@ -10115,11 +10179,11 @@ ${substr{3}{2}{$local_part}}
 If the starting offset is greater than the string length the result is the
 null string; if the length plus starting offset is greater than the string
 length, the result is the right-hand part of the string, starting from the
 If the starting offset is greater than the string length the result is the
 null string; if the length plus starting offset is greater than the string
 length, the result is the right-hand part of the string, starting from the

-given offset. The first character in the string has offset zero.
+given offset. The first byte (character) in the string has offset zero.

 
 The &%substr%& expansion item can take negative offset values to count
 
 The &%substr%& expansion item can take negative offset values to count

-from the right-hand end of its operand. The last character is offset -1, the
-second-last is offset -2, and so on. Thus, for example,
+from the right-hand end of its operand. The last byte (character) is offset -1,
+the second-last is offset -2, and so on. Thus, for example,

 .code
 ${substr{-5}{2}{1234567}}
 .endd
 .code
 ${substr{-5}{2}{1234567}}
 .endd


@@ -10136,7 +10200,7 @@ ${substr{-3}{2}{12}}
 yields &"1"&.
 
 When the second number is omitted from &%substr%&, the remainder of the string
 yields &"1"&.
 
 When the second number is omitted from &%substr%&, the remainder of the string

-is taken if the offset is positive. If it is negative, all characters in the
+is taken if the offset is positive. If it is negative, all bytes (characters) in the

 string preceding the offset point are taken. For example, an offset of -1 and
 no length, as in these semantically identical examples:
 .code
 string preceding the offset point are taken. For example, an offset of -1 and
 no length, as in these semantically identical examples:
 .code


@@ -10145,13 +10209,15 @@ ${substr{-1}{abcde}}
 .endd
 yields all but the last character of the string, that is, &"abcd"&.
 
 .endd
 yields all but the last character of the string, that is, &"abcd"&.
 

+All measurement is done in bytes and is not UTF-8 aware.
+

 
 
 .vitem "&*${tr{*&<&'subject'&>&*}{*&<&'characters'&>&*}&&&
         {*&<&'replacements'&>&*}}*&"
 .cindex "expansion" "character translation"
 .cindex "&%tr%& expansion item"
 
 
 .vitem "&*${tr{*&<&'subject'&>&*}{*&<&'characters'&>&*}&&&
         {*&<&'replacements'&>&*}}*&"
 .cindex "expansion" "character translation"
 .cindex "&%tr%& expansion item"

-This item does single-character translation on its subject string. The second
+This item does single-character (in bytes) translation on its subject string. The second

 argument is a list of characters to be translated in the subject string. Each
 matching character is replaced by the corresponding character from the
 replacement list. For example
 argument is a list of characters to be translated in the subject string. Each
 matching character is replaced by the corresponding character from the
 replacement list. For example


@@ -10162,6 +10228,9 @@ yields &`1b3de1`&. If there are duplicates in the second character string, the
 last occurrence is used. If the third string is shorter than the second, its
 last character is replicated. However, if it is empty, no translation takes
 place.
 last occurrence is used. If the third string is shorter than the second, its
 last character is replicated. However, if it is empty, no translation takes
 place.

+
+All character handling is done in bytes and is not UTF-8 aware.
+

 .endlist
 
 
 .endlist
 
 


@@ -10181,6 +10250,8 @@ The string is interpreted as an RFC 2822 address, as it might appear in a
 header line, and the effective address is extracted from it. If the string does
 not parse successfully, the result is empty.
 
 header line, and the effective address is extracted from it. If the string does
 not parse successfully, the result is empty.
 

+The parsing correctly handles SMTPUTF8 Unicode in the string.
+

 
 .vitem &*${addresses:*&<&'string'&>&*}*&
 .cindex "expansion" "RFC 2822 address handling"
 
 .vitem &*${addresses:*&<&'string'&>&*}*&
 .cindex "expansion" "RFC 2822 address handling"


@@ -10224,7 +10295,7 @@ It does not see the comma because it's still encoded as "=2C".  The second
 example below is passed the contents of &`$header_from:`&, meaning it gets
 de-mimed. Exim sees the decoded "," so it treats it as &*two*& email addresses.
 The third example shows that the presence of a comma is skipped when it is
 example below is passed the contents of &`$header_from:`&, meaning it gets
 de-mimed. Exim sees the decoded "," so it treats it as &*two*& email addresses.
 The third example shows that the presence of a comma is skipped when it is

-quoted.
+quoted.  The fourth example shows SMTPUTF8 handling.

 .code
 # exim -be '${addresses:From: \
 =?iso-8859-2?Q?Last=2C_First?= <user@example.com>}'
 .code
 # exim -be '${addresses:From: \
 =?iso-8859-2?Q?Last=2C_First?= <user@example.com>}'


@@ -10233,6 +10304,8 @@ user@example.com
 Last:user@example.com
 # exim -be '${addresses:From: "Last, First" <user@example.com>}'
 user@example.com
 Last:user@example.com
 # exim -be '${addresses:From: "Last, First" <user@example.com>}'
 user@example.com

+# exim -be '${addresses:フィル <フィリップ@example.jp>}'
+フィリップ@example.jp

 .endd
 
 .vitem &*${base32:*&<&'digits'&>&*}*&
 .endd
 
 .vitem &*${base32:*&<&'digits'&>&*}*&


@@ -10422,7 +10495,7 @@ abbreviation &%h%& can be used when &%hash%& is used as an operator.
 .cindex "expansion" "hex to base64"
 .cindex "&%hex2b64%& expansion item"
 This operator converts a hex string into one that is base64 encoded. This can
 .cindex "expansion" "hex to base64"
 .cindex "&%hex2b64%& expansion item"
 This operator converts a hex string into one that is base64 encoded. This can

-be useful for processing the output of the MD5 and SHA-1 hashing functions.
+be useful for processing the output of the various hashing functions.

 
 
 
 
 
 


@@ -10464,6 +10537,7 @@ This forces the letters in the string into lower-case, for example:
 .code
 ${lc:$local_part}
 .endd
 .code
 ${lc:$local_part}
 .endd

+Case is defined per the system C locale.

 
 .vitem &*${length_*&<&'number'&>&*:*&<&'string'&>&*}*&
 .cindex "expansion" "string truncation"
 
 .vitem &*${length_*&<&'number'&>&*:*&<&'string'&>&*}*&
 .cindex "expansion" "string truncation"


@@ -10477,6 +10551,7 @@ ${length{<number>}{<string>}}
 See the description of the general &%length%& item above for details. Note that
 &%length%& is not the same as &%strlen%&. The abbreviation &%l%& can be used
 when &%length%& is used as an operator.
 See the description of the general &%length%& item above for details. Note that
 &%length%& is not the same as &%strlen%&. The abbreviation &%l%& can be used
 when &%length%& is used as an operator.

+All measurement is done in bytes and is not UTF-8 aware.

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


@@ -10504,6 +10579,7 @@ matching list is returned.
 The string is interpreted as an RFC 2822 address and the local part is
 extracted from it. If the string does not parse successfully, the result is
 empty.
 The string is interpreted as an RFC 2822 address and the local part is
 extracted from it. If the string does not parse successfully, the result is
 empty.

+The parsing correctly handles SMTPUTF8 Unicode in the string.

 
 
 .vitem &*${mask:*&<&'IP&~address'&>&*/*&<&'bit&~count'&>&*}*&
 
 
 .vitem &*${mask:*&<&'IP&~address'&>&*/*&<&'bit&~count'&>&*}*&


@@ -10586,6 +10662,10 @@ example, a plus sign would not cause quoting (but it would for &%quote%&).
 If you are creating a new email address from the contents of &$local_part$&
 (or any other unknown data), you should always use this operator.
 
 If you are creating a new email address from the contents of &$local_part$&
 (or any other unknown data), you should always use this operator.
 

+This quoting determination is not SMTPUTF8-aware, thus quoting non-ASCII data
+will likely use the quoting form.
+Thus &'${quote_local_part:フィル}'& will always become &'"フィル"'&.
+

 
 .vitem &*${quote_*&<&'lookup-type'&>&*:*&<&'string'&>&*}*&
 .cindex "quoting" "lookup-specific"
 
 .vitem &*${quote_*&<&'lookup-type'&>&*:*&<&'string'&>&*}*&
 .cindex "quoting" "lookup-specific"


@@ -10715,10 +10795,8 @@ with 256 being the default.
 
 The &%sha3%& expansion item is only supported if Exim has been
 compiled with GnuTLS 3.5.0 or later,
 
 The &%sha3%& expansion item is only supported if Exim has been
 compiled with GnuTLS 3.5.0 or later,

-.new

 or OpenSSL 1.1.1 or later.
 The macro "_CRYPTO_HASH_SHA3" will be defined if it is supported.
 or OpenSSL 1.1.1 or later.
 The macro "_CRYPTO_HASH_SHA3" will be defined if it is supported.

-.wen

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


@@ -10751,6 +10829,7 @@ Now deprecated, a synonym for the &%base64%& expansion operator.
 .cindex "&%strlen%& expansion item"
 The item is replace by the length of the expanded string, expressed as a
 decimal number. &*Note*&: Do not confuse &%strlen%& with &%length%&.
 .cindex "&%strlen%& expansion item"
 The item is replace by the length of the expanded string, expressed as a
 decimal number. &*Note*&: Do not confuse &%strlen%& with &%length%&.

+All measurement is done in bytes and is not UTF-8 aware.

 
 
 .vitem &*${substr_*&<&'start'&>&*_*&<&'length'&>&*:*&<&'string'&>&*}*&
 
 
 .vitem &*${substr_*&<&'start'&>&*_*&<&'length'&>&*:*&<&'string'&>&*}*&


@@ -10765,6 +10844,7 @@ ${substr{<start>}{<length>}{<string>}}
 .endd
 See the description of the general &%substr%& item above for details. The
 abbreviation &%s%& can be used when &%substr%& is used as an operator.
 .endd
 See the description of the general &%substr%& item above for details. The
 abbreviation &%s%& can be used when &%substr%& is used as an operator.

+All measurement is done in bytes and is not UTF-8 aware.

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


@@ -10787,6 +10867,7 @@ number of larger units and output in Exim's normal time format, for example,
 .cindex "expansion" "case forcing"
 .cindex "&%uc%& expansion item"
 This forces the letters in the string into upper-case.
 .cindex "expansion" "case forcing"
 .cindex "&%uc%& expansion item"
 This forces the letters in the string into upper-case.

+Case is defined per the system C locale.

 
 .vitem &*${utf8clean:*&<&'string'&>&*}*&
 .cindex "correction of invalid utf-8 sequences in strings"
 
 .vitem &*${utf8clean:*&<&'string'&>&*}*&
 .cindex "correction of invalid utf-8 sequences in strings"


@@ -10795,6 +10876,20 @@ This forces the letters in the string into upper-case.
 .cindex "expansion" "utf-8 forcing"
 .cindex "&%utf8clean%& expansion item"
 This replaces any invalid utf-8 sequence in the string by the character &`?`&.
 .cindex "expansion" "utf-8 forcing"
 .cindex "&%utf8clean%& expansion item"
 This replaces any invalid utf-8 sequence in the string by the character &`?`&.

