SOCKS: Add log_selector support.

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

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index c6aeea145db4f67e292299c92129bca5cbdf751c..418cb1a11f2d95de5dac6d3b8151cd7a7873445e 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -45,14 +45,14 @@
 . Update the Copyright year (only) when changing content.
 . /////////////////////////////////////////////////////////////////////////////
 
 . Update the Copyright year (only) when changing content.
 . /////////////////////////////////////////////////////////////////////////////
 

-.set previousversion "4.84"
+.set previousversion "4.86"

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

-2014
+2015

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


@@ -1575,7 +1575,7 @@ If a host is unreachable for a period of time, a number of messages may be
 waiting for it by the time it recovers, and sending them in a single SMTP
 connection is clearly beneficial. Whenever a delivery to a remote host is
 deferred,
 waiting for it by the time it recovers, and sending them in a single SMTP
 connection is clearly beneficial. Whenever a delivery to a remote host is
 deferred,

-.cindex "hints database"
+.cindex "hints database" "deferred deliveries"

 Exim makes a note in its hints database, and whenever a successful
 SMTP delivery has happened, it looks to see if any other messages are waiting
 for the same host. If any are found, they are sent over the same SMTP
 Exim makes a note in its hints database, and whenever a successful
 SMTP delivery has happened, it looks to see if any other messages are waiting
 for the same host. If any are found, they are sent over the same SMTP


@@ -1860,7 +1860,7 @@ described RFC 2047. This makes it possible to transmit characters that are not
 in the ASCII character set, and to label them as being in a particular
 character set. When Exim is inspecting header lines by means of the &%$h_%&
 mechanism, it decodes them, and translates them into a specified character set
 in the ASCII character set, and to label them as being in a particular
 character set. When Exim is inspecting header lines by means of the &%$h_%&
 mechanism, it decodes them, and translates them into a specified character set

-(default ISO-8859-1). The translation is possible only if the operating system
+(default is set at build time). The translation is possible only if the operating system

 supports the &[iconv()]& function.
 
 However, some of the operating systems that supply &[iconv()]& do not support
 supports the &[iconv()]& function.
 
 However, some of the operating systems that supply &[iconv()]& do not support


@@ -1985,10 +1985,10 @@ Two different types of DNS record for handling IPv6 addresses have been
 defined. AAAA records (analogous to A records for IPv4) are in use, and are
 currently seen as the mainstream. Another record type called A6 was proposed
 as better than AAAA because it had more flexibility. However, it was felt to be
 defined. AAAA records (analogous to A records for IPv4) are in use, and are
 currently seen as the mainstream. Another record type called A6 was proposed
 as better than AAAA because it had more flexibility. However, it was felt to be

-over-complex, and its status was reduced to &"experimental"&. It is not known
-if anyone is actually using A6 records. Exim has support for A6 records, but
-this is included only if you set &`SUPPORT_A6=YES`& in &_Local/Makefile_&. The
-support has not been tested for some time.
+over-complex, and its status was reduced to &"experimental"&.
+Exim used to
+have a compile option for including A6 record support but this has now been
+withdrawn.

 
 
 
 
 
 


@@ -2032,9 +2032,6 @@ For example, on a Sun system running Solaris 8, the directory
 .cindex "symbolic link" "to source files"
 Symbolic links to relevant source files are installed in the build directory.
 
 .cindex "symbolic link" "to source files"
 Symbolic links to relevant source files are installed in the build directory.
 

-&*Warning*&: The &%-j%& (parallel) flag must not be used with &'make'&; the
-building process fails if it is set.
-

 If this is the first time &'make'& has been run, it calls a script that builds
 a make file inside the build directory, using the configuration files from the
 &_Local_& directory. The new make file is then passed to another instance of
 If this is the first time &'make'& has been run, it calls a script that builds
 a make file inside the build directory, using the configuration files from the
 &_Local_& directory. The new make file is then passed to another instance of


@@ -3110,8 +3107,12 @@ users, the output is as in this example:
 .code
 mysql_servers = <value not displayable>
 .endd
 .code
 mysql_servers = <value not displayable>
 .endd

-If &%configure_file%& is given as an argument, the name of the run time
-configuration file is output.
+If &%config%& is given as an argument, the config is
+output, as it was parsed, any include file resolved, any comment removed.
+
+If &%config_file%& is given as an argument, the name of the run time
+configuration file is output. (&%configure_file%& works too, for
+backward compatibility.)

 If a list of configuration files was supplied, the value that is output here
 is the name of the file that was actually used.
 
 If a list of configuration files was supplied, the value that is output here
 is the name of the file that was actually used.
 


@@ -3551,6 +3552,9 @@ example:
 exim '-D ABC = something' ...
 .endd
 &%-D%& may be repeated up to 10 times on a command line.
 exim '-D ABC = something' ...
 .endd
 &%-D%& may be repeated up to 10 times on a command line.

+.new
+Only macro names up to 22 letters long can be set.
+.wen

 
 
 .vitem &%-d%&<&'debug&~options'&>
 
 
 .vitem &%-d%&<&'debug&~options'&>


@@ -3811,6 +3815,12 @@ This option is not intended for use by external callers. It is used internally
 by Exim in conjunction with the &%-MC%& option. It signifies that the
 connection to the remote host has been authenticated.
 
 by Exim in conjunction with the &%-MC%& option. It signifies that the
 connection to the remote host has been authenticated.
 

+.vitem &%-MCD%&
+.oindex "&%-MCD%&"
+This option is not intended for use by external callers. It is used internally
+by Exim in conjunction with the &%-MC%& option. It signifies that the
+remote host supports the ESMTP &_DSN_& extension.
+

 .vitem &%-MCP%&
 .oindex "&%-MCP%&"
 This option is not intended for use by external callers. It is used internally
 .vitem &%-MCP%&
 .oindex "&%-MCP%&"
 This option is not intended for use by external callers. It is used internally


@@ -4640,6 +4650,13 @@ this option.
 .oindex "&%-X%&"
 This option is interpreted by Sendmail to cause debug information to be sent
 to the named file.  It is ignored by Exim.
 .oindex "&%-X%&"
 This option is interpreted by Sendmail to cause debug information to be sent
 to the named file.  It is ignored by Exim.

+
+.vitem &%-z%&&~<&'log-line'&>
+.oindex "&%-z%&"
+This option writes its argument to Exim's logfile.
+Use is restricted to administrators; the intent is for operational notes.
+Quotes should be used to maintain a multi-word item as a single argument,
+under most shells.

 .endlist
 
 .ecindex IIDclo1
 .endlist
 
 .ecindex IIDclo1


@@ -4790,8 +4807,8 @@ help with this. See the comments in &_src/EDITME_& for details.
 Exim's configuration file is divided into a number of different parts. General
 option settings must always appear at the start of the file. The other parts
 are all optional, and may appear in any order. Each part other than the first
 Exim's configuration file is divided into a number of different parts. General
 option settings must always appear at the start of the file. The other parts
 are all optional, and may appear in any order. Each part other than the first

-is introduced by the word &"begin"& followed by the name of the part. The
-optional parts are:
+is introduced by the word &"begin"& followed by at least one literal
+space, and the name of the part. The optional parts are:

 
 .ilist
 &'ACL'&: Access control lists for controlling incoming SMTP mail (see chapter
 
 .ilist
 &'ACL'&: Access control lists for controlling incoming SMTP mail (see chapter


@@ -4996,7 +5013,8 @@ message_size_limit = 50M
 message_size_limit = 100M
 .endif
 .endd
 message_size_limit = 100M
 .endif
 .endd

-sets a message size limit of 50M if the macro &`AAA`& is defined, and 100M
+sets a message size limit of 50M if the macro &`AAA`& is defined
+(or &`A`& or &`AA`&), and 100M

 otherwise. If there is more than one macro named on the line, the condition
 is true if any of them are defined. That is, it is an &"or"& condition. To
 obtain an &"and"& condition, you need to use nested &`.ifdef`&s.
 otherwise. If there is more than one macro named on the line, the condition
 is true if any of them are defined. That is, it is an &"or"& condition. To
 obtain an &"and"& condition, you need to use nested &`.ifdef`&s.


@@ -5218,7 +5236,7 @@ list items, it is not ignored when parsing the list. The space after the first
 colon in the example above is necessary. If it were not there, the list would
 be interpreted as the two items 127.0.0.1:: and 1.
 
 colon in the example above is necessary. If it were not there, the list would
 be interpreted as the two items 127.0.0.1:: and 1.
 

-.section "Changing list separators" "SECID53"
+.section "Changing list separators" "SECTlistsepchange"

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


@@ -5584,6 +5602,13 @@ find that they send unqualified addresses. The two commented-out options:
 show how you can specify hosts that are permitted to send unqualified sender
 and recipient addresses, respectively.
 
 show how you can specify hosts that are permitted to send unqualified sender
 and recipient addresses, respectively.
 

+The &%log_selector%& option is used to increase the detail of logging
+over the default:
+.code
+log_selector = +smtp_protocol_error +smtp_syntax_error \
+               +tls_certificate_verified
+.endd
+

 The &%percent_hack_domains%& option is also commented out:
 .code
 # percent_hack_domains =
 The &%percent_hack_domains%& option is also commented out:
 .code
 # percent_hack_domains =


@@ -6042,8 +6067,8 @@ address_pipe:
 .endd
 This transport is used for handling deliveries to pipes that are generated by
 redirection (aliasing or users' &_.forward_& files). The &%return_output%&
 .endd
 This transport is used for handling deliveries to pipes that are generated by
 redirection (aliasing or users' &_.forward_& files). The &%return_output%&

-option specifies that any output generated by the pipe is to be returned to the
-sender.
+option specifies that any output on stdout or stderr generated by the pipe is to
+be returned to the sender.

 .code
 address_file:
   driver = appendfile
 .code
 address_file:
   driver = appendfile


@@ -6225,12 +6250,14 @@ cause parts of the string to be replaced by data that is obtained from the
 lookup. Lookups of this type are conditional expansion items. Different results
 can be defined for the cases of lookup success and failure. See chapter
 &<<CHAPexpand>>&, where string expansions are described in detail.
 lookup. Lookups of this type are conditional expansion items. Different results
 can be defined for the cases of lookup success and failure. See chapter
 &<<CHAPexpand>>&, where string expansions are described in detail.

+The key for the lookup is specified as part of the string expansion.

 .next
 Lists of domains, hosts, and email addresses can contain lookup requests as a
 way of avoiding excessively long linear lists. In this case, the data that is
 returned by the lookup is often (but not always) discarded; whether the lookup
 succeeds or fails is what really counts. These kinds of list are described in
 chapter &<<CHAPdomhosaddlists>>&.
 .next
 Lists of domains, hosts, and email addresses can contain lookup requests as a
 way of avoiding excessively long linear lists. In this case, the data that is
 returned by the lookup is often (but not always) discarded; whether the lookup
 succeeds or fails is what really counts. These kinds of list are described in
 chapter &<<CHAPdomhosaddlists>>&.

+The key for the lookup is given by the context in which the list is expanded.

 .endlist
 
 String expansions, lists, and lookups interact with each other in such a way
 .endlist
 
 String expansions, lists, and lookups interact with each other in such a way


@@ -6864,19 +6891,11 @@ is used on its own as the result. If the lookup does not succeed, the
 &`fail`& keyword causes a &'forced expansion failure'& &-- see section
 &<<SECTforexpfai>>& for an explanation of what this means.
 
 &`fail`& keyword causes a &'forced expansion failure'& &-- see section
 &<<SECTforexpfai>>& for an explanation of what this means.
 

-The supported DNS record types are A, CNAME, MX, NS, PTR, SPF, SRV, TLSA and TXT,
-and, when Exim is compiled with IPv6 support, AAAA (and A6 if that is also
-configured). If no type is given, TXT is assumed. When the type is PTR,
-the data can be an IP address, written as normal; inversion and the addition of
-&%in-addr.arpa%& or &%ip6.arpa%& happens automatically. For example:
-.code
-${lookup dnsdb{ptr=192.168.4.5}{$value}fail}
-.endd
-If the data for a PTR record is not a syntactically valid IP address, it is not
-altered and nothing is added.
+The supported DNS record types are A, CNAME, MX, NS, PTR, SOA, SPF, SRV, TLSA
+and TXT, and, when Exim is compiled with IPv6 support, AAAA.
+If no type is given, TXT is assumed.

