DKIM: add builtin macro with default list of headers for signing

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

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index c9f841ad0d70aba943c27bfe21fc46cce0306a01..d030ee238ee8c49c5943429c76bd415ba488c398 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -1667,6 +1667,9 @@ Symbolic links to the sources are installed in this directory, which is where
 the actual building takes place. In most cases, Exim can discover the machine
 architecture and operating system for itself, but the defaults can be
 overridden if necessary.
 the actual building takes place. In most cases, Exim can discover the machine
 architecture and operating system for itself, but the defaults can be
 overridden if necessary.

+.cindex compiler requirements
+.cindex compiler version
+A C99-capable compiler will be required for the build.

 
 
 .section "PCRE library" "SECTpcre"
 
 
 .section "PCRE library" "SECTpcre"


@@ -4274,7 +4277,7 @@ or &%-bs%& is used. For &%-bh%&, the protocol is forced to one of the standard
 SMTP protocol names (see the description of &$received_protocol$& in section
 &<<SECTexpvar>>&). For &%-bs%&, the protocol is always &"local-"& followed by
 one of those same names. For &%-bS%& (batched SMTP) however, the protocol can
 SMTP protocol names (see the description of &$received_protocol$& in section
 &<<SECTexpvar>>&). For &%-bs%&, the protocol is always &"local-"& followed by
 one of those same names. For &%-bS%& (batched SMTP) however, the protocol can

-be set by &%-oMr%&.
+be set by &%-oMr%&. Repeated use of this option is not supported.

 
 .vitem &%-oMs%&&~<&'host&~name'&>
 .oindex "&%-oMs%&"
 
 .vitem &%-oMs%&&~<&'host&~name'&>
 .oindex "&%-oMs%&"


@@ -4374,6 +4377,7 @@ host name and its colon can be omitted when only the protocol is to be set.
 Note the Exim already has two private options, &%-pd%& and &%-ps%&, that refer
 to embedded Perl. It is therefore impossible to set a protocol value of &`d`&
 or &`s`& using this option (but that does not seem a real limitation).
 Note the Exim already has two private options, &%-pd%& and &%-ps%&, that refer
 to embedded Perl. It is therefore impossible to set a protocol value of &`d`&
 or &`s`& using this option (but that does not seem a real limitation).

+Repeated use of this option is not supported.

 
 .vitem &%-q%&
 .oindex "&%-q%&"
 
 .vitem &%-q%&
 .oindex "&%-q%&"


@@ -9963,7 +9967,7 @@ a regular expression, and a substitution string. For example:
 ${sg{abcdefabcdef}{abc}{xyz}}
 .endd
 yields &"xyzdefxyzdef"&. Because all three arguments are expanded before use,
 ${sg{abcdefabcdef}{abc}{xyz}}
 .endd
 yields &"xyzdefxyzdef"&. Because all three arguments are expanded before use,

-if any $ or \ characters are required in the regular expression or in the
+if any $, } or \ characters are required in the regular expression or in the

 substitution string, they have to be escaped. For example:
 .code
 ${sg{abcdef}{^(...)(...)\$}{\$2\$1}}
 substitution string, they have to be escaped. For example:
 .code
 ${sg{abcdef}{^(...)(...)\$}{\$2\$1}}


@@ -10114,7 +10118,15 @@ character. For example:
 .code
 ${addresses:>& Chief <ceo@up.stairs>, sec@base.ment (dogsbody)}
 .endd
 .code
 ${addresses:>& Chief <ceo@up.stairs>, sec@base.ment (dogsbody)}
 .endd

-expands to &`ceo@up.stairs&&sec@base.ment`&. Compare the &*address*& (singular)
+expands to &`ceo@up.stairs&&sec@base.ment`&. The string is expanded
+first, so if the expanded string starts with >, it may change the output
+separator unintentionally. This can be avoided by setting the output
+separator explicitly:
+.code
+${addresses:>:$h_from:}
+.endd
+
+Compare the &*address*& (singular)

 expansion item, which extracts the working address from a single RFC2822
 address. See the &*filter*&, &*map*&, and &*reduce*& items for ways of
 processing lists.
 expansion item, which extracts the working address from a single RFC2822
 address. See the &*filter*&, &*map*&, and &*reduce*& items for ways of
 processing lists.


@@ -11195,8 +11207,8 @@ example is:
 ${if match_domain{a.b.c}{x.y.z:a.b.c:p.q.r}{yes}{no}}
 .endd
 In each case, the second argument may contain any of the allowable items for a
 ${if match_domain{a.b.c}{x.y.z:a.b.c:p.q.r}{yes}{no}}
 .endd
 In each case, the second argument may contain any of the allowable items for a

-list of the appropriate type. Also, because the second argument (after
-expansion) is a standard form of list, it is possible to refer to a named list.
+list of the appropriate type. Also, because the second argument
+is a standard form of list, it is possible to refer to a named list.

 Thus, you can use conditions like this:
 .code
 ${if match_domain{$domain}{+local_domains}{...
 Thus, you can use conditions like this:
 .code
 ${if match_domain{$domain}{+local_domains}{...