+.new
+In versions of Exim before 4.92, this did not correctly do so for a truncated
+final codepoint's encoding, and the character would be silently dropped.
+If you must handle detection of this scenario across both sets of Exim behavior,
+the complexity will depend upon the task.
+For instance, to detect if the first character is multibyte and a 1-byte
+extraction can be successfully used as a path component (as is common for
+dividing up delivery folders), you might use:
+.code
+condition = ${if inlist{${utf8clean:${length_1:$local_part}}}{:?}{yes}{no}}
+.endd
+(which will false-positive if the first character of the local part is a
+literal question mark).
+.wen

 
 .vitem "&*${utf8_domain_to_alabel:*&<&'string'&>&*}*&" &&&
        "&*${utf8_domain_from_alabel:*&<&'string'&>&*}*&" &&&
 
 .vitem "&*${utf8_domain_to_alabel:*&<&'string'&>&*}*&" &&&
        "&*${utf8_domain_from_alabel:*&<&'string'&>&*}*&" &&&


@@ -11017,7 +11112,8 @@ the header name must be terminated by a colon if white space does not follow.
 .cindex "&%eqi%& expansion condition"
 The two substrings are first expanded. The condition is true if the two
 resulting strings are identical. For &%eq%& the comparison includes the case of
 .cindex "&%eqi%& expansion condition"
 The two substrings are first expanded. The condition is true if the two
 resulting strings are identical. For &%eq%& the comparison includes the case of

-letters, whereas for &%eqi%& the comparison is case-independent.
+letters, whereas for &%eqi%& the comparison is case-independent, where
+case is defined per the system C locale.

 
 .vitem &*exists&~{*&<&'file&~name'&>&*}*&
 .cindex "expansion" "file existence test"
 
 .vitem &*exists&~{*&<&'file&~name'&>&*}*&
 .cindex "expansion" "file existence test"


@@ -11080,6 +11176,7 @@ The two substrings are first expanded. The condition is true if the first
 string is lexically greater than or equal to the second string. For &%ge%& the
 comparison includes the case of letters, whereas for &%gei%& the comparison is
 case-independent.
 string is lexically greater than or equal to the second string. For &%ge%& the
 comparison includes the case of letters, whereas for &%gei%& the comparison is
 case-independent.

+Case and collation order are defined per the system C locale.

 
 .vitem &*gt&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*& &&&
        &*gti&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&
 
 .vitem &*gt&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*& &&&
        &*gti&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&


@@ -11091,6 +11188,7 @@ The two substrings are first expanded. The condition is true if the first
 string is lexically greater than the second string. For &%gt%& the comparison
 includes the case of letters, whereas for &%gti%& the comparison is
 case-independent.
 string is lexically greater than the second string. For &%gt%& the comparison
 includes the case of letters, whereas for &%gti%& the comparison is
 case-independent.

+Case and collation order are defined per the system C locale.

 
 .vitem &*inlist&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*& &&&
        &*inlisti&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&
 
 .vitem &*inlist&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*& &&&
        &*inlisti&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&


@@ -11099,6 +11197,7 @@ case-independent.
 Both strings are expanded; the second string is treated as a list of simple
 strings; if the first string is a member of the second, then the condition
 is true.
 Both strings are expanded; the second string is treated as a list of simple
 strings; if the first string is a member of the second, then the condition
 is true.

+For the case-independent &%inlisti%& condition, case is defined per the system C locale.

 
 These are simpler to use versions of the more powerful &*forany*& condition.
 Examples, and the &*forany*& equivalents:
 
 These are simpler to use versions of the more powerful &*forany*& condition.
 Examples, and the &*forany*& equivalents:


@@ -11165,6 +11264,7 @@ The two substrings are first expanded. The condition is true if the first
 string is lexically less than or equal to the second string. For &%le%& the
 comparison includes the case of letters, whereas for &%lei%& the comparison is
 case-independent.
 string is lexically less than or equal to the second string. For &%le%& the
 comparison includes the case of letters, whereas for &%lei%& the comparison is
 case-independent.

+Case and collation order are defined per the system C locale.

 
 .vitem &*lt&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*& &&&
        &*lti&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&
 
 .vitem &*lt&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*& &&&
        &*lti&~{*&<&'string1'&>&*}{*&<&'string2'&>&*}*&


@@ -11176,6 +11276,7 @@ The two substrings are first expanded. The condition is true if the first
 string is lexically less than the second string. For &%lt%& the comparison
 includes the case of letters, whereas for &%lti%& the comparison is
 case-independent.
 string is lexically less than the second string. For &%lt%& the comparison
 includes the case of letters, whereas for &%lti%& the comparison is
 case-independent.

+Case and collation order are defined per the system C locale.

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


@@ -11202,6 +11303,8 @@ metacharacter, but if there is no circumflex, the expression is not anchored,
 and it may match anywhere in the subject, not just at the start. If you want
 the pattern to match at the end of the subject, you must include the &`$`&
 metacharacter at an appropriate point.
 and it may match anywhere in the subject, not just at the start. If you want
 the pattern to match at the end of the subject, you must include the &`$`&
 metacharacter at an appropriate point.

+All character handling is done in bytes and is not UTF-8 aware,
+but we might change this in a future Exim release.

 
 .cindex "numerical variables (&$1$& &$2$& etc)" "in &%if%& expansion"
 At the start of an &%if%& expansion the values of the numeric variable
 
 .cindex "numerical variables (&$1$& &$2$& etc)" "in &%if%& expansion"
 At the start of an &%if%& expansion the values of the numeric variable


@@ -11316,7 +11419,7 @@ matched using &%match_ip%&.
 .cindex "expansion" "PAM authentication test"
 .cindex "&%pam%& expansion condition"
 &'Pluggable Authentication Modules'&
 .cindex "expansion" "PAM authentication test"
 .cindex "&%pam%& expansion condition"
 &'Pluggable Authentication Modules'&

-(&url(http://www.kernel.org/pub/linux/libs/pam/)) are a facility that is
+(&url(https://mirrors.edge.kernel.org/pub/linux/libs/pam/)) are a facility that is

 available in the latest releases of Solaris and in some GNU/Linux
 distributions. The Exim support, which is intended for use in conjunction with
 the SMTP AUTH command, is available only if Exim is compiled with
 available in the latest releases of Solaris and in some GNU/Linux
 distributions. The Exim support, which is intended for use in conjunction with
 the SMTP AUTH command, is available only if Exim is compiled with


@@ -11349,11 +11452,7 @@ server_condition = ${if pam{$auth2:${sg{$auth3}{:}{::}}}}
 In some operating systems, PAM authentication can be done only from a process
 running as root. Since Exim is running as the Exim user when receiving
 messages, this means that PAM cannot be used directly in those systems.
 In some operating systems, PAM authentication can be done only from a process
 running as root. Since Exim is running as the Exim user when receiving
 messages, this means that PAM cannot be used directly in those systems.

-A patched version of the &'pam_unix'& module that comes with the
-Linux PAM package is available from &url(http://www.e-admin.de/pam_exim/).
-The patched module allows one special uid/gid combination, in addition to root,
-to authenticate. If you build the patched module to allow the Exim user and
-group, PAM can then be used from an Exim authenticator.
+. --- 2018-09-07: the pam_exim modified variant has gone, removed claims re using Exim via that

 
 
 .vitem &*pwcheck&~{*&<&'string1'&>&*:*&<&'string2'&>&*}*&
 
 
 .vitem &*pwcheck&~{*&<&'string1'&>&*:*&<&'string2'&>&*}*&


@@ -11625,10 +11724,8 @@ When a message is submitted locally (that is, not over a TCP connection)
 the value of &$authenticated_id$& is normally the login name of the calling
 process. However, a trusted user can override this by means of the &%-oMai%&
 command line option.
 the value of &$authenticated_id$& is normally the login name of the calling
 process. However, a trusted user can override this by means of the &%-oMai%&
 command line option.

-.new

 This second case also sets up inforamtion used by the
 &$authresults$& expansion item.
 This second case also sets up inforamtion used by the
 &$authresults$& expansion item.

-.wen

 
 .vitem &$authenticated_fail_id$&
 .cindex "authentication" "fail" "id"
 
 .vitem &$authenticated_fail_id$&
 .cindex "authentication" "fail" "id"


@@ -11968,11 +12065,9 @@ lookup succeeds, but there is a lookup problem such as a timeout when checking
 the result, the name is not accepted, and &$host_lookup_deferred$& is set to
 &"1"&. See also &$sender_host_name$&.
 
 the result, the name is not accepted, and &$host_lookup_deferred$& is set to
 &"1"&. See also &$sender_host_name$&.
 

-.new

 .cindex authentication "expansion item"
 Performing these checks sets up information used by the
 &$authresults$& expansion item.
 .cindex authentication "expansion item"
 Performing these checks sets up information used by the
 &$authresults$& expansion item.

-.wen

 
 
 .vitem &$host_lookup_failed$&
 
 
 .vitem &$host_lookup_failed$&


@@ -12040,6 +12135,7 @@ once.
 
 .vindex "&$local_part_prefix$&"
 .vindex "&$local_part_suffix$&"
 
 .vindex "&$local_part_prefix$&"
 .vindex "&$local_part_suffix$&"

+.cindex affix variables

 If a local part prefix or suffix has been recognized, it is not included in the
 value of &$local_part$& during routing and subsequent delivery. The values of
 any prefix or suffix are in &$local_part_prefix$& and
 If a local part prefix or suffix has been recognized, it is not included in the
 value of &$local_part$& during routing and subsequent delivery. The values of
 any prefix or suffix are in &$local_part_prefix$& and


@@ -12092,6 +12188,7 @@ variable expands to nothing.
 
 .vitem &$local_part_prefix$&
 .vindex "&$local_part_prefix$&"
 
 .vitem &$local_part_prefix$&
 .vindex "&$local_part_prefix$&"

+.cindex affix variables

 When an address is being routed or delivered, and a
 specific prefix for the local part was recognized, it is available in this
 variable, having been removed from &$local_part$&.
 When an address is being routed or delivered, and a
 specific prefix for the local part was recognized, it is available in this
 variable, having been removed from &$local_part$&.


@@ -12926,7 +13023,6 @@ A number of variables whose names start with &$spam$& are available when Exim
 is compiled with the content-scanning extension. For details, see section
 &<<SECTscanspamass>>&.
 
 is compiled with the content-scanning extension. For details, see section
 &<<SECTscanspamass>>&.
 

-.new

 .vitem &$spf_header_comment$& &&&
        &$spf_received$& &&&
        &$spf_result$& &&&
 .vitem &$spf_header_comment$& &&&
        &$spf_received$& &&&
        &$spf_result$& &&&


@@ -12934,7 +13030,6 @@ is compiled with the content-scanning extension. For details, see section
        &$spf_smtp_comment$&
 These variables are only available if Exim is built with SPF support.
 For details see section &<<SECSPF>>&.
        &$spf_smtp_comment$&
 These variables are only available if Exim is built with SPF support.
 For details see section &<<SECSPF>>&.

-.wen

 
 .vitem &$spool_directory$&
 .vindex "&$spool_directory$&"
 
 .vitem &$spool_directory$&
 .vindex "&$spool_directory$&"


@@ -13889,6 +13984,7 @@ listed in more than one group.
 .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""&"

+.row &%dns_cname_loops%&             "follow CNAMEs returned by resolver"

 .row &%dns_csa_search_limit%&        "control CSA parent search depth"
 .row &%dns_csa_use_reverse%&         "en/disable CSA IP reverse search"
 .row &%header_maxsize%&              "total size of message header"
 .row &%dns_csa_search_limit%&        "control CSA parent search depth"
 .row &%dns_csa_use_reverse%&         "en/disable CSA IP reverse search"
 .row &%header_maxsize%&              "total size of message header"


@@ -14147,7 +14243,7 @@ feel that in today's Internet, this causes more problems than it solves.
 It now defaults to true.
 A more detailed analysis of the issues is provided by Dan Bernstein:
 .display
 It now defaults to true.
 A more detailed analysis of the issues is provided by Dan Bernstein:
 .display

-&url(http://cr.yp.to/smtp/8bitmime.html)
+&url(https://cr.yp.to/smtp/8bitmime.html)

 .endd
 
 To log received 8BITMIME status use
 .endd
 
 To log received 8BITMIME status use


@@ -14791,6 +14887,19 @@ This option controls whether or not an IP address, given as a CSA domain, is
 reversed and looked up in the reverse DNS, as described in more detail in
 section &<<SECTverifyCSA>>&.
 
 reversed and looked up in the reverse DNS, as described in more detail in
 section &<<SECTverifyCSA>>&.
 