 
 

-For any record type, if multiple records are found (or, for A6 lookups, if a
-single record leads to multiple addresses), the data is returned as a
+For any record type, if multiple records are found, the data is returned as a

 concatenation, with newline as the default separator. The order, of course,
 depends on the DNS resolver. You can specify a different separator character
 between multiple records by putting a right angle-bracket followed immediately
 concatenation, with newline as the default separator. The order, of course,
 depends on the DNS resolver. You can specify a different separator character
 between multiple records by putting a right angle-bracket followed immediately


@@ -6886,21 +6905,33 @@ ${lookup dnsdb{>: a=host1.example}}
 .endd
 It is permitted to specify a space as the separator character. Further
 white space is ignored.
 .endd
 It is permitted to specify a space as the separator character. Further
 white space is ignored.

+For lookup types that return multiple fields per record,
+an alternate field separator can be specified using a comma after the main
+separator character, followed immediately by the field separator.
+
+.cindex "PTR record" "in &(dnsdb)& lookup"
+When the type is PTR,
+the data can be an IP address, written as normal; inversion and the addition of
+&%in-addr.arpa%& or &%ip6.arpa%& happens automatically. For example:
+.code
+${lookup dnsdb{ptr=192.168.4.5}{$value}fail}
+.endd
+If the data for a PTR record is not a syntactically valid IP address, it is not
+altered and nothing is added.

 
 .cindex "MX record" "in &(dnsdb)& lookup"
 .cindex "SRV record" "in &(dnsdb)& lookup"
 For an MX lookup, both the preference value and the host name are returned for
 each record, separated by a space. For an SRV lookup, the priority, weight,
 port, and host name are returned for each record, separated by spaces.
 
 .cindex "MX record" "in &(dnsdb)& lookup"
 .cindex "SRV record" "in &(dnsdb)& lookup"
 For an MX lookup, both the preference value and the host name are returned for
 each record, separated by a space. For an SRV lookup, the priority, weight,
 port, and host name are returned for each record, separated by spaces.

-An alternate field separator can be specified using a comma after the main
-separator character, followed immediately by the field separator.
+The field separator can be modified as above.

 
 .cindex "TXT record" "in &(dnsdb)& lookup"
 .cindex "SPF record" "in &(dnsdb)& lookup"
 For TXT records with multiple items of data, only the first item is returned,
 
 .cindex "TXT record" "in &(dnsdb)& lookup"
 .cindex "SPF record" "in &(dnsdb)& lookup"
 For TXT records with multiple items of data, only the first item is returned,

-unless a separator for them is specified using a comma after the separator
-character followed immediately by the TXT record item separator. To concatenate
-items without a separator, use a semicolon instead. For SPF records the
+unless a field separator is specified.
+To concatenate items without a separator, use a semicolon instead.
+For SPF records the

 default behaviour is to concatenate multiple items without using a separator.
 .code
 ${lookup dnsdb{>\n,: txt=a.b.example}}
 default behaviour is to concatenate multiple items without using a separator.
 .code
 ${lookup dnsdb{>\n,: txt=a.b.example}}


@@ -6910,11 +6941,20 @@ ${lookup dnsdb{spf=example.org}}
 It is permitted to specify a space as the separator character. Further
 white space is ignored.
 
 It is permitted to specify a space as the separator character. Further
 white space is ignored.
 

+.cindex "SOA record" "in &(dnsdb)& lookup"
+For an SOA lookup, while no result is obtained the lookup is redone with
+successively more leading components dropped from the given domain.
+Only the primary-nameserver field is returned unless a field separator is
+specified.
+.code
+${lookup dnsdb{>:,; soa=a.b.example.com}}
+.endd
+

 .section "Dnsdb lookup modifiers" "SECTdnsdb_mod"
 .cindex "dnsdb modifiers"
 .cindex "modifiers" "dnsdb"
 .cindex "options" "dnsdb"
 .section "Dnsdb lookup modifiers" "SECTdnsdb_mod"
 .cindex "dnsdb modifiers"
 .cindex "modifiers" "dnsdb"
 .cindex "options" "dnsdb"

-Modifiers for &(dnsdb)& lookups are givien by optional keywords,
+Modifiers for &(dnsdb)& lookups are given by optional keywords,

 each followed by a comma,
 that may appear before the record type.
 
 each followed by a comma,
 that may appear before the record type.
 


@@ -6949,6 +6989,26 @@ The default is &"never"&.
 
 See also the &$lookup_dnssec_authenticated$& variable.
 
 
 See also the &$lookup_dnssec_authenticated$& variable.
 

+.cindex timeout "dns lookup"
+.cindex "DNS" timeout
+Timeout for the dnsdb lookup can be controlled by a retrans modifier.
+The form is &"retrans_VAL"& where VAL is an Exim time specification
+(e.g. &"5s"&).
+The default value is set by the main configuration option &%dns_retrans%&.
+
+Retries for the dnsdb lookup can be controlled by a retry modifier.
+The form if &"retry_VAL"& where VAL is an integer.
+The default count is set by the main configuration option &%dns_retry%&.
+
+.new
+.cindex cacheing "of dns lookup"
+.cindex TTL "of dns lookup"
+.cindex DNS TTL
+Dnsdb lookup results are cached within a single process (and its children).
+The cache entry lifetime is limited to the smallest time-to-live (TTL)
+value of the set of returned DNS records.
+.wen
+

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


@@ -6998,7 +7058,7 @@ The authorization code can be &"Y"& for yes, &"N"& for no, &"X"& for explicit
 authorization required but absent, or &"?"& for unknown.
 
 .cindex "A+" "in &(dnsdb)& lookup"
 authorization required but absent, or &"?"& for unknown.
 
 .cindex "A+" "in &(dnsdb)& lookup"

-The pseudo-type A+ performs an A6 lookup (if configured) followed by an AAAA
+The pseudo-type A+ performs an AAAA

 and then an A lookup.  All results are returned; defer processing
 (see below) is handled separately for each lookup.  Example:
 .code
 and then an A lookup.  All results are returned; defer processing
 (see below) is handled separately for each lookup.  Example:
 .code


@@ -7254,6 +7314,8 @@ The value of the DEREFERENCE parameter must be one of the words &"never"&,
 must be &"follow"& (the default) or &"nofollow"&. The latter stops the LDAP
 library from trying to follow referrals issued by the LDAP server.
 
 must be &"follow"& (the default) or &"nofollow"&. The latter stops the LDAP
 library from trying to follow referrals issued by the LDAP server.
 

+.cindex LDAP timeout
+.cindex timeout "LDAP lookup"

 The name CONNECT is an obsolete name for NETTIME, retained for
 backwards compatibility. This timeout (specified as a number of seconds) is
 enforced from the client end for operations that can be carried out over a
 The name CONNECT is an obsolete name for NETTIME, retained for
 backwards compatibility. This timeout (specified as a number of seconds) is
 enforced from the client end for operations that can be carried out over a


@@ -7268,7 +7330,7 @@ The TIME parameter (also a number of seconds) is passed to the server to
 set a server-side limit on the time taken to complete a search.
 
 The SERVERS parameter allows you to specify an alternate list of ldap servers
 set a server-side limit on the time taken to complete a search.
 
 The SERVERS parameter allows you to specify an alternate list of ldap servers

-to use for an individual lookup.  The global ldap_servers option provides a
+to use for an individual lookup.  The global &%ldap_default_servers%& option provides a

 default list of ldap servers, and a single lookup can specify a single ldap
 server to use.  But when you need to do a lookup with a list of servers that is
 different than the default list (maybe different order, maybe a completely
 default list of ldap servers, and a single lookup can specify a single ldap
 server to use.  But when you need to do a lookup with a list of servers that is
 different than the default list (maybe different order, maybe a completely


@@ -7328,7 +7390,7 @@ SMTP authentication. See the &%ldapauth%& expansion string condition in chapter
 The &(ldapdn)& lookup type returns the Distinguished Name from a single entry
 as a sequence of values, for example
 .code
 The &(ldapdn)& lookup type returns the Distinguished Name from a single entry
 as a sequence of values, for example
 .code

-cn=manager, o=University of Cambridge, c=UK
+cn=manager,o=University of Cambridge,c=UK

 .endd
 The &(ldap)& lookup type generates an error if more than one entry matches the
 search filter, whereas &(ldapm)& permits this case, and inserts a newline in
 .endd
 The &(ldap)& lookup type generates an error if more than one entry matches the
 search filter, whereas &(ldapm)& permits this case, and inserts a newline in


@@ -7339,7 +7401,8 @@ directory.
 
 In the common case where you specify a single attribute in your LDAP query, the
 result is not quoted, and does not contain the attribute name. If the attribute
 
 In the common case where you specify a single attribute in your LDAP query, the
 result is not quoted, and does not contain the attribute name. If the attribute

-has multiple values, they are separated by commas.
+has multiple values, they are separated by commas. Any comma that is
+part of an attribute's value is doubled.

 
 If you specify multiple attributes, the result contains space-separated, quoted
 strings, each preceded by the attribute name and an equals sign. Within the
 
 If you specify multiple attributes, the result contains space-separated, quoted
 strings, each preceded by the attribute name and an equals sign. Within the


@@ -7354,7 +7417,9 @@ same as specifying all of an entry's attributes.
 Here are some examples of the output format. The first line of each pair is an
 LDAP query, and the second is the data that is returned. The attribute called
 &%attr1%& has two values, one of them with an embedded comma, whereas
 Here are some examples of the output format. The first line of each pair is an
 LDAP query, and the second is the data that is returned. The attribute called
 &%attr1%& has two values, one of them with an embedded comma, whereas

-&%attr2%& has only one value:
+&%attr2%& has only one value. Both attributes are derived from &%attr%&
+(they have SUP &%attr%& in their schema definitions).
+

 .code
 ldap:///o=base?attr1?sub?(uid=fred)
 value1.1,value1,,2
 .code
 ldap:///o=base?attr1?sub?(uid=fred)
 value1.1,value1,,2


@@ -7362,6 +7427,9 @@ value1.1,value1,,2
 ldap:///o=base?attr2?sub?(uid=fred)
 value two
 
 ldap:///o=base?attr2?sub?(uid=fred)
 value two
 

+ldap:///o=base?attr?sub?(uid=fred)
+value1.1,value1,,2,value two
+

 ldap:///o=base?attr1,attr2?sub?(uid=fred)
 attr1="value1.1,value1,,2" attr2="value two"
 
 ldap:///o=base?attr1,attr2?sub?(uid=fred)
 attr1="value1.1,value1,,2" attr2="value two"
 


@@ -7484,13 +7552,12 @@ a query is successfully processed. The result of a query may be that no data is
 found, but that is still a successful query. In other words, the list of
 servers provides a backup facility, not a list of different places to look.
 
 found, but that is still a successful query. In other words, the list of
 servers provides a backup facility, not a list of different places to look.
 

+.new

 The &%quote_mysql%&, &%quote_pgsql%&, and &%quote_oracle%& expansion operators
 convert newline, tab, carriage return, and backspace to \n, \t, \r, and \b
 respectively, and the characters single-quote, double-quote, and backslash
 The &%quote_mysql%&, &%quote_pgsql%&, and &%quote_oracle%& expansion operators
 convert newline, tab, carriage return, and backspace to \n, \t, \r, and \b
 respectively, and the characters single-quote, double-quote, and backslash

-itself are escaped with backslashes. The &%quote_pgsql%& expansion operator, in
-addition, escapes the percent and underscore characters. This cannot be done
-for MySQL because these escapes are not recognized in contexts where these
-characters are not special.
+itself are escaped with backslashes.
+.wen

 
 .section "Specifying the server in the query" "SECTspeserque"
 For MySQL and PostgreSQL lookups (but not currently for Oracle and InterBase),
 
 .section "Specifying the server in the query" "SECTspeserque"
 For MySQL and PostgreSQL lookups (but not currently for Oracle and InterBase),


@@ -7536,13 +7603,17 @@ ${lookup pgsql{servers=master/db/name/pw; UPDATE ...} }
 .section "Special MySQL features" "SECID73"
 For MySQL, an empty host name or the use of &"localhost"& in &%mysql_servers%&
 causes a connection to the server on the local host by means of a Unix domain
 .section "Special MySQL features" "SECID73"
 For MySQL, an empty host name or the use of &"localhost"& in &%mysql_servers%&
 causes a connection to the server on the local host by means of a Unix domain

-socket. An alternate socket can be specified in parentheses. The full syntax of
-each item in &%mysql_servers%& is:
+socket. An alternate socket can be specified in parentheses.
+.new
+An option group name for MySQL option files can be specified in square brackets;
+the default value is &"exim"&.
+.wen
+The full syntax of each item in &%mysql_servers%& is:

 .display
 .display

-<&'hostname'&>::<&'port'&>(<&'socket name'&>)/<&'database'&>/&&&
-  <&'user'&>/<&'password'&>
+<&'hostname'&>::<&'port'&>(<&'socket name'&>)[<&'option group'&>]/&&&
+  <&'database'&>/<&'user'&>/<&'password'&>

 .endd
 .endd

-Any of the three sub-parts of the first field can be omitted. For normal use on
+Any of the four sub-parts of the first field can be omitted. For normal use on

 the local host it can be left blank or set to just &"localhost"&.
 