@@ -12067,6 +12079,9 @@ when the ACL &%malware%& condition is true (see section &<<SECTscanvirus>>&).
 This variable contains the number of bytes in the longest line that was
 received as part of the message, not counting the line termination
 character(s).
 This variable contains the number of bytes in the longest line that was
 received as part of the message, not counting the line termination
 character(s).

+.new
+It is not valid if the &%spool_files_wireformat%& option is used.
+.wen

 
 .vitem &$message_age$&
 .cindex "message" "age of"
 
 .vitem &$message_age$&
 .cindex "message" "age of"


@@ -12109,6 +12124,12 @@ in bytes. The count starts from the character after the blank line that
 separates the body from the header. Newlines are included in the count. See
 also &$message_size$&, &$body_linecount$&, and &$body_zerocount$&.
 
 separates the body from the header. Newlines are included in the count. See
 also &$message_size$&, &$body_linecount$&, and &$body_zerocount$&.
 

+.new
+If the spool file is wireformat
+(see the &%spool_files_wireformat%& main option)
+the CRLF line-terminators are included in the count.
+.wen
+

 .vitem &$message_exim_id$&
 .vindex "&$message_exim_id$&"
 When a message is being received or delivered, this variable contains the
 .vitem &$message_exim_id$&
 .vindex "&$message_exim_id$&"
 When a message is being received or delivered, this variable contains the


@@ -12159,6 +12180,10 @@ deny message   = Too many lines in message header
 In the MAIL and RCPT ACLs, the value is zero because at that stage the
 message has not yet been received.
 
 In the MAIL and RCPT ACLs, the value is zero because at that stage the
 message has not yet been received.
 

+.new
+This variable is not valid if the &%spool_files_wireformat%& option is used.
+.wen
+

 .vitem &$message_size$&
 .cindex "size" "of message"
 .cindex "message" "size"
 .vitem &$message_size$&
 .cindex "size" "of message"
 .cindex "message" "size"


@@ -12779,6 +12804,15 @@ argument, that is, the text that follows the command name, with leading white
 space removed. Following the introduction of &$smtp_command$&, this variable is
 somewhat redundant, but is retained for backwards compatibility.
 
 space removed. Following the introduction of &$smtp_command$&, this variable is
 somewhat redundant, but is retained for backwards compatibility.
 

+.new
+.vitem &$smtp_command_history$&
+.cindex SMTP "command history"
+.vindex "&$smtp_command_history$&"
+A comma-separated list (with no whitespace) of the most-recent SMTP commands
+received, in time-order left to right.  Only a limited number of commands
+are remembered.
+.wen
+

 .vitem &$smtp_count_at_connection_start$&
 .vindex "&$smtp_count_at_connection_start$&"
 This variable is set greater than zero only in processes spawned by the Exim
 .vitem &$smtp_count_at_connection_start$&
 .vindex "&$smtp_count_at_connection_start$&"
 This variable is set greater than zero only in processes spawned by the Exim


@@ -13566,6 +13600,7 @@ listed in more than one group.
 .row &%message_body_visible%&        "how much to show in &$message_body$&"
 .row &%mua_wrapper%&                 "run in &""MUA wrapper""& mode"
 .row &%print_topbitchars%&           "top-bit characters are printing"
 .row &%message_body_visible%&        "how much to show in &$message_body$&"
 .row &%mua_wrapper%&                 "run in &""MUA wrapper""& mode"
 .row &%print_topbitchars%&           "top-bit characters are printing"

+.row &%spool_wireformat%&            "use wire-format spool data files when possible"

 .row &%timezone%&                    "force time zone"
 .endtable
 
 .row &%timezone%&                    "force time zone"
 .endtable
 


@@ -13585,6 +13620,7 @@ listed in more than one group.
 .section "Privilege controls" "SECID98"
 .table2
 .row &%admin_groups%&                "groups that are Exim admin users"
 .section "Privilege controls" "SECID98"
 .table2
 .row &%admin_groups%&                "groups that are Exim admin users"

+.row &%commandline_checks_require_admin%& "require admin for various checks"

 .row &%deliver_drop_privilege%&      "drop root for delivery processes"
 .row &%local_from_check%&            "insert &'Sender:'& if necessary"
 .row &%local_from_prefix%&           "for testing &'From:'& for local sender"
 .row &%deliver_drop_privilege%&      "drop root for delivery processes"
 .row &%local_from_check%&            "insert &'Sender:'& if necessary"
 .row &%local_from_prefix%&           "for testing &'From:'& for local sender"


@@ -14447,6 +14483,14 @@ The CHUNKING extension (RFC3030) will be advertised in the EHLO message to
 these hosts.
 Hosts may use the BDAT command as an alternate to DATA.
 
 these hosts.
 Hosts may use the BDAT command as an alternate to DATA.
 

+.new
+.option commandline_checks_require_admin main boolean &`false`&
+.cindex "restricting access to features"
+This option restricts various basic checking features to require an
+administrative user.
+This affects most of the &%-b*%& options, such as &%-be%&.
+.wen
+

 .option debug_store main boolean &`false`&
 .cindex debugging "memory corruption"
 .cindex memory debugging
 .option debug_store main boolean &`false`&
 .cindex debugging "memory corruption"
 .cindex memory debugging


@@ -15928,12 +15972,13 @@ different spool directories.
 