+.new
+.option dns_cname_loops main integer 1
+.cindex DNS "CNAME following"
+This option controls the following of CNAME chains, needed if the resolver does
+not do it internally.
+As of 2018 most should, and the default can be left.
+If you have an ancient one, a value of 10 is likely needed.
+
+The default value of one CNAME-follow is needed
+thanks to the observed return for an MX request,
+given no MX presence but a CNAME to an A, of the CNAME.
+.wen
+

 
 .option dns_dnssec_ok main integer -1
 .cindex "DNS" "resolver options"
 
 .option dns_dnssec_ok main integer -1
 .cindex "DNS" "resolver options"


@@ -15110,12 +15219,12 @@ server. This reduces security slightly, but improves interworking with older
 implementations of TLS.
 
 
 implementations of TLS.
 
 

-option gnutls_allow_auto_pkcs11 main boolean unset
+.option gnutls_allow_auto_pkcs11 main boolean unset

 This option will let GnuTLS (2.12.0 or later) autoload PKCS11 modules with
 the p11-kit configuration files in &_/etc/pkcs11/modules/_&.
 
 See
 This option will let GnuTLS (2.12.0 or later) autoload PKCS11 modules with
 the p11-kit configuration files in &_/etc/pkcs11/modules/_&.
 
 See

-&url(http://www.gnutls.org/manual/gnutls.html#Smart-cards-and-HSMs)
+&url(https://www.gnutls.org/manual/gnutls.html#Smart-cards-and-HSMs)

 for documentation.
 
 
 for documentation.
 
 


@@ -16932,11 +17041,9 @@ See section &<<SECTscanspamass>>& for more details.
 
 
 
 
 
 

-.new

 .option spf_guess main string "v=spf1 a/24 mx/24 ptr ?all"
 This option is available when Exim is compiled with SPF support.
 See section &<<SECSPF>>& for more details.
 .option spf_guess main string "v=spf1 a/24 mx/24 ptr ?all"
 This option is available when Exim is compiled with SPF support.
 See section &<<SECSPF>>& for more details.

-.wen

 
 
 
 
 
 


@@ -17259,13 +17366,11 @@ generated for every connection.
 This option specifies a certificate revocation list. The expanded value must
 be the name of a file that contains CRLs in PEM format.
 
 This option specifies a certificate revocation list. The expanded value must
 be the name of a file that contains CRLs in PEM format.
 

-.new

 Under OpenSSL the option can specify a directory with CRL files.
 
 &*Note:*& Under OpenSSL the option must, if given, supply a CRL
 for each signing element of the certificate chain (i.e. all but the leaf).
 For the file variant this can be multiple PEM blocks in the one file.
 Under OpenSSL the option can specify a directory with CRL files.
 
 &*Note:*& Under OpenSSL the option must, if given, supply a CRL
 for each signing element of the certificate chain (i.e. all but the leaf).
 For the file variant this can be multiple PEM blocks in the one file.

-.wen

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


@@ -17392,18 +17497,16 @@ Certificate Authority.
 
 Usable for GnuTLS 3.4.4 or 3.3.17 or OpenSSL 1.1.0 (or later).
 
 
 Usable for GnuTLS 3.4.4 or 3.3.17 or OpenSSL 1.1.0 (or later).
 

-.new

 For GnuTLS 3.5.6 or later the expanded value of this option can be a list
 of files, to match a list given for the &%tls_certificate%& option.
 The ordering of the two lists must match.
 For GnuTLS 3.5.6 or later the expanded value of this option can be a list
 of files, to match a list given for the &%tls_certificate%& option.
 The ordering of the two lists must match.

-.wen

 
 
 .option tls_on_connect_ports main "string list" unset
 .cindex SSMTP
 .cindex SMTPS
 This option specifies a list of incoming SSMTP (aka SMTPS) ports that should
 
 
 .option tls_on_connect_ports main "string list" unset
 .cindex SSMTP
 .cindex SMTPS
 This option specifies a list of incoming SSMTP (aka SMTPS) ports that should

-operate the obsolete SSMTP (SMTPS) protocol, where a TLS session is immediately
+operate the SSMTP (SMTPS) protocol, where a TLS session is immediately

 set up without waiting for the client to issue a STARTTLS command. For
 further details, see section &<<SECTsupobssmt>>&.
 
 set up without waiting for the client to issue a STARTTLS command. For
 further details, see section &<<SECTsupobssmt>>&.
 


@@ -18201,6 +18304,7 @@ and &%user%& and the discussion in chapter &<<CHAPenvironment>>&.
 
 
 .option local_part_prefix routers&!? "string list" unset
 
 
 .option local_part_prefix routers&!? "string list" unset

+.cindex affix "router precondition"

 .cindex "router" "prefix for local part"
 .cindex "prefix" "for local part, used in router"
 If this option is set, the router is skipped unless the local part starts with
 .cindex "router" "prefix for local part"
 .cindex "prefix" "for local part, used in router"
 If this option is set, the router is skipped unless the local part starts with


@@ -18859,9 +18963,7 @@ records.
 MX records of equal priority are sorted by Exim into a random order. Exim then
 looks for address records for the host names obtained from MX or SRV records.
 When a host has more than one IP address, they are sorted into a random order,
 MX records of equal priority are sorted by Exim into a random order. Exim then
 looks for address records for the host names obtained from MX or SRV records.
 When a host has more than one IP address, they are sorted into a random order,

-.new

 except that IPv6 addresses are sorted before IPv4 addresses. If all the
 except that IPv6 addresses are sorted before IPv4 addresses. If all the

-.wen

 IP addresses found are discarded by a setting of the &%ignore_target_hosts%&
 generic option, the router declines.
 
 IP addresses found are discarded by a setting of the &%ignore_target_hosts%&
 generic option, the router declines.
 


@@ -18994,7 +19096,6 @@ However, it will result in any message with mistyped domains
 also being queued.
 
 
 also being queued.
 
 

-.new

 .option ipv4_only "string&!!" unset
 .cindex IPv6 disabling
 .cindex DNS "IPv6 disabling"
 .option ipv4_only "string&!!" unset
 .cindex IPv6 disabling
 .cindex DNS "IPv6 disabling"


@@ -19010,7 +19111,6 @@ The string is expanded, and if the result is anything but a forced failure,
 or an empty string, or one of the strings “0” or “no” or “false”
 (checked without regard to the case of the letters),
 A records are sorted before AAAA records (inverting the default).
 or an empty string, or one of the strings “0” or “no” or “false”
 (checked without regard to the case of the letters),
 A records are sorted before AAAA records (inverting the default).

-.wen

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


@@ -19637,12 +19737,10 @@ also look in &_/etc/hosts_& or other sources of information.
 &%bydns%&: look up address records for the hosts directly in the DNS; fail if
 no address records are found. If there is a temporary DNS error (such as a
 timeout), delivery is deferred.
 &%bydns%&: look up address records for the hosts directly in the DNS; fail if
 no address records are found. If there is a temporary DNS error (such as a
 timeout), delivery is deferred.

-.new

 .next
 &%ipv4_only%&: in direct DNS lookups, look up only A records.
 .next
 &%ipv4_prefer%&: in direct DNS lookups, sort A records before AAAA records.
 .next
 &%ipv4_only%&: in direct DNS lookups, look up only A records.
 .next
 &%ipv4_prefer%&: in direct DNS lookups, sort A records before AAAA records.

-.wen

 .endlist
 
 For example:
 .endlist
 
 For example:


@@ -23968,7 +24066,6 @@ For testing purposes, this value can be overridden by the &%-oB%& command line
 option.
 
 
 option.
 
 

-.new

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


@@ -23983,7 +24080,6 @@ TLS cipherlist configuration stronger will increase security, rather than
 counter-intuitively decreasing it.
 If the option expands to be empty or is forced to fail, then it will
 be treated as unset and &%tls_require_ciphers%& will be used instead.
 counter-intuitively decreasing it.
 If the option expands to be empty or is forced to fail, then it will
 be treated as unset and &%tls_require_ciphers%& will be used instead.

-.wen

 
 
 .option data_timeout smtp time 5m
 
 
 .option data_timeout smtp time 5m


@@ -23992,14 +24088,15 @@ the message. As a result, the overall timeout for a message depends on the size
 of the message. Its value must not be zero. See also &%final_timeout%&.
 
 
 of the message. Its value must not be zero. See also &%final_timeout%&.
 
 

+.option dkim_canon smtp string&!! unset

 .option dkim_domain smtp string list&!! unset
 .option dkim_domain smtp string list&!! unset

-.option dkim_selector smtp string&!! unset
+.option dkim_hash smtp string&!! sha256
+.option dkim_identity smtp string&!! unset

 .option dkim_private_key smtp string&!! unset
 .option dkim_private_key smtp string&!! unset

-.option dkim_canon smtp string&!! unset
+.option dkim_selector smtp string&!! unset

 .option dkim_strict smtp string&!! unset
 .option dkim_sign_headers smtp string&!! "per RFC"
 .option dkim_strict smtp string&!! unset
 .option dkim_sign_headers smtp string&!! "per RFC"

-.option dkim_hash smtp string&!! sha256
-.option dkim_identity smtp string&!! unset
+.option dkim_timestamps smtp string&!! unset

 DKIM signing options.  For details see section &<<SECDKIMSIGN>>&.
 
 
 DKIM signing options.  For details see section &<<SECDKIMSIGN>>&.
 
 


@@ -24307,7 +24404,6 @@ 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

 .option hosts_require_dane smtp "host list&!!" unset
 .cindex DANE "transport options"
 .cindex DANE "requiring for certain servers"
 .option hosts_require_dane smtp "host list&!!" unset
 .cindex DANE "transport options"
 .cindex DANE "requiring for certain servers"


@@ -24316,7 +24412,6 @@ TLSA record is present for any host matching the list,
 and that a DANE-verified TLS connection is made.
 There will be no fallback to in-clear communication.
 See section &<<SECDANE>>&.
 and that a DANE-verified TLS connection is made.
 There will be no fallback to in-clear communication.
 See section &<<SECDANE>>&.

-.wen

 
 .option hosts_require_ocsp smtp "host list&!!" unset
 .cindex "TLS" "requiring for certain servers"
 
 .option hosts_require_ocsp smtp "host list&!!" unset
 .cindex "TLS" "requiring for certain servers"


@@ -24347,7 +24442,6 @@ This option provides a list of servers to which, provided they announce
 CHUNKING support, Exim will attempt to use BDAT commands rather than DATA.
 BDAT will not be used in conjunction with a transport filter.
 
 CHUNKING support, Exim will attempt to use BDAT commands rather than DATA.
 BDAT will not be used in conjunction with a transport filter.
 

-.new

 .option hosts_try_dane smtp "host list&!!" unset
 .cindex DANE "transport options"
 .cindex DANE "attempting for certain servers"
 .option hosts_try_dane smtp "host list&!!" unset
 .cindex DANE "transport options"
 .cindex DANE "attempting for certain servers"


@@ -24357,7 +24451,6 @@ If found and verified by DNSSEC,
 a DANE-verified TLS connection is made to that host;
 there will be no fallback to in-clear communication.
 See section &<<SECDANE>>&.
 a DANE-verified TLS connection is made to that host;
 there will be no fallback to in-clear communication.
 See section &<<SECDANE>>&.

-.wen

 
 .option hosts_try_fastopen smtp "host list&!!" unset
 .cindex "fast open, TCP" "enabling, in client"
 
 .option hosts_try_fastopen smtp "host list&!!" unset
 .cindex "fast open, TCP" "enabling, in client"


@@ -24715,6 +24808,16 @@ The &%tls_verify_certificates%& option must also be set.
 If both this option and &%tls_try_verify_hosts%& are unset
 operation is as if this option selected all hosts.
 
 If both this option and &%tls_try_verify_hosts%& are unset
 operation is as if this option selected all hosts.
 