 No database need be supplied &-- but if it is absent here, it must be given in
 the local host it can be left blank or set to just &"localhost"&.
 
 No database need be supplied &-- but if it is absent here, it must be given in


@@ -7594,6 +7665,8 @@ domainlist relay_to_domains = sqlite;/some/thing/sqlitedb \
 The only character affected by the &%quote_sqlite%& operator is a single
 quote, which it doubles.
 
 The only character affected by the &%quote_sqlite%& operator is a single
 quote, which it doubles.
 

+.cindex timeout SQLite
+.cindex sqlite "lookup timeout"

 The SQLite library handles multiple simultaneous accesses to the database
 internally. Multiple readers are permitted, but only one process can
 update at once. Attempts to access the database while it is being updated
 The SQLite library handles multiple simultaneous accesses to the database
 internally. Multiple readers are permitted, but only one process can
 update at once. Attempts to access the database while it is being updated


@@ -7623,6 +7696,10 @@ host, email address, or local part, respectively. In the sections below, the
 different types of pattern for each case are described, but first we cover some
 general facilities that apply to all four kinds of list.
 
 different types of pattern for each case are described, but first we cover some
 general facilities that apply to all four kinds of list.
 

+Note that other parts of Exim use a &'string list'& which does not
+support all the complexity available in
+domain, host, address and local part lists.
+

 
 
 .section "Expansion of lists" "SECID75"
 
 
 .section "Expansion of lists" "SECID75"


@@ -8405,7 +8482,7 @@ this section.
 .cindex "&`+ignore_defer`&"
 A temporary DNS lookup failure normally causes a defer action (except when
 &%dns_again_means_nonexist%& converts it into a permanent error). However,
 .cindex "&`+ignore_defer`&"
 A temporary DNS lookup failure normally causes a defer action (except when
 &%dns_again_means_nonexist%& converts it into a permanent error). However,

-host lists can include &`+ignore_defer`& and &`+include_defer`&, analagous to
+host lists can include &`+ignore_defer`& and &`+include_defer`&, analogous to

 &`+ignore_unknown`& and &`+include_unknown`&, as described in the previous
 section. These options should be used with care, probably only in non-critical
 host lists such as whitelists.
 &`+ignore_unknown`& and &`+include_unknown`&, as described in the previous
 section. These options should be used with care, probably only in non-critical
 host lists such as whitelists.


@@ -8896,7 +8973,7 @@ If the ACL returns defer the result is a forced-fail.  Otherwise the expansion f
 .cindex "&%certextract%&" "certificate fields"
 .cindex "certificate" "extracting fields"
 The <&'certificate'&> must be a variable of type certificate.
 .cindex "&%certextract%&" "certificate fields"
 .cindex "certificate" "extracting fields"
 The <&'certificate'&> must be a variable of type certificate.

-The field name is expanded and used to retrive the relevant field from
+The field name is expanded and used to retrieve the relevant field from

 the certificate.  Supported fields are:
 .display
 &`version        `&
 the certificate.  Supported fields are:
 .display
 &`version        `&


@@ -8927,11 +9004,11 @@ The field selectors marked as "RFC4514" above
 output a Distinguished Name string which is
 not quite
 parseable by Exim as a comma-separated tagged list
 output a Distinguished Name string which is
 not quite
 parseable by Exim as a comma-separated tagged list

-(the exceptions being elements containin commas).
+(the exceptions being elements containing commas).

 RDN elements of a single type may be selected by
 a modifier of the type label; if so the expansion
 result is a list (newline-separated by default).
 RDN elements of a single type may be selected by
 a modifier of the type label; if so the expansion
 result is a list (newline-separated by default).

-The separator may be changed by another modifer of
+The separator may be changed by another modifier of

 a right angle-bracket followed immediately by the new separator.
 Recognised RDN type labels include "CN", "O", "OU" and "DC".
 
 a right angle-bracket followed immediately by the new separator.
 Recognised RDN type labels include "CN", "O", "OU" and "DC".
 


@@ -8951,7 +9028,7 @@ The field selectors marked as "tagged" above
 prefix each list element with a type string and an equals sign.
 Elements of only one type may be selected by a modifier
 which is one of "dns", "uri" or "mail";
 prefix each list element with a type string and an equals sign.
 Elements of only one type may be selected by a modifier
 which is one of "dns", "uri" or "mail";

-if so the elenment tags are omitted.
+if so the element tags are omitted.

 
 If not otherwise noted field values are presented in human-readable form.
 
 
 If not otherwise noted field values are presented in human-readable form.
 


@@ -8993,6 +9070,30 @@ When compiling a function that is to be used in this way with gcc,
 you need to add &%-shared%& to the gcc command. Also, in the Exim build-time
 configuration, you must add &%-export-dynamic%& to EXTRALIBS.
 
 you need to add &%-shared%& to the gcc command. Also, in the Exim build-time
 configuration, you must add &%-export-dynamic%& to EXTRALIBS.
 

+
+.vitem "&*${env{*&<&'key'&>&*}{*&<&'string1'&>&*}{*&<&'string2'&>&*}}*&"
+.cindex "expansion" "extracting value from environment"
+.cindex "environment" "value from"
+The key is first expanded separately, and leading and trailing white space
+removed.
+This is then searched for as a name in the environment.
+If a variable is found then its value is placed in &$value$&
+and <&'string1'&> is expanded, otherwise <&'string2'&> is expanded.
+
+Instead of {<&'string2'&>} the word &"fail"& (not in curly brackets) can
+appear, for example:
+.code
+${env{USER}{$value} fail }
+.endd
+This forces an expansion failure (see section &<<SECTforexpfai>>&);
+{<&'string1'&>} must be present for &"fail"& to be recognized.
+
+If {<&'string2'&>} is omitted an empty string is substituted on
+search failure.
+If {<&'string1'&>} is omitted the search result is substituted on
+search success.
+
+

 .vitem "&*${extract{*&<&'key'&>&*}{*&<&'string1'&>&*}{*&<&'string2'&>&*}&&&
        {*&<&'string3'&>&*}}*&"
 .cindex "expansion" "extracting substrings by key"
 .vitem "&*${extract{*&<&'key'&>&*}{*&<&'string1'&>&*}{*&<&'string2'&>&*}&&&
        {*&<&'string3'&>&*}}*&"
 .cindex "expansion" "extracting substrings by key"


@@ -9192,10 +9293,11 @@ by earlier ACLs are visible.
 Upper case and lower case letters are synonymous in header names. If the
 following character is white space, the terminating colon may be omitted, but
 this is not recommended, because you may then forget it when it is needed. When
 Upper case and lower case letters are synonymous in header names. If the
 following character is white space, the terminating colon may be omitted, but
 this is not recommended, because you may then forget it when it is needed. When

-white space terminates the header name, it is included in the expanded string.
-If the message does not contain the given header, the expansion item is
-replaced by an empty string. (See the &%def%& condition in section
-&<<SECTexpcond>>& for a means of testing for the existence of a header.)
+white space terminates the header name, this white space is included in the
+expanded string.  If the message does not contain the given header, the
+expansion item is replaced by an empty string. (See the &%def%& condition in
+section &<<SECTexpcond>>& for a means of testing for the existence of a
+header.)

 
 If there is more than one header with the same name, they are all concatenated
 to form the substitution string, up to a maximum length of 64K. Unless
 
 If there is more than one header with the same name, they are all concatenated
 to form the substitution string, up to a maximum length of 64K. Unless


@@ -9317,7 +9419,7 @@ yields &"42"&, and
 .code
 ${listextract{-3}{<, x,42,99,& Mailer,,/bin/bash}{result: $value}}
 .endd
 .code
 ${listextract{-3}{<, x,42,99,& Mailer,,/bin/bash}{result: $value}}
 .endd

-yields &"result: 99"&.
+yields &"result: 42"&.

 
 If {<&'string3'&>} is omitted, an empty string is used for string3.
 If {<&'string2'&>} is also omitted, the value that was
 
 If {<&'string3'&>} is omitted, an empty string is used for string3.
 If {<&'string2'&>} is also omitted, the value that was


@@ -9698,8 +9800,9 @@ the regular expression from string expansion.
 
 
 .vitem &*${sort{*&<&'string'&>&*}{*&<&'comparator'&>&*}{*&<&'extractor'&>&*}}*&
 
 
 .vitem &*${sort{*&<&'string'&>&*}{*&<&'comparator'&>&*}{*&<&'extractor'&>&*}}*&

-.cindex sorting a list
+.cindex sorting "a list"

 .cindex list sorting
 .cindex list sorting

+.cindex expansion "list sorting"

 After expansion, <&'string'&> is interpreted as a list, colon-separated by
 default, but the separator can be changed in the usual way.
 The <&'comparator'&> argument is interpreted as the operator
 After expansion, <&'string'&> is interpreted as a list, colon-separated by
 default, but the separator can be changed in the usual way.
 The <&'comparator'&> argument is interpreted as the operator


@@ -9721,7 +9824,7 @@ ${sort{3:2:1:4}{<}{$item}}
 .endd
 sorts a list of numbers, and
 .code
 .endd
 sorts a list of numbers, and
 .code

-${sort {$lookup dnsdb{>:,,mx=example.com}} {<} {${listextract{1}{<,$item}}}}
+${sort {${lookup dnsdb{>:,,mx=example.com}}} {<} {${listextract{1}{<,$item}}}}

 .endd
 will sort an MX lookup into priority order.
 
 .endd
 will sort an MX lookup into priority order.
 


@@ -9841,7 +9944,7 @@ processing lists.
 To clarify "list of addresses in RFC 2822 format" mentioned above, Exim follows
 a strict interpretation of header line formatting.  Exim parses the bare,
 unquoted portion of an email address and if it finds a comma, treats it as an
 To clarify "list of addresses in RFC 2822 format" mentioned above, Exim follows
 a strict interpretation of header line formatting.  Exim parses the bare,
 unquoted portion of an email address and if it finds a comma, treats it as an

-email address seperator. For the example header line:
+email address separator. For the example header line:

 .code
 From: =?iso-8859-2?Q?Last=2C_First?= <user@example.com>
 .endd
 .code
 From: =?iso-8859-2?Q?Last=2C_First?= <user@example.com>
 .endd


@@ -10025,6 +10128,27 @@ as is, and other byte values are converted to &`\xNN`&, for example a
 byte value 127 is converted to &`\x7f`&.
 
 
 byte value 127 is converted to &`\x7f`&.
 
 

+.new
+.vitem &*${ipv6denorm:*&<&'string'&>&*}*&
+.cindex "&%ipv6denorm%& expansion item"
+.cindex "IP address" normalisation
+This expands an IPv6 address to a full eight-element colon-separated set
+of hex digits including leading zeroes.
+A trailing ipv4-style dotted-decimal set is converted to hex.
+Pure IPv4 addresses are converted to IPv4-mapped IPv6.
+
+.vitem &*${ipv6norm:*&<&'string'&>&*}*&
+.cindex "&%ipv6norm%& expansion item"
+.cindex "IP address" normalisation
+.cindex "IP address" "canonical form"
+This converts an IPv6 address to canonical form.
+Leading zeroes of groups are omitted, and the longest
+set of zero-valued groups is replaced with a double colon.
+A trailing ipv4-style dotted-decimal set is converted to hex.
+Pure IPv4 addresses are converted to IPv4-mapped IPv6.
+.wen
+
+

 .vitem &*${lc:*&<&'string'&>&*}*&
 .cindex "case forcing in strings"
 .cindex "string" "case forcing"
 .vitem &*${lc:*&<&'string'&>&*}*&
 .cindex "case forcing in strings"
 .cindex "string" "case forcing"


@@ -10187,7 +10311,7 @@ random().
 .vitem &*${reverse_ip:*&<&'ipaddr'&>&*}*&
 .cindex "expansion" "IP address"
 This operator reverses an IP address; for IPv4 addresses, the result is in
 .vitem &*${reverse_ip:*&<&'ipaddr'&>&*}*&
 .cindex "expansion" "IP address"
 This operator reverses an IP address; for IPv4 addresses, the result is in

-dotted-quad decimal form, while for IPv6 addreses the result is in
+dotted-quad decimal form, while for IPv6 addresses the result is in

 dotted-nibble hexadecimal form.  In both cases, this is the "natural" form
 for DNS.  For example,
 .code
 dotted-nibble hexadecimal form.  In both cases, this is the "natural" form
 for DNS.  For example,
 .code


@@ -10208,7 +10332,7 @@ f.7.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
 This operator encodes text according to the rules of RFC 2047. This is an
 encoding that is used in header lines to encode non-ASCII characters. It is
 assumed that the input string is in the encoding specified by the
 This operator encodes text according to the rules of RFC 2047. This is an
 encoding that is used in header lines to encode non-ASCII characters. It is
 assumed that the input string is in the encoding specified by the

-&%headers_charset%& option, which defaults to ISO-8859-1. If the string
+&%headers_charset%& option, which gets its default at build time. If the string

 contains only characters in the range 33&--126, and no instances of the
 characters
 .code
 contains only characters in the range 33&--126, and no instances of the
 characters
 .code


@@ -11036,7 +11160,8 @@ support for TLS or the content scanning extension.
 When a &%match%& expansion condition succeeds, these variables contain the
 captured substrings identified by the regular expression during subsequent
 processing of the success string of the containing &%if%& expansion item.
 When a &%match%& expansion condition succeeds, these variables contain the
 captured substrings identified by the regular expression during subsequent
 processing of the success string of the containing &%if%& expansion item.