 
 .option prod_requires_admin main boolean true
 
 
 .option prod_requires_admin main boolean true

+.cindex "restricting access to features"

 .oindex "&%-M%&"
 .oindex "&%-R%&"
 .oindex "&%-q%&"
 The &%-M%&, &%-R%&, and &%-q%& command-line options require the caller to be an
 admin user unless &%prod_requires_admin%& is set false. See also
 .oindex "&%-M%&"
 .oindex "&%-R%&"
 .oindex "&%-q%&"
 The &%-M%&, &%-R%&, and &%-q%& command-line options require the caller to be an
 admin user unless &%prod_requires_admin%& is set false. See also

-&%queue_list_requires_admin%&.
+&%queue_list_requires_admin%& and &%commandline_checks_require_admin%&.

 
 
 .option qualify_domain main string "see below"
 
 
 .option qualify_domain main string "see below"


@@ -15972,10 +16017,12 @@ next queue run. See also &%hold_domains%& and &%queue_smtp_domains%&.
 
 
 .option queue_list_requires_admin main boolean true
 
 
 .option queue_list_requires_admin main boolean true

+.cindex "restricting access to features"

 .oindex "&%-bp%&"
 The &%-bp%& command-line option, which lists the messages that are on the
 queue, requires the caller to be an admin user unless
 .oindex "&%-bp%&"
 The &%-bp%& command-line option, which lists the messages that are on the
 queue, requires the caller to be an admin user unless

-&%queue_list_requires_admin%& is set false. See also &%prod_requires_admin%&.
+&%queue_list_requires_admin%& is set false.
+See also &%prod_requires_admin%& and &%commandline_checks_require_admin%&.

 
 
 .option queue_only main boolean false
 
 
 .option queue_only main boolean false


@@ -16821,6 +16868,32 @@ as failures in the configuration file.
 By using this option to override the compiled-in path, it is possible to run
 tests of Exim without using the standard spool.
 
 By using this option to override the compiled-in path, it is possible to run
 tests of Exim without using the standard spool.
 

+.new
+.option spool_wireformat main boolean false
+.cindex "spool directory" "file formats"
+If this option is set, Exim may for some messages use an alternate format
+for data-files in the spool which matches the wire format.
+Doing this permits more efficient message reception and transmission.
+Currently it is only done for messages received using the EMSTP CHUNKING
+option.
+
+The following variables will not have useful values:
+.code
+$max_received_linelength
+$body_linecount
+$body_zerocount
+.endd
+
+Users of the local_scan() API (see &<<CHAPlocalscan>>&),
+and any external programs which are passed a reference to a message data file
+(except via the &"regex"&, &"malware"& or &"spam"&) ACL conditions)
+will need to be aware of the potential different format.
+
+Using any of the ACL conditions noted will negate the reception benefit
+(as a Unix-mbox-format file is contructed for them).
+The transimssion benefit is maintained.
+.wen
+

 .option sqlite_lock_timeout main time 5s
 .cindex "sqlite lookup type" "lock timeout"
 This option controls the timeout that the &(sqlite)& lookup uses when trying to
 .option sqlite_lock_timeout main time 5s
 .cindex "sqlite lookup type" "lock timeout"
 This option controls the timeout that the &(sqlite)& lookup uses when trying to


@@ -19416,6 +19489,10 @@ instead of TRY_AGAIN. That is why the default action is to try a DNS
 lookup first. Only if that gives a definite &"no such host"& is the local
 function called.
 
 lookup first. Only if that gives a definite &"no such host"& is the local
 function called.
 

+&*Compatibility*&: From Exim 4.85 until fixed for 4.90, there was an
+inadvertent constraint that a transport name as an option had to be the last
+option specified.
+

 
 
 If no IP address for a host can be found, what happens is controlled by the
 
 
 If no IP address for a host can be found, what happens is controlled by the


@@ -20293,11 +20370,15 @@ relative path is then passed to the transport unmodified.
 
 
 .option forbid_blackhole redirect boolean false
 
 
 .option forbid_blackhole redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 If this option is true, the &':blackhole:'& item may not appear in a
 redirection list.
 
 
 .option forbid_exim_filter redirect boolean false
 If this option is true, the &':blackhole:'& item may not appear in a
 redirection list.
 
 
 .option forbid_exim_filter redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 If this option is set true, only Sieve filters are permitted when
 &%allow_filter%& is true.
 
 If this option is set true, only Sieve filters are permitted when
 &%allow_filter%& is true.
 


@@ -20305,7 +20386,9 @@ If this option is set true, only Sieve filters are permitted when
 
 
 .option forbid_file redirect boolean false
 
 
 .option forbid_file redirect boolean false

+.cindex "restricting access to features"

 .cindex "delivery" "to file; forbidding"
 .cindex "delivery" "to file; forbidding"

+.cindex "filter" "locking out certain features"

 .cindex "Sieve filter" "forbidding delivery to a file"
 .cindex "Sieve filter" "&""keep""& facility; disabling"
 If this option is true, this router may not generate a new address that
 .cindex "Sieve filter" "forbidding delivery to a file"
 .cindex "Sieve filter" "&""keep""& facility; disabling"
 If this option is true, this router may not generate a new address that


@@ -20316,17 +20399,22 @@ locks out the Sieve's &"keep"& facility.
 