+.new
+.option utf8_downconvert smtp integer!! unset
+.cindex utf8 "address downconversion"
+.cindex i18n "utf8 address downconversion"
+If built with internationalization support,
+this option controls conversion of UTF-8 in message addresses
+to a-label form.
+For details see section &<<SECTi18nMTA>>&.
+.wen
+

 
 
 
 
 
 


@@ -26164,11 +26267,9 @@ public name) of the authenticator driver that successfully authenticated the
 client from which the message was received. This variable is empty if there was
 no successful authentication.
 
 client from which the message was received. This variable is empty if there was
 no successful authentication.
 

-.new

 .cindex authentication "expansion item"
 Successful authentication sets up information used by the
 &$authresults$& expansion item.
 .cindex authentication "expansion item"
 Successful authentication sets up information used by the
 &$authresults$& expansion item.

-.wen

 
 
 
 
 
 


@@ -26679,8 +26780,8 @@ fixed_cram:
 .scindex IIDcyrauth2 "authenticators" "&(cyrus_sasl)&"
 .cindex "Cyrus" "SASL library"
 .cindex "Kerberos"
 .scindex IIDcyrauth2 "authenticators" "&(cyrus_sasl)&"
 .cindex "Cyrus" "SASL library"
 .cindex "Kerberos"

-The code for this authenticator was provided by Matthew Byng-Maddick of A L
-Digital Ltd (&url(http://www.aldigital.co.uk)).
+The code for this authenticator was provided by Matthew Byng-Maddick while
+at A L Digital Ltd.

 
 The &(cyrus_sasl)& authenticator provides server support for the Cyrus SASL
 library implementation of the RFC 2222 (&"Simple Authentication and Security
 
 The &(cyrus_sasl)& authenticator provides server support for the Cyrus SASL
 library implementation of the RFC 2222 (&"Simple Authentication and Security


@@ -26790,7 +26891,7 @@ authenticator only. There is only one option:
 
 .option server_socket dovecot string unset
 
 
 .option server_socket dovecot string unset
 

-This option must specify the socket that is the interface to Dovecot
+This option must specify the UNIX socket that is the interface to Dovecot

 authentication. The &%public_name%& option must specify an authentication
 mechanism that Dovecot is configured to support. You can have several
 authenticators for different mechanisms. For example:
 authentication. The &%public_name%& option must specify an authentication
 mechanism that Dovecot is configured to support. You can have several
 authenticators for different mechanisms. For example:


@@ -26840,15 +26941,17 @@ without code changes in Exim.
 
 
 .option server_channelbinding gsasl boolean false
 
 
 .option server_channelbinding gsasl boolean false

+Do not set this true without consulting a cryptographic engineer.
+

 Some authentication mechanisms are able to use external context at both ends
 of the session to bind the authentication to that context, and fail the
 authentication process if that context differs.  Specifically, some TLS
 ciphersuites can provide identifying information about the cryptographic
 context.
 
 Some authentication mechanisms are able to use external context at both ends
 of the session to bind the authentication to that context, and fail the
 authentication process if that context differs.  Specifically, some TLS
 ciphersuites can provide identifying information about the cryptographic
 context.
 

-This means that certificate identity and verification becomes a non-issue,
-as a man-in-the-middle attack will cause the correct client and server to
-see different identifiers and authentication will fail.
+This should have meant that certificate identity and verification becomes a
+non-issue, as a man-in-the-middle attack will cause the correct client and
+server to see different identifiers and authentication will fail.

 
 This is currently only supported when using the GnuTLS library.  This is
 only usable by mechanisms which support "channel binding"; at time of
 
 This is currently only supported when using the GnuTLS library.  This is
 only usable by mechanisms which support "channel binding"; at time of


@@ -26856,7 +26959,11 @@ writing, that's the SCRAM family.
 
 This defaults off to ensure smooth upgrade across Exim releases, in case
 this option causes some clients to start failing.  Some future release
 
 This defaults off to ensure smooth upgrade across Exim releases, in case
 this option causes some clients to start failing.  Some future release

-of Exim may switch the default to be true.
+of Exim might have switched the default to be true.
+
+However, Channel Binding in TLS has proven to be broken in current versions.
+Do not plan to rely upon this feature for security, ever, without consulting
+with a subject matter expert (a cryptographic engineer).

 
 
 .option server_hostname gsasl string&!! "see below"
 
 
 .option server_hostname gsasl string&!! "see below"


@@ -27038,7 +27145,7 @@ The &(spa)& authenticator provides client support for Microsoft's &'Secure
 Password Authentication'& mechanism,
 which is also sometimes known as NTLM (NT LanMan). The code for client side of
 this authenticator was contributed by Marc Prud'hommeaux, and much of it is
 Password Authentication'& mechanism,
 which is also sometimes known as NTLM (NT LanMan). The code for client side of
 this authenticator was contributed by Marc Prud'hommeaux, and much of it is

-taken from the Samba project (&url(http://www.samba.org)). The code for the
+taken from the Samba project (&url(https://www.samba.org/)). The code for the

 server side was subsequently contributed by Tom Kistner. The mechanism works as
 follows:
 
 server side was subsequently contributed by Tom Kistner. The mechanism works as
 follows:
 


@@ -27438,7 +27545,10 @@ the size of the generated prime, so it might still be too large.
 .oindex "&%tls_require_ciphers%&" "OpenSSL"
 There is a function in the OpenSSL library that can be passed a list of cipher
 suites before the cipher negotiation takes place. This specifies which ciphers
 .oindex "&%tls_require_ciphers%&" "OpenSSL"
 There is a function in the OpenSSL library that can be passed a list of cipher
 suites before the cipher negotiation takes place. This specifies which ciphers

-are acceptable. The list is colon separated and may contain names like
+.new
+are acceptable for TLS versions prior to 1.3.
+.wen
+The list is colon separated and may contain names like

 DES-CBC3-SHA. Exim passes the expanded value of &%tls_require_ciphers%&
 directly to this function call.
 Many systems will install the OpenSSL manual-pages, so you may have
 DES-CBC3-SHA. Exim passes the expanded value of &%tls_require_ciphers%&
 directly to this function call.
 Many systems will install the OpenSSL manual-pages, so you may have


@@ -27503,6 +27613,18 @@ This example will prefer ECDSA-authenticated ciphers over RSA ones:
 tls_require_ciphers = ECDSA:RSA:!COMPLEMENTOFDEFAULT
 .endd
 
 tls_require_ciphers = ECDSA:RSA:!COMPLEMENTOFDEFAULT
 .endd
 

+.new
+For TLS version 1.3 the control available is less fine-grained
+and Exim does not provide access to it at present.
+The value of the &%tls_require_ciphers%& option is ignored when
+TLS version 1.3 is negotiated.
+
+As of writing the library default cipher suite list for TLSv1.3 is
+.code
+TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256
+.endd
+.wen
+

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


@@ -27529,11 +27651,11 @@ aware of future feature enhancements of GnuTLS.
 
 Documentation of the strings accepted may be found in the GnuTLS manual, under
 "Priority strings".  This is online as
 
 Documentation of the strings accepted may be found in the GnuTLS manual, under
 "Priority strings".  This is online as

-&url(http://www.gnutls.org/manual/html_node/Priority-Strings.html),
+&url(https://www.gnutls.org/manual/html_node/Priority-Strings.html),

 but beware that this relates to GnuTLS 3, which may be newer than the version
 installed on your system.  If you are using GnuTLS 3,
 then the example code
 but beware that this relates to GnuTLS 3, which may be newer than the version
 installed on your system.  If you are using GnuTLS 3,
 then the example code

-&url(http://www.gnutls.org/manual/gnutls.html#Listing-the-ciphersuites-in-a-priority-string)
+&url(https://www.gnutls.org/manual/gnutls.html#Listing-the-ciphersuites-in-a-priority-string)

 on that site can be used to test a given string.
 
 For example:
 on that site can be used to test a given string.
 
 For example:


@@ -27685,7 +27807,7 @@ session with a client, you must set either &%tls_verify_hosts%& or
 apply to all TLS connections. For any host that matches one of these options,
 Exim requests a certificate as part of the setup of the TLS session. The
 contents of the certificate are verified by comparing it with a list of
 apply to all TLS connections. For any host that matches one of these options,
 Exim requests a certificate as part of the setup of the TLS session. The
 contents of the certificate are verified by comparing it with a list of

-expected certificates.
+expected trust-anchors or certificates.

 These may be the system default set (depending on library version),
 an explicit file or,
 depending on library version, a directory, identified by
 These may be the system default set (depending on library version),
 an explicit file or,
 depending on library version, a directory, identified by


@@ -27702,6 +27824,9 @@ openssl x509 -hash -noout -in /cert/file
 .endd
 where &_/cert/file_& contains a single certificate.
 
 .endd
 where &_/cert/file_& contains a single certificate.
 

+There is no checking of names of the client against the certificate
+Subject Name or Subject Alternate Names.
+

 The difference between &%tls_verify_hosts%& and &%tls_try_verify_hosts%& is
 what happens if the client does not supply a certificate, or if the certificate
 does not match any of the certificates in the collection named by
 The difference between &%tls_verify_hosts%& and &%tls_try_verify_hosts%& is
 what happens if the client does not supply a certificate, or if the certificate
 does not match any of the certificates in the collection named by


@@ -27863,6 +27988,11 @@ The &%tls_verify_hosts%& and &%tls_try_verify_hosts%& options restrict
 certificate verification to the listed servers.  Verification either must
 or need not succeed respectively.
 
 certificate verification to the listed servers.  Verification either must
 or need not succeed respectively.
 

+The &%tls_verify_cert_hostnames%& option lists hosts for which additional
+checks are made: that the host name (the one in the DNS A record)
+is valid for the certificate.
+The option defaults to always checking.
+

 The &(smtp)& transport has two OCSP-related options:
 &%hosts_require_ocsp%&; a host-list for which a Certificate Status
 is requested and required for the connection to proceed.  The default
 The &(smtp)& transport has two OCSP-related options:
 &%hosts_require_ocsp%&; a host-list for which a Certificate Status
 is requested and required for the connection to proceed.  The default


@@ -28029,22 +28159,29 @@ connections to new processes if TLS has been used.
 .section "Certificates and all that" "SECTcerandall"
 .cindex "certificate" "references to discussion"
 In order to understand fully how TLS works, you need to know about
 .section "Certificates and all that" "SECTcerandall"
 .cindex "certificate" "references to discussion"
 In order to understand fully how TLS works, you need to know about

-certificates, certificate signing, and certificate authorities. This is not the
-place to give a tutorial, especially as I do not know very much about it
-myself. Some helpful introduction can be found in the FAQ for the SSL addition
-to Apache, currently at
+certificates, certificate signing, and certificate authorities.
+This is a large topic and an introductory guide is unsuitable for the Exim
+reference manual, so instead we provide pointers to existing documentation.
+
+The Apache web-server was for a long time the canonical guide, so their
+documentation is a good place to start; their SSL module's Introduction
+document is currently at

 .display
 .display

-&url(http://www.modssl.org/docs/2.7/ssl_faq.html#ToC24)
+&url(https://httpd.apache.org/docs/current/ssl/ssl_intro.html)

 .endd
 .endd

-Other parts of the &'modssl'& documentation are also helpful, and have
-links to further files.
-Eric Rescorla's book, &'SSL and TLS'&, published by Addison-Wesley (ISBN
-0-201-61598-3), contains both introductory and more in-depth descriptions.
-Some sample programs taken from the book are available from
+and their FAQ is at

 .display
 .display

-&url(http://www.rtfm.com/openssl-examples/)
+&url(https://httpd.apache.org/docs/current/ssl/ssl_faq.html)

 .endd
 
 .endd
 

+Eric Rescorla's book, &'SSL and TLS'&, published by Addison-Wesley (ISBN
+0-201-61598-3) in 2001, contains both introductory and more in-depth
+descriptions.
+More recently Ivan Ristić's book &'Bulletproof SSL and TLS'&,
+published by Feisty Duck (ISBN 978-1907117046) in 2013 is good.
+Ivan is the author of the popular TLS testing tools at
+&url(https://www.ssllabs.com/).
+

 
 .section "Certificate chains" "SECID186"
 The file named by &%tls_certificate%& may contain more than one
 
 .section "Certificate chains" "SECID186"
 The file named by &%tls_certificate%& may contain more than one


@@ -28115,13 +28252,12 @@ signed with that self-signed certificate.
 For information on creating self-signed CA certificates and using them to sign
 user certificates, see the &'General implementation overview'& chapter of the
 Open-source PKI book, available online at
 For information on creating self-signed CA certificates and using them to sign
 user certificates, see the &'General implementation overview'& chapter of the
 Open-source PKI book, available online at

-&url(http://ospkibook.sourceforge.net/).
+&url(https://sourceforge.net/projects/ospkibook/).