-However, they do not retain their values afterwards; in fact, their previous
+In the expansion condition case
+they do not retain their values afterwards; in fact, their previous

 values are restored at the end of processing an &%if%& item. The numerical
 variables may also be set externally by some other matching process which
 precedes the expansion of the string. For example, the commands available in
 values are restored at the end of processing an &%if%& item. The numerical
 variables may also be set externally by some other matching process which
 precedes the expansion of the string. For example, the commands available in


@@ -11244,9 +11369,10 @@ not the same as the user id of the originator of a message (see
 &$originator_uid$&). If Exim re-execs itself, this variable in the new
 incarnation normally contains the Exim uid.
 
 &$originator_uid$&). If Exim re-execs itself, this variable in the new
 incarnation normally contains the Exim uid.
 

-.vitem &$compile_date$&
-.vindex "&$compile_date$&"
-The date on which the Exim binary was compiled.
+.vitem &$callout_address$&
+.vindex "&$callout_address$&"
+After a callout for verification, spamd or malware daemon service, the
+address that was connected to.

 
 .vitem &$compile_number$&
 .vindex "&$compile_number$&"
 
 .vitem &$compile_number$&
 .vindex "&$compile_number$&"


@@ -11254,6 +11380,17 @@ The building process for Exim keeps a count of the number
 of times it has been compiled. This serves to distinguish different
 compilations of the same version of the program.
 
 of times it has been compiled. This serves to distinguish different
 compilations of the same version of the program.
 

+.vitem &$config_dir$&
+.vindex "&$config_dir$&"
+The directory name of the main configuration file. That is, the content of
+&$config_file$& with the last component stripped. The value does not
+contain the trailing slash. If &$config_file$& does not contain a slash,
+&$config_dir$& is ".".
+
+.vitem &$config_file$&
+.vindex "&$config_file$&"
+The name of the main configuration file Exim is using.
+

 .vitem &$demime_errorlevel$&
 .vindex "&$demime_errorlevel$&"
 This variable is available when Exim is compiled with
 .vitem &$demime_errorlevel$&
 .vindex "&$demime_errorlevel$&"
 This variable is available when Exim is compiled with


@@ -11266,6 +11403,35 @@ This variable is available when Exim is compiled with the
 content-scanning extension and the obsolete &%demime%& condition. For details,
 see section &<<SECTdemimecond>>&.
 
 content-scanning extension and the obsolete &%demime%& condition. For details,
 see section &<<SECTdemimecond>>&.
 

+.vitem &$dkim_cur_signer$& &&&
+       &$dkim_verify_status$& &&&
+       &$dkim_verify_reason$& &&&
+       &$dkim_domain$& &&&
+       &$dkim_identity$& &&&
+       &$dkim_selector$& &&&
+       &$dkim_algo$& &&&
+       &$dkim_canon_body$& &&&
+       &$dkim_canon_headers$& &&&
+       &$dkim_copiedheaders$& &&&
+       &$dkim_bodylength$& &&&
+       &$dkim_created$& &&&
+       &$dkim_expires$& &&&
+       &$dkim_headernames$& &&&
+       &$dkim_key_testing$& &&&
+       &$dkim_key_nosubdomains$& &&&
+       &$dkim_key_srvtype$& &&&
+       &$dkim_key_granularity$& &&&
+       &$dkim_key_notes$& &&&
+       &$dkim_key_length$&
+These variables are only available within the DKIM ACL.
+For details see chapter &<<CHAPdkim>>&.
+
+.vitem &$dkim_signers$&
+.vindex &$dkim_signers$&
+When a message has been received this variable contains
+a colon-separated list of signer domains and identities for the message.
+For details see chapter &<<CHAPdkim>>&.
+

 .vitem &$dnslist_domain$& &&&
        &$dnslist_matched$& &&&
        &$dnslist_text$& &&&
 .vitem &$dnslist_domain$& &&&
        &$dnslist_matched$& &&&
        &$dnslist_text$& &&&


@@ -11361,6 +11527,13 @@ This variable contains the path to the Exim binary.
 .vindex "&$exim_uid$&"
 This variable contains the numerical value of the Exim user id.
 
 .vindex "&$exim_uid$&"
 This variable contains the numerical value of the Exim user id.
 

+.vitem &$exim_version$&
+.vindex "&$exim_version$&"
+This variable contains the version string of the Exim build.
+The first character is a major version number, currently 4.
+Then after a dot, the next group of digits is a minor version number.
+There may be other characters following the minor version.
+

 .vitem &$found_extension$&
 .vindex "&$found_extension$&"
 This variable is available when Exim is compiled with the
 .vitem &$found_extension$&
 .vindex "&$found_extension$&"
 This variable is available when Exim is compiled with the


@@ -11620,9 +11793,13 @@ the space value is -1. See also the &%check_log_space%& option.
 .vindex "&$lookup_dnssec_authenticated$&"
 This variable is set after a DNS lookup done by
 a dnsdb lookup expansion, dnslookup router or smtp transport.
 .vindex "&$lookup_dnssec_authenticated$&"
 This variable is set after a DNS lookup done by
 a dnsdb lookup expansion, dnslookup router or smtp transport.

+.cindex "DNS" "DNSSEC"

 It will be empty if &(DNSSEC)& was not requested,
 &"no"& if the result was not labelled as authenticated data
 and &"yes"& if it was.
 It will be empty if &(DNSSEC)& was not requested,
 &"no"& if the result was not labelled as authenticated data
 and &"yes"& if it was.

+Results that are labelled as authoritative answer that match
+the &%dns_trust_aa%& configuration variable count also
+as authenticated data.

 
 .vitem &$mailstore_basename$&
 .vindex "&$mailstore_basename$&"
 
 .vitem &$mailstore_basename$&
 .vindex "&$mailstore_basename$&"


@@ -11855,6 +12032,24 @@ a single-component name, Exim calls &[gethostbyname()]& (or
 qualified host name. See also &$smtp_active_hostname$&.
 
 
 qualified host name. See also &$smtp_active_hostname$&.
 
 

+.new
+.vitem &$proxy_host_address$& &&&
+       &$proxy_host_port$& &&&
+       &$proxy_target_address$& &&&
+       &$proxy_target_port$& &&&
+       &$proxy_session$&
+These variables are only available when built with Proxy Protocol
+or Socks5 support
+For details see chapter &<<SECTproxyInbound>>&.
+.wen
+
+.new
+.vitem &$prdr_requested$&
+.cindex "PRDR" "variable for"
+This variable is set to &"yes"& if PRDR was requested by the client for the
+current message, otherwise &"no"&.
+.wen
+

 .vitem &$prvscheck_address$&
 This variable is used in conjunction with the &%prvscheck%& expansion item,
 which is described in sections &<<SECTexpansionitems>>& and
 .vitem &$prvscheck_address$&
 This variable is used in conjunction with the &%prvscheck%& expansion item,
 which is described in sections &<<SECTexpansionitems>>& and


@@ -12033,6 +12228,12 @@ increases for each accepted recipient. It can be referenced in an ACL.
 This variable is set to contain the matching regular expression after a
 &%regex%& ACL condition has matched (see section &<<SECTscanregex>>&).
 
 This variable is set to contain the matching regular expression after a
 &%regex%& ACL condition has matched (see section &<<SECTscanregex>>&).
 

+.vitem "&$regex1$&, &$regex2$&, etc"
+.cindex "regex submatch variables (&$1regex$& &$2regex$& etc)"
+When a &%regex%& or &%mime_regex%& ACL condition succeeds,
+these variables contain the
+captured substrings identified by the regular expression.
+

 
 .vitem &$reply_address$&
 .vindex "&$reply_address$&"
 
 .vitem &$reply_address$&
 .vindex "&$reply_address$&"


@@ -12137,6 +12338,12 @@ verification either failed or was not requested. A host name in parentheses is
 the argument of a HELO or EHLO command. This is omitted if it is identical to
 the verified host name or to the host's IP address in square brackets.
 
 the argument of a HELO or EHLO command. This is omitted if it is identical to
 the verified host name or to the host's IP address in square brackets.
 

+.vitem &$sender_helo_dnssec$&
+.vindex "&$sender_helo_dnssec$&"
+This boolean variable is true if a successful HELO verification was
+.cindex "DNS" "DNSSEC"
+done using DNS information the resolver library stated was authenticated data.
+

 .vitem &$sender_helo_name$&
 .vindex "&$sender_helo_name$&"
 When a message is received from a remote host that has issued a HELO or EHLO
 .vitem &$sender_helo_name$&
 .vindex "&$sender_helo_name$&"
 When a message is received from a remote host that has issued a HELO or EHLO


@@ -12162,9 +12369,11 @@ received. It is empty if there was no successful authentication. See also
 If an attempt to populate &$sender_host_name$& has been made
 (by reference, &%hosts_lookup%& or
 otherwise) then this boolean will have been set true if, and only if, the
 If an attempt to populate &$sender_host_name$& has been made
 (by reference, &%hosts_lookup%& or
 otherwise) then this boolean will have been set true if, and only if, the

-resolver library states that the reverse DNS was authenticated data.  At all
+resolver library states that both
+the reverse and forward DNS were authenticated data.  At all

 other times, this variable is false.
 
 other times, this variable is false.
 

+.cindex "DNS" "DNSSEC"

 It is likely that you will need to coerce DNSSEC support on in the resolver
 library, by setting:
 .code
 It is likely that you will need to coerce DNSSEC support on in the resolver
 library, by setting:
 .code


@@ -12172,10 +12381,7 @@ dns_dnssec_ok = 1
 .endd
 
 Exim does not perform DNSSEC validation itself, instead leaving that to a
 .endd
 
 Exim does not perform DNSSEC validation itself, instead leaving that to a

-validating resolver (eg, unbound, or bind with suitable configuration).
-
-Exim does not (currently) check to see if the forward DNS was also secured
-with DNSSEC, only the reverse DNS.
+validating resolver (e.g. unbound, or bind with suitable configuration).

 
 If you have changed &%host_lookup_order%& so that &`bydns`& is not the first
 mechanism in the list, then this variable will be false.
 
 If you have changed &%host_lookup_order%& so that &`bydns`& is not the first
 mechanism in the list, then this variable will be false.


@@ -12414,6 +12620,8 @@ inbound connection when the message was received.
 It is only useful as the argument of a
 &%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator,
 or a &%def%& condition.
 It is only useful as the argument of a
 &%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator,
 or a &%def%& condition.

+If certificate verification fails it may refer to a failing chain element
+which is not the leaf.

 
 .vitem &$tls_out_ourcert$&
 .vindex "&$tls_out_ourcert$&"
 
 .vitem &$tls_out_ourcert$&
 .vindex "&$tls_out_ourcert$&"


@@ -12428,13 +12636,15 @@ This variable refers to the certificate presented by the peer of an
 outbound connection.  It is only useful as the argument of a
 &%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator,
 or a &%def%& condition.
 outbound connection.  It is only useful as the argument of a
 &%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator,
 or a &%def%& condition.

+If certificate verification fails it may refer to a failing chain element
+which is not the leaf.

 
 .vitem &$tls_in_certificate_verified$&
 .vindex "&$tls_in_certificate_verified$&"
 This variable is set to &"1"& if a TLS certificate was verified when the
 message was received, and &"0"& otherwise.
 