 
 .option forbid_filter_dlfunc redirect boolean false
 
 
 .option forbid_filter_dlfunc redirect boolean false

+.cindex "restricting access to features"

 .cindex "filter" "locking out certain features"
 If this option is true, string expansions in Exim filters are not allowed to
 make use of the &%dlfunc%& expansion facility to run dynamically loaded
 functions.
 
 .option forbid_filter_existstest redirect boolean false
 .cindex "filter" "locking out certain features"
 If this option is true, string expansions in Exim filters are not allowed to
 make use of the &%dlfunc%& expansion facility to run dynamically loaded
 functions.
 
 .option forbid_filter_existstest redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 .cindex "expansion" "statting a file"
 If this option is true, string expansions in Exim filters are not allowed to
 make use of the &%exists%& condition or the &%stat%& expansion item.
 
 .option forbid_filter_logwrite redirect boolean false
 .cindex "expansion" "statting a file"
 If this option is true, string expansions in Exim filters are not allowed to
 make use of the &%exists%& condition or the &%stat%& expansion item.
 
 .option forbid_filter_logwrite redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 If this option is true, use of the logging facility in Exim filters is not
 permitted. Logging is in any case available only if the filter is being run
 under some unprivileged uid (which is normally the case for ordinary users'
 If this option is true, use of the logging facility in Exim filters is not
 permitted. Logging is in any case available only if the filter is being run
 under some unprivileged uid (which is normally the case for ordinary users'


@@ -20334,27 +20422,37 @@ under some unprivileged uid (which is normally the case for ordinary users'
 
 
 .option forbid_filter_lookup redirect boolean false
 
 
 .option forbid_filter_lookup redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 If this option is true, string expansions in Exim filter files are not allowed
 to make use of &%lookup%& items.
 
 
 .option forbid_filter_perl redirect boolean false
 If this option is true, string expansions in Exim filter files are not allowed
 to make use of &%lookup%& items.
 
 
 .option forbid_filter_perl redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 This option has an effect only if Exim is built with embedded Perl support. If
 it is true, string expansions in Exim filter files are not allowed to make use
 of the embedded Perl support.
 
 
 .option forbid_filter_readfile redirect boolean false
 This option has an effect only if Exim is built with embedded Perl support. If
 it is true, string expansions in Exim filter files are not allowed to make use
 of the embedded Perl support.
 
 
 .option forbid_filter_readfile redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 If this option is true, string expansions in Exim filter files are not allowed
 to make use of &%readfile%& items.
 
 
 .option forbid_filter_readsocket redirect boolean false
 If this option is true, string expansions in Exim filter files are not allowed
 to make use of &%readfile%& items.
 
 
 .option forbid_filter_readsocket redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 If this option is true, string expansions in Exim filter files are not allowed
 to make use of &%readsocket%& items.
 
 
 .option forbid_filter_reply redirect boolean false
 If this option is true, string expansions in Exim filter files are not allowed
 to make use of &%readsocket%& items.
 
 
 .option forbid_filter_reply redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 If this option is true, this router may not generate an automatic reply
 message. Automatic replies can be generated only from Exim or Sieve filter
 files, not from traditional forward files. This option is forced to be true if
 If this option is true, this router may not generate an automatic reply
 message. Automatic replies can be generated only from Exim or Sieve filter
 files, not from traditional forward files. This option is forced to be true if


@@ -20362,11 +20460,15 @@ files, not from traditional forward files. This option is forced to be true if
 
 
 .option forbid_filter_run redirect boolean false
 
 
 .option forbid_filter_run redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 If this option is true, string expansions in Exim filter files are not allowed
 to make use of &%run%& items.
 
 
 .option forbid_include redirect boolean false
 If this option is true, string expansions in Exim filter files are not allowed
 to make use of &%run%& items.
 
 
 .option forbid_include redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 If this option is true, items of the form
 .code
 :include:<path name>
 If this option is true, items of the form
 .code
 :include:<path name>


@@ -20375,6 +20477,8 @@ are not permitted in non-filter redirection lists.
 
 
 .option forbid_pipe redirect boolean false
 
 
 .option forbid_pipe redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 .cindex "delivery" "to pipe; forbidding"
 If this option is true, this router may not generate a new address which
 specifies delivery to a pipe, either from an Exim filter or from a conventional
 .cindex "delivery" "to pipe; forbidding"
 If this option is true, this router may not generate a new address which
 specifies delivery to a pipe, either from an Exim filter or from a conventional


@@ -20382,6 +20486,8 @@ forward file. This option is forced to be true if &%one_time%& is set.
 
 
 .option forbid_sieve_filter redirect boolean false
 
 
 .option forbid_sieve_filter redirect boolean false

+.cindex "restricting access to features"
+.cindex "filter" "locking out certain features"

 If this option is set true, only Exim filters are permitted when
 &%allow_filter%& is true.
 
 If this option is set true, only Exim filters are permitted when
 &%allow_filter%& is true.
 


@@ -22046,10 +22152,14 @@ the obvious value which users understand most easily.
 