 .ecindex IIDencsmtp1
 .ecindex IIDencsmtp2
 
 
 
 .ecindex IIDencsmtp1
 .ecindex IIDencsmtp2
 
 
 

-.new

 .section DANE "SECDANE"
 .cindex DANE
 DNS-based Authentication of Named Entities, as applied to SMTP over TLS, provides assurance to a client that
 .section DANE "SECDANE"
 .cindex DANE
 DNS-based Authentication of Named Entities, as applied to SMTP over TLS, provides assurance to a client that


@@ -28154,20 +28290,48 @@ Support for client-side operation of DANE can be included at compile time by def
 in &_Local/Makefile_&.
 If it has been included, the macro "_HAVE_DANE" will be defined.
 
 in &_Local/Makefile_&.
 If it has been included, the macro "_HAVE_DANE" will be defined.
 

-The TLSA record for the server may have "certificate usage" of DANE-TA(2) or DANE-EE(3).  The latter specifies
-the End Entity directly, i.e. the certificate involved is that of the server (and should be the sole one transmitted
-during the TLS handshake); this is appropriate for a single system, using a self-signed certificate.
+The TLSA record for the server may have "certificate usage" of DANE-TA(2) or DANE-EE(3).
+These are the "Trust Anchor" and "End Entity" variants.
+The latter specifies the End Entity directly, i.e. the certificate involved is that of the server
+(and if only DANE-EE is used then it should be the sole one transmitted during the TLS handshake);
+this is appropriate for a single system, using a self-signed certificate.

 DANE-TA usage is effectively declaring a specific CA to be used; this might be a private CA or a public,
 DANE-TA usage is effectively declaring a specific CA to be used; this might be a private CA or a public,

-well-known one.  A private CA at simplest is just a self-signed certificate which is used to sign
-cerver certificates, but running one securely does require careful arrangement.  If a private CA is used
-then either all clients must be primed with it, or (probably simpler) the server TLS handshake must transmit
-the entire certificate chain from CA to server-certificate.  If a public CA is used then all clients must be primed with it
-(losing one advantage of DANE) - but the attack surface is reduced from all public CAs to that single CA.
+well-known one.
+A private CA at simplest is just a self-signed certificate (with certain
+attributes) which is used to sign server certificates, but running one securely
+does require careful arrangement.
+With DANE-TA, as implemented in Exim and commonly in other MTAs,
+the server TLS handshake must transmit the entire certificate chain from CA to server-certificate.

 DANE-TA is commonly used for several services and/or servers, each having a TLSA query-domain CNAME record,
 all of which point to a single TLSA record.
 DANE-TA is commonly used for several services and/or servers, each having a TLSA query-domain CNAME record,
 all of which point to a single TLSA record.

+DANE-TA and DANE-EE can both be used together.

 
 

-Another approach which should be seriously considered is to use DANE with a certificate
-from a public CA, because of another technology, "MTA-STS", described below.
+.new
+Our recommendation is to use DANE with a certificate from a public CA,
+because this enables a variety of strategies for remote clients to verify
+your certificate.
+You can then publish information both via DANE and another technology,
+"MTA-STS", described below.
+
+When you use DANE-TA to publish trust anchor information, you ask entities
+outside your administrative control to trust the Certificate Authority for
+connections to you.
+If using a private CA then you should expect others to still apply the
+technical criteria they'd use for a public CA to your certificates.
+In particular, you should probably try to follow current best practices for CA
+operation around hash algorithms and key sizes.
+Do not expect other organizations to lower their security expectations just
+because a particular profile might be reasonable for your own internal use.
+
+When this text was last updated, this in practice means to avoid use of SHA-1
+and MD5; if using RSA to use key sizes of at least 2048 bits (and no larger
+than 4096, for interoperability); to use keyUsage fields correctly; to use
+random serial numbers.
+The list of requirements is subject to change as best practices evolve.
+If you're not already using a private CA, or it doesn't meet these
+requirements, then we encourage you to avoid all these issues and use a public
+CA such as &url(https://letsencrypt.org/,Let's Encrypt) instead.
+.wen

 
 The TLSA record should have a Selector field of SPKI(1) and a Matching Type field of SHA2-512(2).
 
 
 The TLSA record should have a Selector field of SPKI(1) and a Matching Type field of SHA2-512(2).
 


@@ -28185,6 +28349,16 @@ are workable for 4th-field hashes.
 
 For use with the DANE-TA model, server certificates must have a correct name (SubjectName or SubjectAltName).
 
 
 For use with the DANE-TA model, server certificates must have a correct name (SubjectName or SubjectAltName).
 

+.new
+The Certificate issued by the CA published in the DANE-TA model should be
+issued using a strong hash algorithm.
+Exim, and importantly various other MTAs sending to you, will not
+re-enable hash algorithms which have been disabled by default in TLS
+libraries.
+This means no MD5 and no SHA-1.  SHA2-256 is the minimum for reliable
+interoperability (and probably the maximum too, in 2018).
+.wen
+

 The use of OCSP-stapling should be considered, allowing for fast revocation of certificates (which would otherwise
 be limited by the DNS TTL on the TLSA records).  However, this is likely to only be usable with DANE-TA.  NOTE: the
 default of requesting OCSP for all hosts is modified iff DANE is in use, to:
 The use of OCSP-stapling should be considered, allowing for fast revocation of certificates (which would otherwise
 be limited by the DNS TTL on the TLSA records).  However, this is likely to only be usable with DANE-TA.  NOTE: the
 default of requesting OCSP for all hosts is modified iff DANE is in use, to:


@@ -28267,8 +28441,8 @@ MTA-STS to let those clients who do use that protocol derive trust
 information.
 
 The MTA-STS design requires a certificate from a public Certificate Authority
 information.
 
 The MTA-STS design requires a certificate from a public Certificate Authority

-which is recognized by clients sending to you.  That selection is outside your
-control.
+which is recognized by clients sending to you.
+That selection of which CAs are trusted by others is outside your control.

 
 The most interoperable course of action is probably to use
 &url(https://letsencrypt.org/,Let's Encrypt), with automated certificate
 
 The most interoperable course of action is probably to use
 &url(https://letsencrypt.org/,Let's Encrypt), with automated certificate


@@ -28277,7 +28451,6 @@ records for DANE clients (such as Exim and Postfix) and to publish anchor
 information for MTA-STS as well.  This is what is done for the &'exim.org'&
 domain itself (with caveats around occasionally broken MTA-STS because of
 incompatible specification changes prior to reaching RFC status).
 information for MTA-STS as well.  This is what is done for the &'exim.org'&
 domain itself (with caveats around occasionally broken MTA-STS because of
 incompatible specification changes prior to reaching RFC status).

-.wen

 
 
 
 
 
 


@@ -29900,9 +30073,10 @@ warn   hosts           = +internal_hosts
 warn   message         = Remove internal headers
        remove_header   = $acl_c_ihdrs
 .endd
 warn   message         = Remove internal headers
        remove_header   = $acl_c_ihdrs
 .endd

-Removed header lines are accumulated during the MAIL, RCPT, and predata ACLs.
-They are removed from the message before processing the DATA and MIME ACLs.
-There is no harm in attempting to remove the same header twice nor is removing
+Header names for removal are accumulated during the MAIL, RCPT, and predata ACLs.
+Matching header lines are removed from the message before processing the DATA and MIME ACLs.
+If multiple header lines match, all are removed.
+There is no harm in attempting to remove the same header twice nor in removing

 a non-existent header. Further header lines to be removed may be accumulated
 during the DATA and MIME ACLs, after which they are removed from the message,
 if present. In the case of non-SMTP messages, headers to be removed are
 a non-existent header. Further header lines to be removed may be accumulated
 during the DATA and MIME ACLs, after which they are removed from the message,
 if present. In the case of non-SMTP messages, headers to be removed are


@@ -30434,6 +30608,10 @@ connection (assuming long-enough TTL).
 Exim does not share information between multiple incoming
 connections (but your local name server cache should be active).
 
 Exim does not share information between multiple incoming
 connections (but your local name server cache should be active).
 

+There are a number of DNS lists to choose from, some commercial, some free,
+or free for small deployments.  An overview can be found at
+&url(https://en.wikipedia.org/wiki/Comparison_of_DNS_blacklists).
+

 
 
 .section "Specifying the IP address for a DNS list lookup" "SECID201"
 
 
 .section "Specifying the IP address for a DNS list lookup" "SECID201"


@@ -30455,8 +30633,7 @@ MX hosts or nameservers of an email sender address. For an example, see section
 .section "DNS lists keyed on domain names" "SECID202"
 .cindex "DNS list" "keyed by domain name"
 There are some lists that are keyed on domain names rather than inverted IP
 .section "DNS lists keyed on domain names" "SECID202"
 .cindex "DNS list" "keyed by domain name"
 There are some lists that are keyed on domain names rather than inverted IP

-addresses (see for example the &'domain based zones'& link at
-&url(http://www.rfc-ignorant.org/)). No reversing of components is used
+addresses.  No reversing of components is used

 with these lists. You can change the name that is looked up in a DNS list by
 listing it after the domain name, introduced by a slash. For example,
 .code
 with these lists. You can change the name that is looked up in a DNS list by
 listing it after the domain name, introduced by a slash. For example,
 .code


@@ -30790,7 +30967,7 @@ restrictions, to get the TXT record. As a byproduct of this, there is also
 a check that the IP being tested is indeed on the first list. The first
 domain is the one that is put in &$dnslist_domain$&. For example:
 .code
 a check that the IP being tested is indeed on the first list. The first
 domain is the one that is put in &$dnslist_domain$&. For example:
 .code

-reject message  = \
+deny message  = \

          rejected because $sender_host_address is blacklisted \
          at $dnslist_domain\n$dnslist_text
        dnslists = \
          rejected because $sender_host_address is blacklisted \
          at $dnslist_domain\n$dnslist_text
        dnslists = \


@@ -30808,7 +30985,7 @@ If you are interested in more than one merged list, the same list must be
 given several times, but because the results of the DNS lookups are cached,
 the DNS calls themselves are not repeated. For example:
 .code
 given several times, but because the results of the DNS lookups are cached,
 the DNS calls themselves are not repeated. For example:
 .code

-reject dnslists = \
+deny dnslists = \

          http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
          socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3 : \
          misc.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.4 : \
          http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
          socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3 : \
          misc.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.4 : \


@@ -31019,13 +31196,15 @@ rest of the ACL.
 
 The &%leaky%& (default) option means that the client's recorded rate is not
 updated if it is above the limit. The effect of this is that Exim measures the
 
 The &%leaky%& (default) option means that the client's recorded rate is not
 updated if it is above the limit. The effect of this is that Exim measures the

-client's average rate of successfully sent email, which cannot be greater than
-the maximum allowed. If the client is over the limit it may suffer some
-counter-measures (as specified in the ACL), but it will still be able to send
-email at the configured maximum rate, whatever the rate of its attempts. This
+client's average rate of successfully sent email,
+.new
+up to the given limit.
+This is appropriate if the countermeasure when the condition is true
+consists of refusing the message, and

 is generally the better choice if you have clients that retry automatically.
 is generally the better choice if you have clients that retry automatically.