 
 .vitem &$tls_in_certificate_verified$&
 .vindex "&$tls_in_certificate_verified$&"
 This variable is set to &"1"& if a TLS certificate was verified when the
 message was received, and &"0"& otherwise.
 

-The deprecated &$tls_certificate_verfied$& variable refers to the inbound side
+The deprecated &$tls_certificate_verified$& variable refers to the inbound side

 except when used in the context of an outbound SMTP delivery, when it refers to
 the outbound.
 
 except when used in the context of an outbound SMTP delivery, when it refers to
 the outbound.
 


@@ -12491,6 +12701,8 @@ When a message is received from a remote host over an encrypted SMTP
 connection, and Exim is configured to request a certificate from the client,
 the value of the Distinguished Name of the certificate is made available in the
 &$tls_in_peerdn$& during subsequent processing.
 connection, and Exim is configured to request a certificate from the client,
 the value of the Distinguished Name of the certificate is made available in the
 &$tls_in_peerdn$& during subsequent processing.

+If certificate verification fails it may refer to a failing chain element
+which is not the leaf.

 
 The deprecated &$tls_peerdn$& variable refers to the inbound side
 except when used in the context of an outbound SMTP delivery, when it refers to
 
 The deprecated &$tls_peerdn$& variable refers to the inbound side
 except when used in the context of an outbound SMTP delivery, when it refers to


@@ -12502,6 +12714,8 @@ When a message is being delivered to a remote host over an encrypted SMTP
 connection, and Exim is configured to request a certificate from the server,
 the value of the Distinguished Name of the certificate is made available in the
 &$tls_out_peerdn$& during subsequent processing.
 connection, and Exim is configured to request a certificate from the server,
 the value of the Distinguished Name of the certificate is made available in the
 &$tls_out_peerdn$& during subsequent processing.

+If certificate verification fails it may refer to a failing chain element
+which is not the leaf.

 
 .vitem &$tls_in_sni$&
 .vindex "&$tls_in_sni$&"
 
 .vitem &$tls_in_sni$&
 .vindex "&$tls_in_sni$&"


@@ -13132,6 +13346,7 @@ listed in more than one group.
 .row &%message_logs%&                "create per-message logs"
 .row &%preserve_message_logs%&       "after message completion"
 .row &%process_log_path%&            "for SIGUSR1 and &'exiwhat'&"
 .row &%message_logs%&                "create per-message logs"
 .row &%preserve_message_logs%&       "after message completion"
 .row &%process_log_path%&            "for SIGUSR1 and &'exiwhat'&"

+.row &%slow_lookup_log%&             "control logging of slow DNS lookups"

 .row &%syslog_duplication%&          "controls duplicate log lines on syslog"
 .row &%syslog_facility%&             "set syslog &""facility""& field"
 .row &%syslog_processname%&          "set syslog &""ident""& field"
 .row &%syslog_duplication%&          "controls duplicate log lines on syslog"
 .row &%syslog_facility%&             "set syslog &""facility""& field"
 .row &%syslog_processname%&          "set syslog &""ident""& field"


@@ -13245,6 +13460,7 @@ listed in more than one group.
 .row &%acl_smtp_mail%&               "ACL for MAIL"
 .row &%acl_smtp_mailauth%&           "ACL for AUTH on MAIL command"
 .row &%acl_smtp_mime%&               "ACL for MIME parts"
 .row &%acl_smtp_mail%&               "ACL for MAIL"
 .row &%acl_smtp_mailauth%&           "ACL for AUTH on MAIL command"
 .row &%acl_smtp_mime%&               "ACL for MIME parts"

+.row &%acl_smtp_notquit%&            "ACL for non-QUIT terminations"

 .row &%acl_smtp_predata%&            "ACL for start of data"
 .row &%acl_smtp_quit%&               "ACL for QUIT"
 .row &%acl_smtp_rcpt%&               "ACL for RCPT"
 .row &%acl_smtp_predata%&            "ACL for start of data"
 .row &%acl_smtp_quit%&               "ACL for QUIT"
 .row &%acl_smtp_rcpt%&               "ACL for RCPT"


@@ -13264,6 +13480,7 @@ listed in more than one group.
 .row &%helo_verify_hosts%&           "HELO hard-checked for these hosts"
 .row &%host_lookup%&                 "host name looked up for these hosts"
 .row &%host_lookup_order%&           "order of DNS and local name lookups"
 .row &%helo_verify_hosts%&           "HELO hard-checked for these hosts"
 .row &%host_lookup%&                 "host name looked up for these hosts"
 .row &%host_lookup_order%&           "order of DNS and local name lookups"

+.row &%hosts_proxy%&                 "use proxy protocol for these hosts"

 .row &%host_reject_connection%&      "reject connection from these hosts"
 .row &%hosts_treat_as_local%&        "useful in some cluster configurations"
 .row &%local_scan_timeout%&          "timeout for &[local_scan()]&"
 .row &%host_reject_connection%&      "reject connection from these hosts"
 .row &%hosts_treat_as_local%&        "useful in some cluster configurations"
 .row &%local_scan_timeout%&          "timeout for &[local_scan()]&"


@@ -13298,6 +13515,7 @@ listed in more than one group.
 .row &%tls_crl%&                     "certificate revocation list"
 .row &%tls_dh_max_bits%&             "clamp D-H bit count suggestion"
 .row &%tls_dhparam%&                 "DH parameters for server"
 .row &%tls_crl%&                     "certificate revocation list"
 .row &%tls_dh_max_bits%&             "clamp D-H bit count suggestion"
 .row &%tls_dhparam%&                 "DH parameters for server"

+.row &%tls_eccurve%&                 "EC curve selection for server"

 .row &%tls_ocsp_file%&               "location of server certificate status proof"
 .row &%tls_on_connect_ports%&        "specify SSMTP (SMTPS) ports"
 .row &%tls_privatekey%&              "location of server private key"
 .row &%tls_ocsp_file%&               "location of server certificate status proof"
 .row &%tls_on_connect_ports%&        "specify SSMTP (SMTPS) ports"
 .row &%tls_privatekey%&              "location of server private key"


@@ -13352,6 +13570,7 @@ listed in more than one group.
 See also the &'Policy controls'& section above.
 
 .table2
 See also the &'Policy controls'& section above.
 
 .table2

+.row &%dkim_verify_signers%&         "DKIM domain for which DKIM ACL is run"

 .row &%host_lookup%&                 "host name looked up for these hosts"
 .row &%host_lookup_order%&           "order of DNS and local name lookups"
 .row &%recipient_unqualified_hosts%& "may send unqualified recipients"
 .row &%host_lookup%&                 "host name looked up for these hosts"
 .row &%host_lookup_order%&           "order of DNS and local name lookups"
 .row &%recipient_unqualified_hosts%& "may send unqualified recipients"


@@ -13391,6 +13610,7 @@ See also the &'Policy controls'& section above.
 .table2
 .row &%accept_8bitmime%&             "advertise 8BITMIME"
 .row &%auth_advertise_hosts%&        "advertise AUTH to these hosts"
 .table2
 .row &%accept_8bitmime%&             "advertise 8BITMIME"
 .row &%auth_advertise_hosts%&        "advertise AUTH to these hosts"

+.row &%dsn_advertise_hosts%&         "advertise DSN extensions to these hosts"

 .row &%ignore_fromline_hosts%&       "allow &""From ""& from these hosts"
 .row &%ignore_fromline_local%&       "allow &""From ""& from local SMTP"
 .row &%pipelining_advertise_hosts%&  "advertise pipelining to these hosts"
 .row &%ignore_fromline_hosts%&       "allow &""From ""& from these hosts"
 .row &%ignore_fromline_local%&       "allow &""From ""& from local SMTP"
 .row &%pipelining_advertise_hosts%&  "advertise pipelining to these hosts"


@@ -13444,6 +13664,7 @@ See also the &'Policy controls'& section above.
 .row &%dns_ipv4_lookup%&             "only v4 lookup for these domains"
 .row &%dns_retrans%&                 "parameter for resolver"
 .row &%dns_retry%&                   "parameter for resolver"
 .row &%dns_ipv4_lookup%&             "only v4 lookup for these domains"
 .row &%dns_retrans%&                 "parameter for resolver"
 .row &%dns_retry%&                   "parameter for resolver"

+.row &%dns_trust_aa%&                "DNS zones trusted as authentic"

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


@@ -13546,8 +13767,9 @@ This option defines the ACL that is run after an SMTP DATA command has been
 processed and the message itself has been received, but before the final
 acknowledgment is sent. See chapter &<<CHAPACL>>& for further details.
 
 processed and the message itself has been received, but before the final
 acknowledgment is sent. See chapter &<<CHAPACL>>& for further details.
 

-.option acl_smtp_data_prdr main string&!! unset
-.cindex "DATA" "ACL for"
+.option acl_smtp_data_prdr main string&!! accept
+.cindex "PRDR" "ACL for"
+.cindex "DATA" "PRDR ACL for"

 .cindex "&ACL;" "PRDR-related"
 .cindex "&ACL;" "per-user data processing"
 This option defines the ACL that,
 .cindex "&ACL;" "PRDR-related"
 .cindex "&ACL;" "per-user data processing"
 This option defines the ACL that,


@@ -13556,6 +13778,12 @@ is run for each recipient after an SMTP DATA command has been
 processed and the message itself has been received, but before the
 acknowledgment is sent. See chapter &<<CHAPACL>>& for further details.
 
 processed and the message itself has been received, but before the
 acknowledgment is sent. See chapter &<<CHAPACL>>& for further details.
 

+.option acl_smtp_dkim main string&!! unset
+.cindex DKIM "ACL for"
+This option defines the ACL that is run for each DKIM signature
+of a received message.
+See chapter &<<CHAPdkim>>& for further details.
+

 .option acl_smtp_etrn main string&!! unset
 .cindex "ETRN" "ACL for"
 This option defines the ACL that is run when an SMTP ETRN command is
 .option acl_smtp_etrn main string&!! unset
 .cindex "ETRN" "ACL for"
 This option defines the ACL that is run when an SMTP ETRN command is


@@ -13590,6 +13818,12 @@ This option is available when Exim is built with the content-scanning
 extension. It defines the ACL that is run for each MIME part in a message. See
 section &<<SECTscanmimepart>>& for details.
 
 extension. It defines the ACL that is run for each MIME part in a message. See
 section &<<SECTscanmimepart>>& for details.
 

+.option acl_smtp_notquit main string&!! unset
+.cindex "not-QUIT, ACL for"
+This option defines the ACL that is run when an SMTP session
+ends without a QUIT command being received.
+See chapter &<<CHAPACL>>& for further details.
+

 .option acl_smtp_predata main string&!! unset
 This option defines the ACL that is run when an SMTP DATA command is
 received, before the message itself is received. See chapter &<<CHAPACL>>& for
 .option acl_smtp_predata main string&!! unset
 This option defines the ACL that is run when an SMTP DATA command is
 received, before the message itself is received. See chapter &<<CHAPACL>>& for


@@ -13646,7 +13880,7 @@ the local host's IP addresses.
 It appears that more and more DNS zone administrators are breaking the rules
 and putting domain names that look like IP addresses on the right hand side of
 MX records. Exim follows the rules and rejects this, giving an error message
 It appears that more and more DNS zone administrators are breaking the rules
 and putting domain names that look like IP addresses on the right hand side of
 MX records. Exim follows the rules and rejects this, giving an error message

-that explains the mis-configuration. However, some other MTAs support this
+that explains the misconfiguration. However, some other MTAs support this

 practice, so to avoid &"Why can't Exim do this?"& complaints,
 &%allow_mx_to_ip%& exists, in order to enable this heinous activity. It is not
 recommended, except when you have no other choice.
 practice, so to avoid &"Why can't Exim do this?"& complaints,
 &%allow_mx_to_ip%& exists, in order to enable this heinous activity. It is not
 recommended, except when you have no other choice.


@@ -14025,6 +14259,14 @@ etc. are ignored. If IP literals are enabled, the &(ipliteral)& router declines
 to handle IPv6 literal addresses.
 
 
 to handle IPv6 literal addresses.
 
 

+.option dkim_verify_signers main "domain list&!!" $dkim_signers
+.cindex DKIM "controlling calls to the ACL"
+This option gives a list of DKIM domains for which the DKIM ACL is run.
+It is expanded after the message is received; by default it runs
+the ACL once for each signature in the message.
+See chapter &<<CHAPdkim>>&.
+
+

 .option dns_again_means_nonexist main "domain list&!!" unset
 .cindex "DNS" "&""try again""& response; overriding"
 DNS lookups give a &"try again"& response for the DNS errors
 .option dns_again_means_nonexist main "domain list&!!" unset
 .cindex "DNS" "&""try again""& response; overriding"
 DNS lookups give a &"try again"& response for the DNS errors


@@ -14100,6 +14342,8 @@ servers have all been upgraded, there should be no need for this option.
 