 The value of the option is expanded, and must then be a numerical value
 (decimal point allowed), optionally followed by one of the letters K, M, or G,
 
 The value of the option is expanded, and must then be a numerical value
 (decimal point allowed), optionally followed by one of the letters K, M, or G,

-for kilobytes, megabytes, or gigabytes. If Exim is running on a system with
+for kilobytes, megabytes, or gigabytes, optionally followed by a slash
+and further option modifiers. If Exim is running on a system with

 large file support (Linux and FreeBSD have this), mailboxes larger than 2G can
 be handled.
 
 large file support (Linux and FreeBSD have this), mailboxes larger than 2G can
 be handled.
 

+The option modifier &%no_check%& can be used to force delivery even if the over
+quota condition is met. The quota gets updated as usual.
+

 &*Note*&: A value of zero is interpreted as &"no quota"&.
 
 The expansion happens while Exim is running as root, before it changes uid for
 &*Note*&: A value of zero is interpreted as &"no quota"&.
 
 The expansion happens while Exim is running as root, before it changes uid for


@@ -22084,6 +22194,8 @@ can only be used if &%quota%& is also set. The value is expanded; an expansion
 failure causes delivery to be deferred. A value of zero is interpreted as
 &"no quota"&.
 
 failure causes delivery to be deferred. A value of zero is interpreted as
 &"no quota"&.
 

+The option modifier &%no_check%& can be used to force delivery even if the over
+quota condition is met. The quota gets updated as usual.

 
 .option quota_is_inclusive appendfile boolean true
 See &%quota%& above.
 
 .option quota_is_inclusive appendfile boolean true
 See &%quota%& above.


@@ -23694,7 +23806,9 @@ of the message. Its value must not be zero. See also &%final_timeout%&.
 .option dkim_private_key smtp string&!! unset
 .option dkim_canon smtp string&!! unset
 .option dkim_strict smtp string&!! unset
 .option dkim_private_key smtp string&!! unset
 .option dkim_canon smtp string&!! unset
 .option dkim_strict smtp string&!! unset

-.option dkim_sign_headers smtp string&!! unset
+.option dkim_sign_headers smtp string&!! per RFC
+.option dkim_hash smtp string&!! sha256
+.option dkim_identity smtp string&!! unset

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


@@ -24033,7 +24147,7 @@ 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.
 

-.option hosts_try_fastopen smtp "host list!!" unset
+.option hosts_try_fastopen smtp "host list&!!" unset

 .cindex "fast open, TCP" "enabling, in client"
 .cindex "TCP Fast Open" "enabling, in client"
 .cindex "RFC 7413" "TCP Fast Open"
 .cindex "fast open, TCP" "enabling, in client"
 .cindex "TCP Fast Open" "enabling, in client"
 .cindex "RFC 7413" "TCP Fast Open"


@@ -24049,6 +24163,9 @@ as the initiator must present a cookie in the SYN segment.
 
 On (at least some) current Linux distributions the facility must be enabled
 in the kernel by the sysadmin before the support is usable.
 
 On (at least some) current Linux distributions the facility must be enabled
 in the kernel by the sysadmin before the support is usable.

+There is no option for control of the server side; if the system supports
+it it is always enebled.  Note that legthy operations in the connect ACL,
+such as DNSBL lookups, will still delay the emission of the SMTP banner.

 
 .option hosts_try_prdr smtp "host list&!!" *
 .cindex "PRDR" "enabling, optional in client"
 
 .option hosts_try_prdr smtp "host list&!!" *
 .cindex "PRDR" "enabling, optional in client"


@@ -27631,13 +27748,22 @@ built, then you have SNI support).
          "SECTmulmessam"
 .cindex "multiple SMTP deliveries with TLS"
 .cindex "TLS" "multiple message deliveries"
          "SECTmulmessam"
 .cindex "multiple SMTP deliveries with TLS"
 .cindex "TLS" "multiple message deliveries"

+.new

 Exim sends multiple messages down the same TCP/IP connection by starting up
 an entirely new delivery process for each message, passing the socket from
 one process to the next. This implementation does not fit well with the use
 of TLS, because there is quite a lot of state information associated with a TLS
 connection, not just a socket identification. Passing all the state information
 Exim sends multiple messages down the same TCP/IP connection by starting up
 an entirely new delivery process for each message, passing the socket from
 one process to the next. This implementation does not fit well with the use
 of TLS, because there is quite a lot of state information associated with a TLS
 connection, not just a socket identification. Passing all the state information

-to a new process is not feasible. Consequently, Exim shuts down an existing TLS
-session before passing the socket to a new process. The new process may then
+to a new process is not feasible. Consequently, for sending using TLS Exim
+starts an additional proxy process for handling the encryption, piping the
+unencrypted data stream from and to the delivery processes.
+
+An older mode of operation can be enabled on a per-host basis by the
+&%hosts_noproxy_tls%& option on the &(smtp)& transport.  If the host matches
+this list the proxy process descibed above is not used; instead Exim
+.wen
+shuts down an existing TLS session being run by the delivery process
+before passing the socket to a new process. The new process may then

 try to start a new TLS session, and if successful, may try to re-authenticate
 if AUTH is in use, before sending the next message.
 
 try to start a new TLS session, and if successful, may try to re-authenticate
 if AUTH is in use, before sending the next message.
 