-For example, it does not prevent a sender with an over-aggressive retry rate
-from getting any email through.
+If the action when true is anything more complex then this option is
+likely not what is wanted.
+.wen

 
 The &%strict%& option means that the client's recorded rate is always
 updated. The effect of this is that Exim measures the client's average rate
 
 The &%strict%& option means that the client's recorded rate is always
 updated. The effect of this is that Exim measures the client's average rate


@@ -31196,6 +31375,15 @@ connection, HELO, or MAIL).
 The main use of these variables is expected to be to distinguish between
 rejections of MAIL and rejections of RCPT in callouts.
 
 The main use of these variables is expected to be to distinguish between
 rejections of MAIL and rejections of RCPT in callouts.
 

+.new
+The above variables may also be set after a &*successful*&
+address verification to:
+
+.ilist
+&%random%&: A random local-part callout succeeded
+.endlist
+.wen
+

 
 
 
 
 
 


@@ -31928,13 +32116,11 @@ A list of options may follow. These options are interpreted on the
 Exim's side of the malware scanner, or are given on separate lines to
 the daemon as options before the main scan command.
 
 Exim's side of the malware scanner, or are given on separate lines to
 the daemon as options before the main scan command.
 

-.new

 .cindex &`pass_unscanned`& "avast"
 If &`pass_unscanned`&
 is set, any files the Avast scanner can't scan (e.g.
 decompression bombs, or invalid archives) are considered clean. Use with
 care.
 .cindex &`pass_unscanned`& "avast"
 If &`pass_unscanned`&
 is set, any files the Avast scanner can't scan (e.g.
 decompression bombs, or invalid archives) are considered clean. Use with
 care.

-.wen

 
 For example:
 .code
 
 For example:
 .code


@@ -31963,7 +32149,7 @@ written.  The usual &`defer_ok`& option is available.
 .vitem &%aveserver%&
 .cindex "virus scanners" "Kaspersky"
 This is the scanner daemon of Kaspersky Version 5. You can get a trial version
 .vitem &%aveserver%&
 .cindex "virus scanners" "Kaspersky"
 This is the scanner daemon of Kaspersky Version 5. You can get a trial version

-at &url(http://www.kaspersky.com). This scanner type takes one option,
+at &url(https://www.kaspersky.com/). This scanner type takes one option,

 which is the path to the daemon's UNIX socket. The default is shown in this
 example:
 .code
 which is the path to the daemon's UNIX socket. The default is shown in this
 example:
 .code


@@ -31974,7 +32160,7 @@ av_scanner = aveserver:/var/run/aveserver
 .vitem &%clamd%&
 .cindex "virus scanners" "clamd"
 This daemon-type scanner is GPL and free. You can get it at
 .vitem &%clamd%&
 .cindex "virus scanners" "clamd"
 This daemon-type scanner is GPL and free. You can get it at

-&url(http://www.clamav.net/). Some older versions of clamd do not seem to
+&url(https://www.clamav.net/). Some older versions of clamd do not seem to

 unpack MIME containers, so it used to be recommended to unpack MIME attachments
 in the MIME ACL. This is no longer believed to be necessary.
 
 unpack MIME containers, so it used to be recommended to unpack MIME attachments
 in the MIME ACL. This is no longer believed to be necessary.
 


@@ -32068,7 +32254,7 @@ av_scanner = cmdline:\
 .endd
 .vitem &%drweb%&
 .cindex "virus scanners" "DrWeb"
 .endd
 .vitem &%drweb%&
 .cindex "virus scanners" "DrWeb"

-The DrWeb daemon scanner (&url(http://www.sald.com/)) interface
+The DrWeb daemon scanner (&url(https://www.sald.ru/)) interface

 takes one option,
 either a full path to a UNIX socket,
 or host and port specifiers separated by white space.
 takes one option,
 either a full path to a UNIX socket,
 or host and port specifiers separated by white space.


@@ -32105,7 +32291,7 @@ If you omit the argument, the default values show above are used.
 
 .vitem &%fsecure%&
 .cindex "virus scanners" "F-Secure"
 
 .vitem &%fsecure%&
 .cindex "virus scanners" "F-Secure"

-The F-Secure daemon scanner (&url(http://www.f-secure.com)) takes one
+The F-Secure daemon scanner (&url(https://www.f-secure.com/)) takes one

 argument which is the path to a UNIX socket. For example:
 .code
 av_scanner = fsecure:/path/to/.fsav
 argument which is the path to a UNIX socket. For example:
 .code
 av_scanner = fsecure:/path/to/.fsav


@@ -32126,9 +32312,13 @@ The default path is &_/var/run/AvpCtl_&.
 
 .vitem &%mksd%&
 .cindex "virus scanners" "mksd"
 
 .vitem &%mksd%&
 .cindex "virus scanners" "mksd"

-This is a daemon type scanner that is aimed mainly at Polish users, though some
-parts of documentation are now available in English. You can get it at
-&url(http://linux.mks.com.pl/). The only option for this scanner type is
+This was a daemon type scanner that is aimed mainly at Polish users,
+though some documentation was available in English.
+The history can be shown at &url(https://en.wikipedia.org/wiki/Mks_vir)
+and this appears to be a candidate for removal from Exim, unless
+we are informed of other virus scanners which use the same protocol
+to integrate.
+The only option for this scanner type is

 the maximum number of processes used simultaneously to scan the attachments,
 provided that mksd has
 been run with at least the same number of child processes. For example:
 the maximum number of processes used simultaneously to scan the attachments,
 provided that mksd has
 been run with at least the same number of child processes. For example:


@@ -32160,7 +32350,7 @@ specify an empty element to get this.
 .vitem &%sophie%&
 .cindex "virus scanners" "Sophos and Sophie"
 Sophie is a daemon that uses Sophos' &%libsavi%& library to scan for viruses.
 .vitem &%sophie%&
 .cindex "virus scanners" "Sophos and Sophie"
 Sophie is a daemon that uses Sophos' &%libsavi%& library to scan for viruses.

-You can get Sophie at &url(http://www.clanfield.info/sophie/). The only option
+You can get Sophie at &url(http://sophie.sourceforge.net/). The only option

 for this scanner type is the path to the UNIX socket that Sophie uses for
 client communication. For example:
 .code
 for this scanner type is the path to the UNIX socket that Sophie uses for
 client communication. For example:
 .code


@@ -32264,7 +32454,7 @@ Support is also provided for Rspamd.
 
 For more information about installation and configuration of SpamAssassin or
 Rspamd refer to their respective websites at
 
 For more information about installation and configuration of SpamAssassin or
 Rspamd refer to their respective websites at

-&url(http://spamassassin.apache.org) and &url(http://www.rspamd.com)
+&url(https://spamassassin.apache.org/) and &url(https://www.rspamd.com/)

 
 SpamAssassin can be installed with CPAN by running:
 .code
 
 SpamAssassin can be installed with CPAN by running:
 .code


@@ -32788,10 +32978,15 @@ code. The incident is logged on the main and reject logs.
 .section "Building Exim to use a local scan function" "SECID207"
 .cindex "&[local_scan()]& function" "building Exim to use"
 To make use of the local scan function feature, you must tell Exim where your
 .section "Building Exim to use a local scan function" "SECID207"
 .cindex "&[local_scan()]& function" "building Exim to use"
 To make use of the local scan function feature, you must tell Exim where your

-function is before building Exim, by setting LOCAL_SCAN_SOURCE in your
+function is before building Exim, by setting
+.new
+both HAVE_LOCAL_SCAN and
+.wen
+LOCAL_SCAN_SOURCE in your

 &_Local/Makefile_&. A recommended place to put it is in the &_Local_&
 directory, so you might set
 .code
 &_Local/Makefile_&. A recommended place to put it is in the &_Local_&
 directory, so you might set
 .code

+HAVE_LOCAL_SCAN=yes

 LOCAL_SCAN_SOURCE=Local/local_scan.c
 .endd
 for example. The function must be called &[local_scan()]&. It is called by
 LOCAL_SCAN_SOURCE=Local/local_scan.c
 .endd
 for example. The function must be called &[local_scan()]&. It is called by


@@ -35448,7 +35643,7 @@ the address, giving a suitable error message.
 .cindex "VERP"
 .cindex "Variable Envelope Return Paths"
 .cindex "envelope sender"
 .cindex "VERP"
 .cindex "Variable Envelope Return Paths"
 .cindex "envelope sender"

-Variable Envelope Return Paths &-- see &url(http://cr.yp.to/proto/verp.txt) &--
+Variable Envelope Return Paths &-- see &url(https://cr.yp.to/proto/verp.txt) &--

 are a way of helping mailing list administrators discover which subscription
 address is the cause of a particular delivery failure. The idea is to encode
 the original recipient address in the outgoing envelope sender address, so that
 are a way of helping mailing list administrators discover which subscription
 address is the cause of a particular delivery failure. The idea is to encode
 the original recipient address in the outgoing envelope sender address, so that


@@ -36438,8 +36633,9 @@ the following table:
 &`F   `&        sender address (on delivery lines)
 &`H   `&        host name and IP address
 &`I   `&        local interface used
 &`F   `&        sender address (on delivery lines)
 &`H   `&        host name and IP address
 &`I   `&        local interface used

-&`K   `&        CHUNKING extension used

 &`id  `&        message id for incoming message
 &`id  `&        message id for incoming message

+&`K   `&        CHUNKING extension used
+&`L   `&        on &`<=`& and &`=>`& lines: PIPELINING extension used

 &`M8S `&        8BITMIME status for incoming message
 &`P   `&        on &`<=`& lines: protocol used
 &`    `&        on &`=>`& and &`**`& lines: return path
 &`M8S `&        8BITMIME status for incoming message
 &`P   `&        on &`<=`& lines: protocol used
 &`    `&        on &`=>`& and &`**`& lines: return path


@@ -36503,11 +36699,9 @@ A delivery set up by a router configured with
 failed. The delivery was discarded.
 .endlist olist
 .next
 failed. The delivery was discarded.
 .endlist olist
 .next

-.new

 .cindex DKIM "log line"
 &'DKIM: d='&&~&~Verbose results of a DKIM verification attempt, if enabled for
 logging and the message has a DKIM signature header.
 .cindex DKIM "log line"
 &'DKIM: d='&&~&~Verbose results of a DKIM verification attempt, if enabled for
 logging and the message has a DKIM signature header.

-.wen

 .endlist ilist
 
 
 .endlist ilist
 
 


@@ -36552,6 +36746,7 @@ selection marked by asterisks:
 &` queue_time                 `&  time on queue for one recipient
 &` queue_time_overall         `&  time on queue for whole message
 &` pid                        `&  Exim process id
 &` queue_time                 `&  time on queue for one recipient
 &` queue_time_overall         `&  time on queue for whole message
 &` pid                        `&  Exim process id

+&` pipelining                 `&  PIPELINING use, on <= and => lines

 &` proxy                      `&  proxy address on <= and => lines
 &` receive_time               `&  time taken to receive message
 &` received_recipients        `&  recipients on <= lines
 &` proxy                      `&  proxy address on <= and => lines
 &` receive_time               `&  time taken to receive message
 &` received_recipients        `&  recipients on <= lines


@@ -36644,7 +36839,6 @@ precision, eg. &`DT=0.304s`&.
 &%delivery_size%&: For each delivery, the size of message delivered is added to
 the &"=>"& line, tagged with S=.
 .next
 &%delivery_size%&: For each delivery, the size of message delivered is added to
 the &"=>"& line, tagged with S=.
 .next

-.new

 .cindex log "DKIM verification"
 .cindex DKIM "verification logging"
 &%dkim%&: For message acceptance log lines, when an DKIM signature in the header
 .cindex log "DKIM verification"
 .cindex DKIM "verification logging"
 &%dkim%&: For message acceptance log lines, when an DKIM signature in the header


@@ -36653,7 +36847,6 @@ 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.