 .option dns_retrans main time 0s
 .cindex "DNS" "resolver options"
 
 .option dns_retrans main time 0s
 .cindex "DNS" "resolver options"

+.cindex timeout "dns lookup"
+.cindex "DNS" timeout

 The options &%dns_retrans%& and &%dns_retry%& can be used to set the
 retransmission and retry parameters for DNS lookups. Values of zero (the
 defaults) leave the system default settings unchanged. The first value is the
 The options &%dns_retrans%& and &%dns_retry%& can be used to set the
 retransmission and retry parameters for DNS lookups. Values of zero (the
 defaults) leave the system default settings unchanged. The first value is the


@@ -14109,12 +14353,39 @@ take. I haven't found any documentation about timeouts on DNS lookups; these
 parameter values are available in the external resolver interface structure,
 but nowhere does it seem to describe how they are used or what you might want
 to set in them.
 parameter values are available in the external resolver interface structure,
 but nowhere does it seem to describe how they are used or what you might want
 to set in them.

+See also the &%slow_lookup_log%& option.

 
 
 .option dns_retry main integer 0
 See &%dns_retrans%& above.
 
 
 
 
 .option dns_retry main integer 0
 See &%dns_retrans%& above.
 
 

+.option dns_trust_aa main "domain list&!!" unset
+.cindex "DNS" "resolver options"
+.cindex "DNS" "DNSSEC"
+If this option is set then lookup results marked with the AA bit
+(Authoritative Answer) are trusted the same way as if they were
+DNSSEC-verified. The authority section's name of the answer must
+match with this expanded domain list.
+
+Use this option only if you talk directly to a resolver that is
+authoritative for some zones and does not set the AD (Authentic Data)
+bit in the answer. Some DNS servers may have an configuration option to
+mark the answers from their own zones as verified (they set the AD bit).
+Others do not have this option. It is considered as poor practice using
+a resolver that is an authoritative server for some zones.
+
+Use this option only if you really have to (e.g. if you want
+to use DANE for remote delivery to a server that is listed in the DNS
+zones that your resolver is authoritative for).
+
+If the DNS answer packet has the AA bit set and contains resource record
+in the answer section, the name of the first NS record appearing in the
+authority section is compared against the list. If the answer packet is
+authoritative but the answer section is empty, the name of the first SOA
+record in the authoritative section is used instead.
+
+.cindex "DNS" "resolver options"

 .option dns_use_edns0 main integer -1
 .cindex "DNS" "resolver options"
 .cindex "DNS" "EDNS0"
 .option dns_use_edns0 main integer -1
 .cindex "DNS" "resolver options"
 .cindex "DNS" "EDNS0"


@@ -14131,6 +14402,18 @@ This is an obsolete option that is now a no-op. It used to affect the way Exim
 handled CR and LF characters in incoming messages. What happens now is
 described in section &<<SECTlineendings>>&.
 
 handled CR and LF characters in incoming messages. What happens now is
 described in section &<<SECTlineendings>>&.
 

+.option dsn_advertise_hosts main "host list&!!" unset
+.cindex "bounce messages" "success"
+.cindex "DSN" "success"
+.cindex "Delivery Status Notification" "success"
+DSN extensions (RFC3461) will be advertised in the EHLO message to,
+and accepted from, these hosts.
+Hosts may use the NOTIFY and ENVID options on RCPT TO commands,
+and RET and ORCPT options on MAIL FROM commands.
+A NOTIFY=SUCCESS option requests success-DSN messages.
+A NOTIFY= option with no argument requests that no delay or failure DSNs
+are sent.
+

 .option dsn_from main "string&!!" "see below"
 .cindex "&'From:'& header line" "in bounces"
 .cindex "bounce messages" "&'From:'& line, specifying"
 .option dsn_from main "string&!!" "see below"
 .cindex "&'From:'& header line" "in bounces"
 .cindex "bounce messages" "&'From:'& line, specifying"


@@ -14148,7 +14431,7 @@ panic is logged, and the default value is used.
 Exim's transports have an option for adding an &'Envelope-to:'& header to a
 message when it is delivered, in exactly the same way as &'Return-path:'& is
 handled. &'Envelope-to:'& records the original recipient address from the
 Exim's transports have an option for adding an &'Envelope-to:'& header to a
 message when it is delivered, in exactly the same way as &'Return-path:'& is
 handled. &'Envelope-to:'& records the original recipient address from the

-messages's envelope that caused the delivery to happen. Such headers should not
+message's envelope that caused the delivery to happen. Such headers should not

 be present in incoming messages, and this option causes them to be removed at
 the time the message is received, to avoid any problems that might occur when a
 delivered message is subsequently sent on to some other recipient.
 be present in incoming messages, and this option causes them to be removed at
 the time the message is received, to avoid any problems that might occur when a
 delivered message is subsequently sent on to some other recipient.


@@ -14255,7 +14538,7 @@ routing, but which are not used for listening by the daemon. See section
 . Allow this long option name to split; give it unsplit as a fifth argument
 . for the automatic .oindex that is generated by .option.
 
 . Allow this long option name to split; give it unsplit as a fifth argument
 . for the automatic .oindex that is generated by .option.
 

-.option "extract_addresses_remove_ &~&~arguments" main boolean true &&&
+.option "extract_addresses_remove_arguments" main boolean true &&&

          extract_addresses_remove_arguments
 .oindex "&%-t%&"
 .cindex "command line" "addresses with &%-t%&"
          extract_addresses_remove_arguments
 .oindex "&%-t%&"
 .cindex "command line" "addresses with &%-t%&"


@@ -14439,14 +14722,17 @@ is an IP literal matching the calling address of the host, or
 matches the host name that Exim obtains by doing a reverse lookup of the
 calling host address, or
 .next
 matches the host name that Exim obtains by doing a reverse lookup of the
 calling host address, or
 .next

-when looked up using &[gethostbyname()]& (or &[getipnodebyname()]& when
-available) yields the calling host address.
+when looked up in DNS yields the calling host address.

 .endlist
 
 However, the EHLO or HELO command is not rejected if any of the checks
 fail. Processing continues, but the result of the check is remembered, and can
 be detected later in an ACL by the &`verify = helo`& condition.
 
 .endlist
 
 However, the EHLO or HELO command is not rejected if any of the checks
 fail. Processing continues, but the result of the check is remembered, and can
 be detected later in an ACL by the &`verify = helo`& condition.
 

+If DNS was used for successful verification, the variable
+.cindex "DNS" "DNSSEC"
+&$helo_verify_dnssec$& records the DNSSEC status of the lookups.
+

 .option helo_verify_hosts main "host list&!!" unset
 .cindex "HELO verifying" "mandatory"
 .cindex "EHLO" "verifying, mandatory"
 .option helo_verify_hosts main "host list&!!" unset
 .cindex "HELO verifying" "mandatory"
 .cindex "EHLO" "verifying, mandatory"


@@ -14550,6 +14836,14 @@ If the &%smtp_connection%& log selector is not set, this option has no effect.
 
 
 
 
 
 

+.new
+.option hosts_proxy main "host list&!!" unset
+.cindex proxy "proxy protocol"
+This option enables use of Proxy Protocol proxies for incoming
+connections.  For details see &<<SECTproxyInbound>>&.
+.wen
+
+

 .option hosts_treat_as_local main "domain list&!!" unset
 .cindex "local host" "domains treated as"
 .cindex "host" "treated as local"
 .option hosts_treat_as_local main "domain list&!!" unset
 .cindex "local host" "domains treated as"
 .cindex "host" "treated as local"


@@ -14820,8 +15114,9 @@ section &<<SECTmessiden>>&.
 This option sets the path which is used to determine the names of Exim's log
 files, or indicates that logging is to be to syslog, or both. It is expanded
 when Exim is entered, so it can, for example, contain a reference to the host
 This option sets the path which is used to determine the names of Exim's log
 files, or indicates that logging is to be to syslog, or both. It is expanded
 when Exim is entered, so it can, for example, contain a reference to the host

-name. If no specific path is set for the log files at compile or run time, they
-are written in a sub-directory called &_log_& in Exim's spool directory.
+name. If no specific path is set for the log files at compile or run time,
+or if the option is unset at run time (i.e.  &`log_file_path = `&)
+they are written in a sub-directory called &_log_& in Exim's spool directory.

 Chapter &<<CHAPlog>>& contains further details about Exim's logging, and
 section &<<SECTwhelogwri>>& describes how the contents of &%log_file_path%& are
 used. If this string is fixed at your installation (contains no expansion
 Chapter &<<CHAPlog>>& contains further details about Exim's logging, and
 section &<<SECTwhelogwri>>& describes how the contents of &%log_file_path%& are
 used. If this string is fixed at your installation (contains no expansion


@@ -14968,7 +15263,7 @@ If you use a virus-scanner and set this option to to a value larger than the
 maximum size that your virus-scanner is configured to support, you may get
 failures triggered by large mails.  The right size to configure for the
 virus-scanner depends upon what data is passed and the options in use but it's
 maximum size that your virus-scanner is configured to support, you may get
 failures triggered by large mails.  The right size to configure for the
 virus-scanner depends upon what data is passed and the options in use but it's

-probably safest to just set it to a little larger than this value.  Eg, with a
+probably safest to just set it to a little larger than this value.  E.g., with a

 default Exim message size of 50M and a default ClamAV StreamMaxLength of 10M,
 some problems may result.
 
 default Exim message size of 50M and a default ClamAV StreamMaxLength of 10M,
 some problems may result.
 


@@ -15208,9 +15503,9 @@ not count as protocol errors (see &%smtp_max_synprot_errors%&).
 This option can be used to enable the Per-Recipient Data Response extension
 to SMTP, defined by Eric Hall.
 If the option is set, PRDR is advertised by Exim when operating as a server.
 This option can be used to enable the Per-Recipient Data Response extension
 to SMTP, defined by Eric Hall.
 If the option is set, PRDR is advertised by Exim when operating as a server.

-If the client requests PRDR, and more than one recipient, for a message 
+If the client requests PRDR, and more than one recipient, for a message

 an additional ACL is called for each recipient after the message content
 an additional ACL is called for each recipient after the message content

-is recieved.  See section &<<SECTPRDRACL>>&.
+is received.  See section &<<SECTPRDRACL>>&.

 
 .option preserve_message_logs main boolean false
 .cindex "message logs" "preserving"
 
 .option preserve_message_logs main boolean false
 .cindex "message logs" "preserving"


@@ -15623,13 +15918,15 @@ the time of delivery. They are normally used only for final local deliveries.
 This option is an obsolete synonym for &%bounce_return_size_limit%&.
 
 
 This option is an obsolete synonym for &%bounce_return_size_limit%&.
 
 

-.option rfc1413_hosts main "host list&!!" *
+.option rfc1413_hosts main "host list&!!" @[]

 .cindex "RFC 1413"
 .cindex "host" "for RFC 1413 calls"
 .cindex "RFC 1413"
 .cindex "host" "for RFC 1413 calls"

-RFC 1413 identification calls are made to any client host which matches an item
-in the list.
+RFC 1413 identification calls are made to any client host which matches
+an item in the list.
+The default value specifies just this host, being any local interface
+for the system.

 
 

-.option rfc1413_query_timeout main time 5s
+.option rfc1413_query_timeout main time 0s

 .cindex "RFC 1413" "query timeout"
 .cindex "timeout" "for RFC 1413 call"
 This sets the timeout on RFC 1413 identification calls. If it is set to zero,
 .cindex "RFC 1413" "query timeout"
 .cindex "timeout" "for RFC 1413 call"
 This sets the timeout on RFC 1413 identification calls. If it is set to zero,


@@ -15648,6 +15945,16 @@ it qualifies them only if the message came from a host that matches
 using TCP/IP), and the &%-bnq%& option was not set.
 
 
 using TCP/IP), and the &%-bnq%& option was not set.
 