@@ -28965,6 +29091,11 @@ and cannot depend on content of received headers.
 Note also that headers cannot be
 modified by any of the post-data ACLs (DATA, MIME and DKIM).
 Headers may be modified by routers (subject to the above) and transports.
 Note also that headers cannot be
 modified by any of the post-data ACLs (DATA, MIME and DKIM).
 Headers may be modified by routers (subject to the above) and transports.

+.new
+The Received-By: header is generated as soon as the body reception starts,
+rather than the traditional time after the full message is received;
+this will affect the timestamp.
+.wen

 
 All the usual ACLs are called; if one results in the message being
 rejected, all effort spent in delivery (including the costs on
 
 All the usual ACLs are called; if one results in the message being
 rejected, all effort spent in delivery (including the costs on


@@ -31607,14 +31738,18 @@ an address (which may be an IP address and port, or the path of a Unix socket),
 a commandline to send (may include a single %s which will be replaced with
 the path to the mail file to be scanned),
 an RE to trigger on from the returned data,
 a commandline to send (may include a single %s which will be replaced with
 the path to the mail file to be scanned),
 an RE to trigger on from the returned data,

-an RE to extract malware_name from the returned data.
+and an RE to extract malware_name from the returned data.

 For example:
 .code
 For example:
 .code

-av_scanner = sock:127.0.0.1 6001:%s:(SPAM|VIRUS):(.*)\$
+av_scanner = sock:127.0.0.1 6001:%s:(SPAM|VIRUS):(.*)$

 .endd
 .endd

-Default for the socket specifier is &_/tmp/malware.sock_&.
-Default for the commandline is &_%s\n_&.
-Both regular-expressions are required.
+.new
+Note that surrounding whitespace is stripped from each option, meaning
+there is no way to specify a trailing newline.
+The socket specifier and both regular-expressions are required.
+Default for the commandline is &_%s\n_& (note this does have a trailing newline);
+specify an empty element to get this.
+.wen

 
 .vitem &%sophie%&
 .cindex "virus scanners" "Sophos and Sophie"
 
 .vitem &%sophie%&
 .cindex "virus scanners" "Sophos and Sophie"


@@ -32454,9 +32589,15 @@ C variables are as follows:
 .vlist
 .vitem &*int&~body_linecount*&
 This variable contains the number of lines in the message's body.
 .vlist
 .vitem &*int&~body_linecount*&
 This variable contains the number of lines in the message's body.

+.new
+It is not valid if the &%spool_files_wireformat%& option is used.
+.wen

 
 .vitem &*int&~body_zerocount*&
 This variable contains the number of binary zero bytes in the message's body.
 
 .vitem &*int&~body_zerocount*&
 This variable contains the number of binary zero bytes in the message's body.

+.new
+It is not valid if the &%spool_files_wireformat%& option is used.
+.wen

 
 .vitem &*unsigned&~int&~debug_selector*&
 This variable is set to zero when no debugging is taking place. Otherwise, it
 
 .vitem &*unsigned&~int&~debug_selector*&
 This variable is set to zero when no debugging is taking place. Otherwise, it


@@ -35898,6 +36039,7 @@ the following table:
 &`I   `&        local interface used
 &`K   `&        CHUNKING extension used
 &`id  `&        message id for incoming message
 &`I   `&        local interface used
 &`K   `&        CHUNKING extension used
 &`id  `&        message id for incoming message

+&`M8S `&        8BITMIME status for incoming message

 &`P   `&        on &`<=`& lines: protocol used
 &`    `&        on &`=>`& and &`**`& lines: return path
 &`PRDR`&        PRDR extension used
 &`P   `&        on &`<=`& lines: protocol used
 &`    `&        on &`=>`& and &`**`& lines: return path
 &`PRDR`&        PRDR extension used


@@ -35911,6 +36053,7 @@ the following table:
 &`SNI `&        server name indication from TLS client hello
 &`ST  `&        shadow transport name
 &`T   `&        on &`<=`& lines: message subject (topic)
 &`SNI `&        server name indication from TLS client hello
 &`ST  `&        shadow transport name
 &`T   `&        on &`<=`& lines: message subject (topic)

+&`TFO `&        connection took advantage of TCP Fast Open

 &`    `&        on &`=>`& &`**`& and &`==`& lines: transport name
 &`U   `&        local user or RFC 1413 identity
 &`X   `&        TLS cipher suite
 &`    `&        on &`=>`& &`**`& and &`==`& lines: transport name
 &`U   `&        local user or RFC 1413 identity
 &`X   `&        TLS cipher suite


@@ -35992,6 +36135,7 @@ selection marked by asterisks:
 &` incoming_interface         `&  local interface on <= and => lines
 &` incoming_port              `&  remote port on <= lines
 &`*lost_incoming_connection   `&  as it says (includes timeouts)
 &` incoming_interface         `&  local interface on <= and => lines
 &` incoming_port              `&  remote port on <= lines
 &`*lost_incoming_connection   `&  as it says (includes timeouts)