-.wen

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


@@ -36756,6 +36949,15 @@ local port is a random ephemeral port.
 &%pid%&: The current process id is added to every log line, in square brackets,
 immediately after the time and date.
 .next
 &%pid%&: The current process id is added to every log line, in square brackets,
 immediately after the time and date.
 .next

+.new
+.cindex log pipelining
+.cindex pipelining "logging outgoing"
+&%pipelining%&: A field is added to delivery and accept
+log lines when the ESMTP PIPELINING extension was used.
+The field is a single "L".
+On accept lines, where PIPELINING was offered but not used by the client,
+the field has a minus appended.
+.next

 .cindex "log" "queue run"
 .cindex "queue runner" "logging"
 &%queue_run%&: The start and end of every queue run are logged.
 .cindex "log" "queue run"
 .cindex "queue runner" "logging"
 &%queue_run%&: The start and end of every queue run are logged.


@@ -36775,14 +36977,12 @@ precision, eg. &`QT=1.578s`&.
 the local host is logged as QT=<&'time'&> on &"Completed"& lines, for
 example, &`QT=3m45s`&. The clock starts when Exim starts to receive the
 message, so it includes reception time as well as the total delivery time.
 the local host is logged as QT=<&'time'&> on &"Completed"& lines, for
 example, &`QT=3m45s`&. The clock starts when Exim starts to receive the
 message, so it includes reception time as well as the total delivery time.

-.new

 .next
 .cindex "log" "receive duration"
 &%receive_time%&: For each message, the amount of real time it has taken to
 perform the reception is logged as RT=<&'time'&>, for example, &`RT=1s`&.
 If millisecond logging is enabled, short times will be shown with greater
 precision, eg. &`RT=0.204s`&.
 .next
 .cindex "log" "receive duration"
 &%receive_time%&: For each message, the amount of real time it has taken to
 perform the reception is logged as RT=<&'time'&>, for example, &`RT=1s`&.
 If millisecond logging is enabled, short times will be shown with greater
 precision, eg. &`RT=0.204s`&.

-.wen

 .next
 .cindex "log" "recipients"
 &%received_recipients%&: The recipients of a message are listed in the main log
 .next
 .cindex "log" "recipients"
 &%received_recipients%&: The recipients of a message are listed in the main log


@@ -36940,10 +37140,8 @@ unchanged, or whether they should be rendered as escape sequences.
 &%tls_certificate_verified%&: An extra item is added to <= and => log lines
 when TLS is in use. The item is &`CV=yes`& if the peer's certificate was
 verified
 &%tls_certificate_verified%&: An extra item is added to <= and => log lines
 when TLS is in use. The item is &`CV=yes`& if the peer's certificate was
 verified

-.new

 using a CA trust anchor,
 &`CA=dane`& if using a DNS trust anchor,
 using a CA trust anchor,
 &`CA=dane`& if using a DNS trust anchor,

-.wen

 and &`CV=no`& if not.
 .next
 .cindex "log" "TLS cipher"
 and &`CV=no`& if not.
 .next
 .cindex "log" "TLS cipher"


@@ -37023,7 +37221,7 @@ the next chapter. The utilities described here are:
 
 Another utility that might be of use to sites with many MTAs is Tom Kistner's
 &'exilog'&. It provides log visualizations across multiple Exim servers. See
 
 Another utility that might be of use to sites with many MTAs is Tom Kistner's
 &'exilog'&. It provides log visualizations across multiple Exim servers. See

-&url(http://duncanthrax.net/exilog/) for details.
+&url(https://duncanthrax.net/exilog/) for details.

 
 
 
 
 
 


@@ -37291,8 +37489,8 @@ assuming you have used the name &"exim"& for the Exim user. You can run
 .cindex "&'eximstats'&"
 A Perl script called &'eximstats'& is provided for extracting statistical
 information from log files. The output is either plain text, or HTML.
 .cindex "&'eximstats'&"
 A Perl script called &'eximstats'& is provided for extracting statistical
 information from log files. The output is either plain text, or HTML.

-Exim log files are also supported by the &'Lire'& system produced by the
-LogReport Foundation &url(http://www.logreport.org).
+. --- 2018-09-07: LogReport's Lire appears to be dead; website is a Yahoo Japan
+. --- 404 error and everything else points to that.

 
 The &'eximstats'& script has been hacked about quite a bit over time. The
 latest version is the result of some extensive revision by Steve Campbell. A
 
 The &'eximstats'& script has been hacked about quite a bit over time. The
 latest version is the result of some extensive revision by Steve Campbell. A


@@ -38579,6 +38777,12 @@ two files contains the final component of its own name as its first line. This
 is insurance against disk crashes where the directory is lost but the files
 themselves are recoverable.
 
 is insurance against disk crashes where the directory is lost but the files
 themselves are recoverable.
 

+.new
+The file formats may be changed, or new formats added, at any release.
+Spool files are not intended as an interface to other programs
+and should not be used as such.
+.wen
+

 Some people are tempted into editing -D files in order to modify messages. You
 need to be extremely careful if you do this; it is not recommended and you are
 on your own if you do it. Here are some of the pitfalls:
 Some people are tempted into editing -D files in order to modify messages. You
 need to be extremely careful if you do this; it is not recommended and you are
 on your own if you do it. Here are some of the pitfalls:


@@ -38916,11 +39120,9 @@ linked to a domain which that entity controls.  It permits reputation to
 be tracked on a per-domain basis, rather than merely upon source IP address.
 DKIM is documented in RFC 6376.
 
 be tracked on a per-domain basis, rather than merely upon source IP address.
 DKIM is documented in RFC 6376.
 

-.new

 As DKIM relies on the message being unchanged in transit, messages handled
 by a mailing-list (which traditionally adds to the message) will not match
 any original DKIM signature.
 As DKIM relies on the message being unchanged in transit, messages handled
 by a mailing-list (which traditionally adds to the message) will not match
 any original DKIM signature.

-.wen

 
 DKIM support is compiled into Exim by default if TLS support is present.
 It can be disabled by setting DISABLE_DKIM=yes in &_Local/Makefile_&.
 
 DKIM support is compiled into Exim by default if TLS support is present.
 It can be disabled by setting DISABLE_DKIM=yes in &_Local/Makefile_&.


@@ -38941,7 +39143,6 @@ In typical Exim style, the verification implementation does not include any
 default "policy". Instead it enables you to build your own policy using
 Exim's standard controls.
 
 default "policy". Instead it enables you to build your own policy using
 Exim's standard controls.
 

-.new

 Please note that verification of DKIM signatures in incoming mail is turned
 on by default for logging (in the <= line) purposes.
 
 Please note that verification of DKIM signatures in incoming mail is turned
 on by default for logging (in the <= line) purposes.
 


@@ -38955,7 +39156,6 @@ signature status. Here is an example (with line-breaks added for clarity):
     c=relaxed/relaxed a=rsa-sha1
     i=@facebookmail.com t=1252484542 [verification succeeded]
 .endd
     c=relaxed/relaxed a=rsa-sha1
     i=@facebookmail.com t=1252484542 [verification succeeded]
 .endd

-.wen

 
 You might want to turn off DKIM verification processing entirely for internal
 or relay mail sources. To do that, set the &%dkim_disable_verify%& ACL
 
 You might want to turn off DKIM verification processing entirely for internal
 or relay mail sources. To do that, set the &%dkim_disable_verify%& ACL


@@ -38967,7 +39167,6 @@ senders).
 .section "Signing outgoing messages" "SECDKIMSIGN"
 .cindex "DKIM" "signing"
 
 .section "Signing outgoing messages" "SECDKIMSIGN"
 .cindex "DKIM" "signing"
 

-.new

 For signing to be usable you must have published a DKIM record in DNS.
 Note that RFC 8301 says:
 .code
 For signing to be usable you must have published a DKIM record in DNS.
 Note that RFC 8301 says:
 .code


@@ -38982,7 +39181,6 @@ in the DNS record is different between RSA and EC keys;
 for the former it is the base64 of the ASN.1 for the RSA public key
 (equivalent to the private-key .pem with the header/trailer stripped)
 but for EC keys it is the base64 of the pure key; no ASN.1 wrapping.
 for the former it is the base64 of the ASN.1 for the RSA public key
 (equivalent to the private-key .pem with the header/trailer stripped)
 but for EC keys it is the base64 of the pure key; no ASN.1 wrapping.

-.wen

 
 Signing is enabled by setting private options on the SMTP transport.
 These options take (expandable) strings as arguments.
 
 Signing is enabled by setting private options on the SMTP transport.
 These options take (expandable) strings as arguments.


@@ -39011,11 +39209,9 @@ You can use the &%$dkim_domain%& and
 The result can either
 .ilist
 be a valid RSA private key in ASCII armor (.pem file), including line breaks
 The result can either
 .ilist
 be a valid RSA private key in ASCII armor (.pem file), including line breaks

-.new

 .next
 with GnuTLS 3.6.0 or OpenSSL 1.1.1 or later,
 be a valid Ed25519 private key (same format as above)
 .next
 with GnuTLS 3.6.0 or OpenSSL 1.1.1 or later,
 be a valid Ed25519 private key (same format as above)

-.wen

 .next
 start with a slash, in which case it is treated as a file that contains
 the private key
 .next
 start with a slash, in which case it is treated as a file that contains
 the private key


@@ -39025,7 +39221,6 @@ be signed. This case will not result in an error, even if &%dkim_strict%&
 is set.
 .endlist
 
 is set.
 .endlist
 

-.new

 To generate keys under OpenSSL:
 .code
 openssl genrsa -out dkim_rsa.private 2048
 To generate keys under OpenSSL:
 .code
 openssl genrsa -out dkim_rsa.private 2048


@@ -39071,11 +39266,9 @@ certtool --load_privkey=dkim_ed25519.private --pubkey_info --outder | tail -c +1
 Note that the format
 of Ed25519 keys in DNS has not yet been decided; this release supports
 both of the leading candidates at this time, a future release will
 Note that the format
 of Ed25519 keys in DNS has not yet been decided; this release supports
 both of the leading candidates at this time, a future release will

-probably drop support for whichever proposal loses
-.wen
+probably drop support for whichever proposal loses.

 
 .option dkim_hash smtp string&!! sha256
 
 .option dkim_hash smtp string&!! sha256

-.new

 Can be set to any one of the supported hash methods, which are:
 .ilist
 &`sha1`& &-- should not be used, is old and insecure
 Can be set to any one of the supported hash methods, which are:
 .ilist
 &`sha1`& &-- should not be used, is old and insecure


@@ -39084,14 +39277,11 @@ Can be set to any one of the supported hash methods, which are:
 .next
 &`sha512`& &-- possibly more secure but less well supported
 .endlist
 .next
 &`sha512`& &-- possibly more secure but less well supported
 .endlist

-.wen

 
 

-.new

 Note that RFC 8301 says:
 .code
 rsa-sha1 MUST NOT be used for signing or verifying.
 .endd
 Note that RFC 8301 says:
 .code
 rsa-sha1 MUST NOT be used for signing or verifying.
 .endd

-.wen

 
 .option dkim_identity smtp string&!! unset
 If set after expansion, the value is used to set an "i=" tag in
 
 .option dkim_identity smtp string&!! unset
 If set after expansion, the value is used to set an "i=" tag in


@@ -39104,7 +39294,7 @@ tag value.  Note that Exim does not check the value.
 This option sets the canonicalization method used when signing a message.
 The DKIM RFC currently supports two methods: "simple" and "relaxed".
 The option defaults to "relaxed" when unset. Note: the current implementation
 This option sets the canonicalization method used when signing a message.
 The DKIM RFC currently supports two methods: "simple" and "relaxed".
 The option defaults to "relaxed" when unset. Note: the current implementation

-only supports using the same canonicalization method for both headers and body.
+only supports signing with the same canonicalization method for both headers and body.