 

+.option slow_lookup_log main integer 0
+.cindex "logging" "slow lookups"
+.cindex "dns" "logging slow lookups"
+This option controls logging of slow lookups.
+If the value is nonzero it is taken as a number of milliseconds
+and lookups taking longer than this are logged.
+Currently this applies only to DNS lookups.
+
+
+

 .option smtp_accept_keepalive main boolean true
 .cindex "keepalive" "on incoming connection"
 This option controls the setting of the SO_KEEPALIVE option on incoming
 .option smtp_accept_keepalive main boolean true
 .cindex "keepalive" "on incoming connection"
 This option controls the setting of the SO_KEEPALIVE option on incoming


@@ -16023,7 +16330,7 @@ See &%smtp_ratelimit_hosts%& above.
 See &%smtp_ratelimit_hosts%& above.
 
 
 See &%smtp_ratelimit_hosts%& above.
 
 

-.option smtp_receive_timeout main time 5m
+.option smtp_receive_timeout main time&!! 5m

 .cindex "timeout" "for SMTP input"
 .cindex "SMTP" "input timeout"
 This sets a timeout value for SMTP reception. It applies to all forms of SMTP
 .cindex "timeout" "for SMTP input"
 .cindex "SMTP" "input timeout"
 This sets a timeout value for SMTP reception. It applies to all forms of SMTP


@@ -16038,6 +16345,10 @@ SMTP data timeout on connection from...
 The former means that Exim was expecting to read an SMTP command; the latter
 means that it was in the DATA phase, reading the contents of a message.
 
 The former means that Exim was expecting to read an SMTP command; the latter
 means that it was in the DATA phase, reading the contents of a message.
 

+If the first character of the option is a &"$"& the option is
+expanded before use and may depend on
+&$sender_host_name$&, &$sender_host_address$& and &$sender_host_port$&.
+

 
 .oindex "&%-os%&"
 The value set by this option can be overridden by the
 
 .oindex "&%-os%&"
 The value set by this option can be overridden by the


@@ -16310,7 +16621,9 @@ runs. This is appropriate behaviour for obtaining wall-clock time on some, but
 unfortunately not all, operating systems.
 
 
 unfortunately not all, operating systems.
 
 

-.option tls_advertise_hosts main "host list&!!" unset
+.new
+.option tls_advertise_hosts main "host list&!!" *
+.wen

 .cindex "TLS" "advertising"
 .cindex "encryption" "on SMTP connection"
 .cindex "SMTP" "encrypted connection"
 .cindex "TLS" "advertising"
 .cindex "encryption" "on SMTP connection"
 .cindex "SMTP" "encrypted connection"


@@ -16318,6 +16631,11 @@ When Exim is built with support for TLS encrypted connections, the availability
 of the STARTTLS command to set up an encrypted session is advertised in
 response to EHLO only to those client hosts that match this option. See
 chapter &<<CHAPTLS>>& for details of Exim's support for TLS.
 of the STARTTLS command to set up an encrypted session is advertised in
 response to EHLO only to those client hosts that match this option. See
 chapter &<<CHAPTLS>>& for details of Exim's support for TLS.

+.new
+Note that the default value requires that a certificate be supplied
+using the &%tls_certificate%& option.  If no certificate is available then
+the &%tls_advertise_hosts%& option should be set empty.
+.wen

 
 
 .option tls_certificate main string&!! unset
 
 
 .option tls_certificate main string&!! unset


@@ -16423,14 +16741,35 @@ prior to the 4.80 release, as Debian used to patch Exim to raise the minimum
 acceptable bound from 1024 to 2048.
 
 
 acceptable bound from 1024 to 2048.
 
 

+.option tls_eccurve main string&!! prime256v1
+.cindex TLS "EC cryptography"
+If built with a recent-enough version of OpenSSL,
+this option selects a EC curve for use by Exim.
+
+Curve names of the form &'prime256v1'& are accepted.
+For even more-recent library versions, names of the form &'P-512'&
+are also accepted, plus the special value &'auto'&
+which tell the library to choose.
+
+If the option is set to an empty string, no EC curves will be enabled.
+
+

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

+.cindex TLS "certificate status"
+.cindex TLS "OCSP proof file"

 This option
 must if set expand to the absolute path to a file which contains a current
 status proof for the server's certificate, as obtained from the
 Certificate Authority.
 
 This option
 must if set expand to the absolute path to a file which contains a current
 status proof for the server's certificate, as obtained from the
 Certificate Authority.
 

+.new
+Usable for GnuTLS 3.4.4 or 3.3.17 or OpenSSL 1.1.0 (or later).
+.wen
+

 
 .option tls_on_connect_ports main "string list" unset
 
 .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
 set up without waiting for the client to issue a STARTTLS command. For
 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
 set up without waiting for the client to issue a STARTTLS command. For


@@ -16477,17 +16816,23 @@ preference order of the available ciphers. Details are given in sections
 See &%tls_verify_hosts%& below.
 
 
 See &%tls_verify_hosts%& below.
 
 

-.option tls_verify_certificates main string&!! unset
+.option tls_verify_certificates main string&!! system

 .cindex "TLS" "client certificate verification"
 .cindex "certificate" "verification of client"
 .cindex "TLS" "client certificate verification"
 .cindex "certificate" "verification of client"

-The value of this option is expanded, and must then be the absolute path to
-a file containing permitted certificates for clients that
-match &%tls_verify_hosts%& or &%tls_try_verify_hosts%&. Alternatively, if you
-are using either GnuTLS version 3.3.6 (or later) or OpenSSL,
-you can set &%tls_verify_certificates%& to the name of a
-directory containing certificate files.
-For earlier versions of GnuTLS
-the option must be set to the name of a single file.
+The value of this option is expanded, and must then be either the
+word "system"
+or the absolute path to
+a file or directory containing permitted certificates for clients that
+match &%tls_verify_hosts%& or &%tls_try_verify_hosts%&.
+
+The "system" value for the option will use a
+system default location compiled into the SSL library.
+This is not available for GnuTLS versions preceding 3.0.20,
+and will be taken as empty; an explicit location
+must be specified.
+
+The use of a directory for the option value is not available for GnuTLS versions
+preceding 3.3.6 and a single file must be used.

 
 With OpenSSL the certificates specified
 explicitly
 
 With OpenSSL the certificates specified
 explicitly


@@ -16932,6 +17277,25 @@ or for any deliveries caused by this router. You should not set this option
 unless you really, really know what you are doing. See also the generic
 transport option of the same name.
 
 unless you really, really know what you are doing. See also the generic
 transport option of the same name.
 

+.option dnssec_request_domains routers "domain list&!!" unset
+.cindex "MX record" "security"
+.cindex "DNSSEC" "MX lookup"
+.cindex "security" "MX lookup"
+.cindex "DNS" "DNSSEC"
+DNS lookups for domains matching &%dnssec_request_domains%& will be done with
+the dnssec request bit set.
+This applies to all of the SRV, MX, AAAA, A lookup sequence.
+
+.option dnssec_require_domains routers "domain list&!!" unset
+.cindex "MX record" "security"
+.cindex "DNSSEC" "MX lookup"
+.cindex "security" "MX lookup"
+.cindex "DNS" "DNSSEC"
+DNS lookups for domains matching &%dnssec_request_domains%& will be done with
+the dnssec request bit set.  Any returns not having the Authenticated Data bit
+(AD bit) set will be ignored and logged as a host-lookup failure.
+This applies to all of the SRV, MX, AAAA, A lookup sequence.
+

 
 .option domains routers&!? "domain list&!!" unset
 .cindex "router" "restricting to specific domains"
 
 .option domains routers&!? "domain list&!!" unset
 .cindex "router" "restricting to specific domains"


@@ -16949,6 +17313,15 @@ This option must always be set. It specifies which of the available routers is
 to be used.
 
 
 to be used.
 
 

+.option dsn_lasthop routers boolean false
+.cindex "DSN" "success"
+.cindex "Delivery Status Notification" "success"
+If this option is set true, and extended DSN (RFC3461) processing is in effect,
+Exim will not pass on DSN requests to downstream DSN-aware hosts but will
+instead send a success DSN as if the next hop does not support DSN.
+Not effective on redirect routers.
+
+

 
 .option errors_to routers string&!! unset
 .cindex "envelope sender"
 
 .option errors_to routers string&!! unset
 .cindex "envelope sender"


@@ -17070,7 +17443,8 @@ and the discussion in chapter &<<CHAPenvironment>>&.
 .option headers_add routers list&!! unset
 .cindex "header lines" "adding"
 .cindex "router" "adding header lines"
 .option headers_add routers list&!! unset
 .cindex "header lines" "adding"
 .cindex "router" "adding header lines"

-This option specifies a list of text headers, newline-separated,
+This option specifies a list of text headers,
+newline-separated (by default, changeable in the usual way),

 that is associated with any addresses that are accepted by the router.
 Each item is separately expanded, at routing time.  However, this
 option has no effect when an address is just being verified. The way in which
 that is associated with any addresses that are accepted by the router.
 Each item is separately expanded, at routing time.  However, this
 option has no effect when an address is just being verified. The way in which


@@ -17107,7 +17481,8 @@ avoided. The &%repeat_use%& option of the &%redirect%& router may be of help.
 .option headers_remove routers list&!! unset
 .cindex "header lines" "removing"
 .cindex "router" "removing header lines"
 .option headers_remove routers list&!! unset
 .cindex "header lines" "removing"
 .cindex "router" "removing header lines"

-This option specifies a list of text headers, colon-separated,
+This option specifies a list of text headers,
+colon-separated (by default, changeable in the usual way),

 that is associated with any addresses that are accepted by the router.
 Each item is separately expanded, at routing time.  However, this
 option has no effect when an address is just being verified. The way in which
 that is associated with any addresses that are accepted by the router.
 Each item is separately expanded, at routing time.  However, this
 option has no effect when an address is just being verified. The way in which


@@ -17133,6 +17508,11 @@ removal requests are deleted when the address is passed on to subsequent
 routers, and this can lead to problems with duplicates -- see the similar
 warning for &%headers_add%& above.
 
 routers, and this can lead to problems with duplicates -- see the similar
 warning for &%headers_add%& above.
 

+&*Warning 3*&: Because of the separate expansion of the list items,
+items that contain a list separator must have it doubled.
+To avoid this, change the list separator (&<<SECTlistsepchange>>&).
+
+

 
 .option ignore_target_hosts routers "host list&!!" unset
 .cindex "IP address" "discarding"
 
 .option ignore_target_hosts routers "host list&!!" unset
 .cindex "IP address" "discarding"


@@ -17864,7 +18244,7 @@ happens is controlled by the generic &%self%& option.
 
 .section "Problems with DNS lookups" "SECTprowitdnsloo"
 There have been problems with DNS servers when SRV records are looked up.
 
 .section "Problems with DNS lookups" "SECTprowitdnsloo"
 There have been problems with DNS servers when SRV records are looked up.

-Some mis-behaving servers return a DNS error or timeout when a non-existent
+Some misbehaving servers return a DNS error or timeout when a non-existent

 SRV record is sought. Similar problems have in the past been reported for
 MX records. The global &%dns_again_means_nonexist%& option can help with this
 problem, but it is heavy-handed because it is a global option.
 SRV record is sought. Similar problems have in the past been reported for
 MX records. The global &%dns_again_means_nonexist%& option can help with this
 problem, but it is heavy-handed because it is a global option.


@@ -17886,6 +18266,9 @@ There are a few cases where a &(dnslookup)& router will decline to accept
 an address; if such a router is expected to handle "all remaining non-local
 domains", then it is important to set &%no_more%&.
 
 an address; if such a router is expected to handle "all remaining non-local
 domains", then it is important to set &%no_more%&.
 

+The router will defer rather than decline if the domain
+is found in the &%fail_defer_domains%& router option.
+

 Reasons for a &(dnslookup)& router to decline currently include:
 .ilist
 The domain does not exist in DNS
 Reasons for a &(dnslookup)& router to decline currently include:
 .ilist
 The domain does not exist in DNS


@@ -17964,27 +18347,16 @@ when there is a DNS lookup error.
 
 
 
 
 
 

-.option dnssec_request_domains dnslookup "domain list&!!" unset
-.cindex "MX record" "security"
-.cindex "DNSSEC" "MX lookup"
-.cindex "security" "MX lookup"
-.cindex "DNS" "DNSSEC"
-DNS lookups for domains matching &%dnssec_request_domains%& will be done with
-the dnssec request bit set.
-This applies to all of the SRV, MX A6, AAAA, A lookup sequence.
-
-
-
-.option dnssec_require_domains dnslookup "domain list&!!" unset
-.cindex "MX record" "security"
-.cindex "DNSSEC" "MX lookup"
-.cindex "security" "MX lookup"
-.cindex "DNS" "DNSSEC"
-DNS lookups for domains matching &%dnssec_request_domains%& will be done with
-the dnssec request bit set.  Any returns not having the Authenticated Data bit
-(AD bit) set wil be ignored and logged as a host-lookup failure.
-This applies to all of the SRV, MX A6, AAAA, A lookup sequence.