+&` millisec                   `&  millisecond timestamps and QT,DT,D times

 &` outgoing_interface         `&  local interface on => lines
 &` outgoing_port              `&  add remote port to => lines
 &`*queue_run                  `&  start and end queue runs
 &` outgoing_interface         `&  local interface on => lines
 &` outgoing_port              `&  add remote port to => lines
 &`*queue_run                  `&  start and end queue runs


@@ -36081,6 +36225,8 @@ process is started because &%queue_only%& is set or &%-odq%& was used.
 .cindex "log" "delivery duration"
 &%deliver_time%&: For each delivery, the amount of real time it has taken to
 perform the actual delivery is logged as DT=<&'time'&>, for example, &`DT=1s`&.
 .cindex "log" "delivery duration"
 &%deliver_time%&: For each delivery, the amount of real time it has taken to
 perform the actual delivery is logged as DT=<&'time'&>, for example, &`DT=1s`&.

+If millisecond logging is enabled, short times will be shown with greater
+precision, eg. &`DT=0.304`&.

 .next
 .cindex "log" "message size on delivery"
 .cindex "size" "of message"
 .next
 .cindex "log" "message size on delivery"
 .cindex "size" "of message"


@@ -36156,6 +36302,14 @@ important with the widening use of NAT (see RFC 2505).
 &%lost_incoming_connection%&: A log line is written when an incoming SMTP
 connection is unexpectedly dropped.
 .next
 &%lost_incoming_connection%&: A log line is written when an incoming SMTP
 connection is unexpectedly dropped.
 .next

+.new
+.cindex "log" "millisecond timestamps"
+.cindex millisecond logging
+.cindex timstamps "millisecond, in logs"
+&%millisec%&: Timestamps have a period and three decimal places of finer granularity
+appended to the seconds value.
+.wen
+.next

 .cindex "log" "outgoing interface"
 .cindex "log" "local interface"
 .cindex "log" "local address and port"
 .cindex "log" "outgoing interface"
 .cindex "log" "local interface"
 .cindex "log" "local address and port"


@@ -36194,6 +36348,8 @@ includes reception time as well as the delivery time for the current address.
 This means that it may be longer than the difference between the arrival and
 delivery log line times, because the arrival log line is not written until the
 message has been successfully received.
 This means that it may be longer than the difference between the arrival and
 delivery log line times, because the arrival log line is not written until the
 message has been successfully received.

+If millisecond logging is enabled, short times will be shown with greater
+precision, eg. &`QT=1.578s`&.

 .next
 &%queue_time_overall%&: The amount of time the message has been in the queue on
 the local host is logged as QT=<&'time'&> on &"Completed"& lines, for
 .next
 &%queue_time_overall%&: The amount of time the message has been in the queue on
 the local host is logged as QT=<&'time'&> on &"Completed"& lines, for


@@ -37896,6 +38052,13 @@ the contents of files on the spool via the Exim monitor (which runs
 unprivileged), Exim must be built to allow group read access to its spool
 files.
 
 unprivileged), Exim must be built to allow group read access to its spool
 files.
 

+.new
+By default, regular users are trusted to perform basic testing and
+introspection commands, as themselves.  This setting can be tightened by
+setting the &%commandline_checks_require_admin%& option.
+This affects most of the checking options,
+such as &%-be%& and anything else &%-b*%&.
+.wen

 
 
 .section "Spool files" "SECID275"
 
 
 .section "Spool files" "SECID275"


@@ -38016,6 +38179,13 @@ file remains in existence. When Exim next processes the message, it notices the
 -J file and uses it to update the -H file before starting the next delivery
 attempt.
 
 -J file and uses it to update the -H file before starting the next delivery
 attempt.
 

+.new
+Files whose names end with -K or .eml may also be seen in the spool.
+These are temporaries used for DKIM or malware processing, when that is used.
+They should be tidied up by normal operations; any old ones are probably
+relics of crashes and can be removed.
+.wen
+

 .section "Format of the -H file" "SECID282"
 .cindex "uid (user id)" "in spool file"
 .cindex "gid (group id)" "in spool file"
 .section "Format of the -H file" "SECID282"
 .cindex "uid (user id)" "in spool file"
 .cindex "gid (group id)" "in spool file"


@@ -38093,8 +38263,8 @@ The address of an authenticated sender &-- the value of the
 &$authenticated_sender$& variable.
 
 .vitem "&%-body_linecount%&&~<&'number'&>"
 &$authenticated_sender$& variable.
 
 .vitem "&%-body_linecount%&&~<&'number'&>"

-This records the number of lines in the body of the message, and is always
-present.
+This records the number of lines in the body of the message, and is
+present unless &%-spool_file_wireformat%& is.

 
 .vitem "&%-body_zerocount%&&~<&'number'&>"
 This records the number of binary zero bytes in the body of the message, and is
 
 .vitem "&%-body_zerocount%&&~<&'number'&>"
 This records the number of binary zero bytes in the body of the message, and is


@@ -38176,6 +38346,14 @@ to ensure that the caller is displayed in queue listings).
 If a message was scanned by SpamAssassin, this is present. It records the value
 of &$spam_score_int$&.
 
 If a message was scanned by SpamAssassin, this is present. It records the value
 of &$spam_score_int$&.
 