 
 .option dkim_strict smtp string&!! unset
 This  option  defines  how  Exim  behaves  when  signing a message that
 
 .option dkim_strict smtp string&!! unset
 This  option  defines  how  Exim  behaves  when  signing a message that


@@ -39134,28 +39324,44 @@ If a '+' prefix if used, all headers that are present with this name
 will be signed, and one signature added for a missing header with the
 name will be appended.
 
 will be signed, and one signature added for a missing header with the
 name will be appended.
 

+.new
+.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.
+
+RFC 6376 lists these tags as RECOMMENDED.
+.wen
+

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

-Verification of DKIM signatures in SMTP incoming email is implemented via the
-&%acl_smtp_dkim%& ACL. By default, this ACL is called once for each
+.new
+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 authentication "expansion item"
+Performing verification sets up information used by the
+&$authresults$& expansion item.
+.wen
+
+.new The results of that verification are then made available to the
+&%acl_smtp_dkim%& ACL, &new(which can examine and modify them).
+By default, this ACL is called once for each

 syntactically(!) correct signature in the incoming message.
 A missing ACL definition defaults to accept.
 If any ACL call does not accept, the message is not accepted.
 If a cutthrough delivery was in progress for the message, that is
 summarily dropped (having wasted the transmission effort).
 
 syntactically(!) correct signature in the incoming message.
 A missing ACL definition defaults to accept.
 If any ACL call does not accept, the message is not accepted.
 If a cutthrough delivery was in progress for the message, that is
 summarily dropped (having wasted the transmission effort).
 

-To evaluate the signature in the ACL a large number of expansion variables
+To evaluate the &new(verification result) in the ACL
+a large number of expansion variables

 containing the signature status and its details are set up during the
 runtime of the ACL.
 
 containing the signature status and its details are set up during the
 runtime of the ACL.
 

-.new
-.cindex authentication "expansion item"
-Performing verification sets up information used by the
-&$authresults$& expansion item.
-.wen
-

 Calling the ACL only for existing signatures is not sufficient to build
 more advanced policies. For that reason, the global option
 &%dkim_verify_signers%&, and a global expansion variable
 Calling the ACL only for existing signatures is not sufficient to build
 more advanced policies. For that reason, the global option
 &%dkim_verify_signers%&, and a global expansion variable


@@ -39230,8 +39436,10 @@ 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
 

-After all the DKIM ACL runs have completed, the value becomes a
+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.
 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
 
 .vitem &%$dkim_verify_reason%&
 A string giving a little bit more detail when &%$dkim_verify_status%& is either


@@ -39270,14 +39478,11 @@ The key record selector string.
 
 .vitem &%$dkim_algo%&
 The algorithm used. One of 'rsa-sha1' or 'rsa-sha256'.
 
 .vitem &%$dkim_algo%&
 The algorithm used. One of 'rsa-sha1' or 'rsa-sha256'.

-.new

 If running under GnuTLS 3.6.0 or OpenSSL 1.1.1 or later,
 may also be 'ed25519-sha256'.
 The "_CRYPTO_SIGN_ED25519" macro will be defined if support is present
 for EC keys.
 If running under GnuTLS 3.6.0 or OpenSSL 1.1.1 or later,
 may also be 'ed25519-sha256'.
 The "_CRYPTO_SIGN_ED25519" macro will be defined if support is present
 for EC keys.

-.wen

 
 

-.new

 Note that RFC 8301 says:
 .code
 rsa-sha1 MUST NOT be used for signing or verifying.
 Note that RFC 8301 says:
 .code
 rsa-sha1 MUST NOT be used for signing or verifying.


@@ -39288,7 +39493,6 @@ algorithms (currently, rsa-sha1) have permanently failed evaluation
 
 To enforce this you must have a DKIM ACL which checks this variable
 and overwrites the &$dkim_verify_status$& variable as discussed above.
 
 To enforce this you must have a DKIM ACL which checks this variable
 and overwrites the &$dkim_verify_status$& variable as discussed above.

-.wen

 
 .vitem &%$dkim_canon_body%&
 The body canonicalization method. One of 'relaxed' or 'simple'.
 
 .vitem &%$dkim_canon_body%&
 The body canonicalization method. One of 'relaxed' or 'simple'.


@@ -39307,6 +39511,12 @@ strict enforcement should code the check explicitly.
 The number of signed body bytes. If zero ("0"), the body is unsigned. If no
 limit was set by the signer, "9999999999999" is returned. This makes sure
 that this variable always expands to an integer value.
 The number of signed body bytes. If zero ("0"), the body is unsigned. If no
 limit was set by the signer, "9999999999999" is returned. This makes sure
 that this variable always expands to an integer value.

+.new
+&*Note:*& The presence of the signature tag specifying a signing body length
+is one possible route to spoofing of valid DKIM signatures.
+A paranoid implementation might wish to regard signature where this variable
+shows less than the "no limit" return as being invalid.
+.wen

 
 .vitem &%$dkim_created%&
 UNIX timestamp reflecting the date and time when the signature was created.
 
 .vitem &%$dkim_created%&
 UNIX timestamp reflecting the date and time when the signature was created.


@@ -39317,9 +39527,7 @@ UNIX timestamp reflecting the date and time when the signer wants the
 signature to be treated as "expired". When this was not specified by the
 signer, "9999999999999" is returned. This makes it possible to do useful
 integer size comparisons against this value.
 signature to be treated as "expired". When this was not specified by the
 signer, "9999999999999" is returned. This makes it possible to do useful
 integer size comparisons against this value.

-.new

 Note that Exim does not check this value.
 Note that Exim does not check this value.

-.wen

 
 .vitem &%$dkim_headernames%&
 A colon-separated list of names of headers included in the signature.
 
 .vitem &%$dkim_headernames%&
 A colon-separated list of names of headers included in the signature.


@@ -39344,7 +39552,6 @@ Notes from the key record (tag n=).
 .vitem &%$dkim_key_length%&
 Number of bits in the key.
 
 .vitem &%$dkim_key_length%&
 Number of bits in the key.
 

-.new

 Note that RFC 8301 says:
 .code
 Verifiers MUST NOT consider signatures using RSA keys of
 Note that RFC 8301 says:
 .code
 Verifiers MUST NOT consider signatures using RSA keys of


@@ -39354,7 +39561,6 @@ less than 1024 bits as valid signatures.
 To enforce this you must have a DKIM ACL which checks this variable
 and overwrites the &$dkim_verify_status$& variable as discussed above.
 As EC keys are much smaller, the check should only do this for RSA keys.
 To enforce this you must have a DKIM ACL which checks this variable
 and overwrites the &$dkim_verify_status$& variable as discussed above.
 As EC keys are much smaller, the check should only do this for RSA keys.

-.wen

 
 .endlist
 
 
 .endlist
 


@@ -39398,29 +39604,27 @@ for more information of what they mean.
 
 
 
 
 
 

-.new

 .section "SPF (Sender Policy Framework)" SECSPF
 .cindex SPF verification
 
 SPF is a mechanism whereby a domain may assert which IP addresses may transmit
 messages with its domain in the envelope from, documented by RFC 7208.
 For more information on SPF see &url(http://www.openspf.org).
 .section "SPF (Sender Policy Framework)" SECSPF
 .cindex SPF verification
 
 SPF is a mechanism whereby a domain may assert which IP addresses may transmit
 messages with its domain in the envelope from, documented by RFC 7208.
 For more information on SPF see &url(http://www.openspf.org).

+. --- 2018-09-07: still not https

 
 Messages sent by a system not authorised will fail checking of such assertions.
 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
 
 Messages sent by a system not authorised will fail checking of such assertions.
 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(http://www.libspf2.org/).
+&url(https://www.libspf2.org/).

 There is no Exim involvement in the transmission of messages;
 publishing certain DNS records is all that is required.
 
 For verification, an ACL condition and an expansion lookup are provided.
 There is no Exim involvement in the transmission of messages;
 publishing certain DNS records is all that is required.
 
 For verification, an ACL condition and an expansion lookup are provided.

-.new

 .cindex authentication "expansion item"
 Performing verification sets up information used by the
 &$authresults$& expansion item.
 .cindex authentication "expansion item"
 Performing verification sets up information used by the
 &$authresults$& expansion item.

-.wen

 
 
 .cindex SPF "ACL condition"
 
 
 .cindex SPF "ACL condition"


@@ -39524,6 +39728,7 @@ SPF, but it is supported by the same framework that enables SPF
 capability.
 Refer to &url(http://www.openspf.org/FAQ/Best_guess_record)
 for a description of what it means.
 capability.
 Refer to &url(http://www.openspf.org/FAQ/Best_guess_record)
 for a description of what it means.

+. --- 2018-09-07: still not https:

 
 To access this feature, simply use the spf_guess condition in place
 of the spf one.  For example:
 
 To access this feature, simply use the spf_guess condition in place
 of the spf one.  For example:


@@ -39567,8 +39772,6 @@ The lookup will return the same result strings as can appear in
 Currently, only IPv4 addresses are supported.
 
 
 Currently, only IPv4 addresses are supported.
 
 

-. wen-for SPF section
-.wen

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


@@ -39594,10 +39797,8 @@ that uses &"Proxy Protocol"& to speak to it.
 To include this support, include &"SUPPORT_PROXY=yes"&
 in Local/Makefile.
 
 To include this support, include &"SUPPORT_PROXY=yes"&
 in Local/Makefile.
 

-It was built on specifications from:
-(&url(http://haproxy.1wt.eu/download/1.5/doc/proxy-protocol.txt)).
-That URL was revised in May 2014 to version 2 spec:
-(&url(http://git.1wt.eu/web?p=haproxy.git;a=commitdiff;h=afb768340c9d7e50d8e)).
+It was built on the HAProxy specification, found at
+&url(https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt).

 
 The purpose of this facility is so that an application load balancer,
 such as HAProxy, can sit in front of several Exim servers
 
 The purpose of this facility is so that an application load balancer,
 such as HAProxy, can sit in front of several Exim servers


@@ -39784,9 +39985,7 @@ ${utf8_localpart_from_alabel:str}
 
 .cindex utf8 "address downconversion"
 .cindex i18n "utf8 address downconversion"
 
 .cindex utf8 "address downconversion"
 .cindex i18n "utf8 address downconversion"

-.new

 The RCPT ACL
 The RCPT ACL

-.wen

 may use the following modifier:
 .display
 control = utf8_downconvert
 may use the following modifier:
 .display
 control = utf8_downconvert


@@ -39805,6 +40004,12 @@ If a value is appended it may be:
 If mua_wrapper is set, the utf8_downconvert control
 is initially set to -1.
 
 If mua_wrapper is set, the utf8_downconvert control
 is initially set to -1.
 

+.new
+The smtp transport has an option &%utf8_downconvert%&.
+If set it must expand to one of the three values described above,
+and it overrides any previously set value.
+.wen
+

 
 There is no explicit support for VRFY and EXPN.
 Configurations supporting these should inspect
 
 There is no explicit support for VRFY and EXPN.
 Configurations supporting these should inspect


@@ -39926,6 +40131,8 @@ with the event type:
 .display
 &`dane:fail            `& failure reason
 &`msg:delivery         `& smtp confirmation message
 .display
 &`dane:fail            `& failure reason
 &`msg:delivery         `& smtp confirmation message

+&`msg:fail:internal    `& failure reason
+&`msg:fail:delivery    `& smtp error message

 &`msg:rcpt:host:defer  `& error string
 &`msg:rcpt:defer       `& error string
 &`msg:host:defer       `& error string
 &`msg:rcpt:host:defer  `& error string
 &`msg:rcpt:defer       `& error string
 &`msg:host:defer       `& error string