+.new
+.vitem &%-spool_file_wireformat%&
+The -D file for this message is in wire-format (for ESMTP CHUNKING)
+rather than Unix-format.
+The line-ending is CRLF rather than newline.
+There is still, however, no leading-dot-stuffing.
+.wen
+

 .vitem &%-tls_certificate_verified%&
 A TLS certificate was received from the client that sent this message, and the
 certificate was verified by the server.
 .vitem &%-tls_certificate_verified%&
 A TLS certificate was received from the client that sent this message, and the
 certificate was verified by the server.


@@ -38283,6 +38461,20 @@ unqualified domain &'foundation'&.
 .ecindex IIDforspo2
 .ecindex IIDforspo3
 
 .ecindex IIDforspo2
 .ecindex IIDforspo3
 

+.new
+.section "Format of the -D file" "SECID282a"
+The data file is traditionally in Unix-standard format: lines are ended with
+an ASCII newline character.
+However, when the &%spool_wireformat%& main option is used some -D files
+can have an alternate format.
+This is flagged by a &%-spool_file_wireformat%& line in the corresponding -H file.
+The -D file lines (not including the first name-component line) are
+suitable for direct copying to the wire when transmitting using the
+ESMTP CHUNKING option, meaning lower processing overhead.
+Lines are terminated with an ASCII CRLF pair.
+There is no dot-stuffing (and no dot-termination).
+.wen
+

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


@@ -38346,13 +38538,15 @@ while expanding the remaining signing options.
 .wen
 If it is empty after expansion, DKIM signing is not done.
 
 .wen
 If it is empty after expansion, DKIM signing is not done.
 

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

 This sets the key selector string.
 This sets the key selector string.

-You can use the &%$dkim_domain%& expansion variable to look up a matching selector.
-The result is put in the expansion
+.new
+After expansion, which can use &$dkim_domain$&, this can be a list.
+Each element in turn is put in the expansion

 variable &%$dkim_selector%& which may be used in the &%dkim_private_key%&
 option along with &%$dkim_domain%&.
 variable &%$dkim_selector%& which may be used in the &%dkim_private_key%&
 option along with &%$dkim_domain%&.

-If the option is empty after expansion, DKIM signing is not done.
+If the option is empty after expansion, DKIM signing is not done for this domain.
+.wen

 
 .option dkim_private_key smtp string&!! unset
 This sets the private key to use.
 
 .option dkim_private_key smtp string&!! unset
 This sets the private key to use.


@@ -38371,6 +38565,19 @@ is set.
 .endlist
 If the option is empty after expansion, DKIM signing is not done.
 
 .endlist
 If the option is empty after expansion, DKIM signing is not done.
 

+.new
+.option dkim_hash smtp string&!! sha256
+Can be set alternatively to &"sha1"& to use an alternate hash
+method.  Note that sha1 is now condidered insecure, and deprecated.
+
+.option dkim_identity smtp string&!! unset
+If set after expansion, the value is used to set an "i=" tag in
+the signing header.  The DKIM standards restrict the permissible
+syntax of this optional tag to a mail address, with possibly-empty
+local part, an @, and a domain identical to or subdomain of the "d="
+tag value.  Note that Exim does not check the value.
+.wen
+

 .option dkim_canon smtp string&!! unset
 This option sets the canonicalization method used when signing a message.
 The DKIM RFC currently supports two methods: "simple" and "relaxed".
 .option dkim_canon smtp string&!! unset
 This option sets the canonicalization method used when signing a message.
 The DKIM RFC currently supports two methods: "simple" and "relaxed".


@@ -38384,11 +38591,13 @@ either "1" or "true", Exim will defer. Otherwise Exim will send the message
 unsigned. You can use the &%$dkim_domain%& and &%$dkim_selector%& expansion
 variables here.
 
 unsigned. You can use the &%$dkim_domain%& and &%$dkim_selector%& expansion
 variables here.
 

-.option dkim_sign_headers smtp string&!! unset
-If set, this option must expand to (or be specified as) a colon-separated
+.option dkim_sign_headers smtp string&!! see below
+If set, this option must expand to a colon-separated

 list of header names. Headers with these names will be included in the message
 signature.
 When unspecified, the header names recommended in RFC4871 will be used.
 list of header names. Headers with these names will be included in the message
 signature.
 When unspecified, the header names recommended in RFC4871 will be used.

+The default list is available for the expansion in the macro
+"_DKIM_SIGN_HEADERS".

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


@@ -38399,7 +38608,7 @@ Verification of DKIM signatures in SMTP incoming email is implemented via the
 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.
 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 it is
+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
 summarily dropped (having wasted the transmission effort).
 
 To evaluate the signature in the ACL a large number of expansion variables


@@ -38502,7 +38711,7 @@ The algorithm used. One of 'rsa-sha1' or 'rsa-sha256'.
 .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'.
 

-.vitem &%dkim_canon_headers%&
+.vitem &%$dkim_canon_headers%&

 The header canonicalization method. One of 'relaxed' or 'simple'.
 
 .vitem &%$dkim_copiedheaders%&
 The header canonicalization method. One of 'relaxed' or 'simple'.
 
 .vitem &%$dkim_copiedheaders%&