 
 

+.option fail_defer_domains dnslookup "domain list&!!" unset
+.cindex "MX record" "not found"
+DNS lookups for domains matching &%fail_defer_domains%&
+which find no matching record will cause the router to defer
+rather than the default behaviour of decline.
+This maybe be useful for queueing messages for a newly created
+domain while the DNS configuration is not ready.
+However, it will result in any message with mistyped domains
+also being queued.

 
 
 .option mx_domains dnslookup "domain list&!!" unset
 
 
 .option mx_domains dnslookup "domain list&!!" unset


@@ -18955,6 +19327,11 @@ However, there are some private options which define transports for delivery to
 files and pipes, and for generating autoreplies. See the &%file_transport%&,
 &%pipe_transport%& and &%reply_transport%& descriptions below.
 
 files and pipes, and for generating autoreplies. See the &%file_transport%&,
 &%pipe_transport%& and &%reply_transport%& descriptions below.
 

+If success DSNs have been requested
+.cindex "DSN" "success"
+.cindex "Delivery Status Notification" "success"
+redirection triggers one and the DSN options are not passed any further.
+

 
 
 .section "Redirection data" "SECID124"
 
 
 .section "Redirection data" "SECID124"


@@ -19221,7 +19598,7 @@ the router to decline. Instead, the alias item
 .cindex "black hole"
 .cindex "abandoning mail"
 &':blackhole:'& can be used. It does what its name implies. No delivery is
 .cindex "black hole"
 .cindex "abandoning mail"
 &':blackhole:'& can be used. It does what its name implies. No delivery is

-done, and no error message is generated. This has the same effect as specifing
+done, and no error message is generated. This has the same effect as specifying

 &_/dev/null_& as a destination, but it can be independently disabled.
 
 &*Warning*&: If &':blackhole:'& appears anywhere in a redirection list, no
 &_/dev/null_& as a destination, but it can be independently disabled.
 
 &*Warning*&: If &':blackhole:'& appears anywhere in a redirection list, no


@@ -20147,7 +20524,8 @@ value that the router supplies, and also overriding any value associated with
 .option headers_add transports list&!! unset
 .cindex "header lines" "adding in transport"
 .cindex "transport" "header lines; adding"
 .option headers_add transports list&!! unset
 .cindex "header lines" "adding in transport"
 .cindex "transport" "header lines; adding"

-This option specifies a list of text headers, newline-separated,
+This option specifies a list of text headers,
+newline-separated (by default, changeable in the usual way),

 which are (separately) expanded and added to the header
 portion of a message as it is transported, as described in section
 &<<SECTheadersaddrem>>&. Additional header lines can also be specified by
 which are (separately) expanded and added to the header
 portion of a message as it is transported, as described in section
 &<<SECTheadersaddrem>>&. Additional header lines can also be specified by


@@ -20172,7 +20550,8 @@ checked, since this option does not automatically suppress them.
 .option headers_remove transports list&!! unset
 .cindex "header lines" "removing"
 .cindex "transport" "header lines; removing"
 .option headers_remove transports list&!! unset
 .cindex "header lines" "removing"
 .cindex "transport" "header lines; removing"

-This option specifies a list of header names, colon-separated;
+This option specifies a list of header names,
+colon-separated (by default, changeable in the usual way);

 these headers are omitted from the message as it is transported, as described
 in section &<<SECTheadersaddrem>>&. Header removal can also be specified by
 routers.
 these headers are omitted from the message as it is transported, as described
 in section &<<SECTheadersaddrem>>&. Header removal can also be specified by
 routers.


@@ -20184,6 +20563,10 @@ errors and cause the delivery to be deferred.
 Unlike most options, &%headers_remove%& can be specified multiple times
 for a router; all listed headers are removed.
 
 Unlike most options, &%headers_remove%& can be specified multiple times
 for a router; all listed headers are removed.
 

+&*Warning*&: Because of the separate expansion of the list items,
+items that contain a list separator must have it doubled.
+To avoid this, change the list separator (&<<SECTlistsepchange>>&).
+

 
 
 .option headers_rewrite transports string unset
 
 
 .option headers_rewrite transports string unset


@@ -20232,6 +20615,32 @@ transport, the &[initgroups()]& function is called when running the transport
 to ensure that any additional groups associated with the uid are set up.
 
 
 to ensure that any additional groups associated with the uid are set up.
 
 

+.new
+.option max_parallel transports integer&!! unset
+.cindex limit "transport parallelism"
+.cindex transport "parallel processes"
+.cindex transport "concurrency limit"
+.cindex "delivery" "parallelism for transport"
+If this option is set and expands to an integer greater than zero
+it limits the number of concurrent runs of the transport.
+The control does not apply to shadow transports.
+
+.cindex "hints database" "transport concurrency control"
+Exim implements this control by means of a hints database in which a record is
+incremented whenever a transport process is beaing created. The record
+is decremented and possibly removed when the process terminates.
+Obviously there is scope for
+records to get left lying around if there is a system or program crash. To
+guard against this, Exim ignores any records that are more than six hours old.
+
+If you use this option, you should also arrange to delete the
+relevant hints database whenever your system reboots. The names of the files
+start with &_misc_& and they are kept in the &_spool/db_& directory. There
+may be one or two files, depending on the type of DBM in use. The same files
+are used for ETRN and smtp transport serialization.
+.wen
+
+

 .option message_size_limit transports string&!! 0
 .cindex "limit" "message size per transport"
 .cindex "size" "of message, limit"
 .option message_size_limit transports string&!! 0
 .cindex "limit" "message size per transport"
 .cindex "size" "of message, limit"


@@ -20378,6 +20787,9 @@ headers that some sites insist on.
 This option sets up a filtering (in the Unix shell sense) process for messages
 at transport time. It should not be confused with mail filtering as set up by
 individual users or via a system filter.
 This option sets up a filtering (in the Unix shell sense) process for messages
 at transport time. It should not be confused with mail filtering as set up by
 individual users or via a system filter.

+.new
+If unset, or expanding to an empty string, no filtering is done.
+.wen

 
 When the message is about to be written out, the command specified by
 &%transport_filter%& is started up in a separate, parallel process, and
 
 When the message is about to be written out, the command specified by
 &%transport_filter%& is started up in a separate, parallel process, and


@@ -22129,6 +22541,10 @@ If two messages arrive at almost the same time, and both are routed to a pipe
 delivery, the two pipe transports may be run concurrently. You must ensure that
 any pipe commands you set up are robust against this happening. If the commands
 write to a file, the &%exim_lock%& utility might be of use.
 delivery, the two pipe transports may be run concurrently. You must ensure that
 any pipe commands you set up are robust against this happening. If the commands
 write to a file, the &%exim_lock%& utility might be of use.

+.new
+Alternatively the &%max_parallel%& option could be used with a value
+of "1" to enforce serialization.
+.wen

 
 
 
 
 
 


@@ -22393,6 +22809,7 @@ Note that &$address_pipe$& is handled specially in &%command%& when
 &%force_command%& is set, expanding out to the original argument vector as
 separate items, similarly to a Unix shell &`"$@"`& construct.
 
 &%force_command%& is set, expanding out to the original argument vector as
 separate items, similarly to a Unix shell &`"$@"`& construct.
 

+

 .option ignore_status pipe boolean false
 If this option is true, the status returned by the subprocess that is set up to
 run the command is ignored, and Exim behaves as if zero had been returned.
 .option ignore_status pipe boolean false
 If this option is true, the status returned by the subprocess that is set up to
 run the command is ignored, and Exim behaves as if zero had been returned.


@@ -22403,27 +22820,29 @@ from the transport unless the status value is one of those listed in
 &*Note*&: This option does not apply to timeouts, which do not return a status.
 See the &%timeout_defer%& option for how timeouts are handled.
 
 &*Note*&: This option does not apply to timeouts, which do not return a status.
 See the &%timeout_defer%& option for how timeouts are handled.
 

+

 .option log_defer_output pipe boolean false
 .cindex "&(pipe)& transport" "logging output"
 If this option is set, and the status returned by the command is
 one of the codes listed in &%temp_errors%& (that is, delivery was deferred),
 .option log_defer_output pipe boolean false
 .cindex "&(pipe)& transport" "logging output"
 If this option is set, and the status returned by the command is
 one of the codes listed in &%temp_errors%& (that is, delivery was deferred),

-and any output was produced, the first line of it is written to the main log.
+and any output was produced on stdout or stderr, the first line of it is
+written to the main log.

 
 
 .option log_fail_output pipe boolean false
 
 
 .option log_fail_output pipe boolean false

-If this option is set, and the command returns any output, and also ends with a
-return code that is neither zero nor one of the return codes listed in
-&%temp_errors%& (that is, the delivery failed), the first line of output is
-written to the main log. This option and &%log_output%& are mutually exclusive.
-Only one of them may be set.
-
+If this option is set, and the command returns any output on stdout or
+stderr, and also ends with a return code that is neither zero nor one of
+the return codes listed in &%temp_errors%& (that is, the delivery
+failed), the first line of output is written to the main log. This
+option and &%log_output%& are mutually exclusive.  Only one of them may
+be set.

 
 
 .option log_output pipe boolean false
 
 
 .option log_output pipe boolean false

-If this option is set and the command returns any output, the first line of
-output is written to the main log, whatever the return code. This option and
-&%log_fail_output%& are mutually exclusive. Only one of them may be set.
-
+If this option is set and the command returns any output on stdout or
+stderr, the first line of output is written to the main log, whatever
+the return code. This option and &%log_fail_output%& are mutually
+exclusive. Only one of them may be set.

 
 
 .option max_output pipe integer 20K
 
 
 .option max_output pipe integer 20K


@@ -22897,7 +23316,7 @@ details.
 .cindex "DNS" "DNSSEC"
 DNS lookups for domains matching &%dnssec_request_domains%& will be done with
 the dnssec request bit set.
 .cindex "DNS" "DNSSEC"
 DNS lookups for domains matching &%dnssec_request_domains%& will be done with
 the dnssec request bit set.

-This applies to all of the SRV, MX A6, AAAA, A lookup sequence.
+This applies to all of the SRV, MX, AAAA, A lookup sequence.

 
 
 
 
 
 


@@ -22908,8 +23327,8 @@ This applies to all of the SRV, MX A6, AAAA, A lookup sequence.
 .cindex "DNS" "DNSSEC"
 DNS lookups for domains matching &%dnssec_request_domains%& will be done with
 the dnssec request bit set.  Any returns not having the Authenticated Data bit
 .cindex "DNS" "DNSSEC"
 DNS lookups for domains matching &%dnssec_request_domains%& will be done with
 the dnssec request bit set.  Any returns not having the Authenticated Data bit

-(AD bit) set wil be ignored and logged as a host-lookup failure.
-This applies to all of the SRV, MX A6, AAAA, A lookup sequence.
+(AD bit) set will be ignored and logged as a host-lookup failure.
+This applies to all of the SRV, MX, AAAA, A lookup sequence.

 
 
 
 
 
 


@@ -23060,12 +23479,11 @@ that matches this list, even if the server host advertises PIPELINING support.
 Exim will not try to start a TLS session when delivering to any host that
 matches this list. See chapter &<<CHAPTLS>>& for details of TLS.
 
 Exim will not try to start a TLS session when delivering to any host that
 matches this list. See chapter &<<CHAPTLS>>& for details of TLS.
 

-.option hosts_verify_avoid_tls smtp "host list&!!" *
+.option hosts_verify_avoid_tls smtp "host list&!!" unset

 .cindex "TLS" "avoiding for certain hosts"
 Exim will not try to start a TLS session for a verify callout,
 or when delivering in cutthrough mode,
 to any host that matches this list.
 .cindex "TLS" "avoiding for certain hosts"
 Exim will not try to start a TLS session for a verify callout,
 or when delivering in cutthrough mode,
 to any host that matches this list.

-Note that the default is to not use TLS.

 
 
 .option hosts_max_try smtp integer 5
 
 
 .option hosts_max_try smtp integer 5


@@ -23162,11 +23580,12 @@ connects. If authentication fails, Exim will try to transfer the message
 unauthenticated. See also &%hosts_require_auth%&, and chapter
 &<<CHAPSMTPAUTH>>& for details of authentication.
 
 unauthenticated. See also &%hosts_require_auth%&, and chapter
 &<<CHAPSMTPAUTH>>& for details of authentication.
 

-.option hosts_try_prdr smtp "host list&!!" unset
+.option hosts_try_prdr smtp "host list&!!" *

 .cindex "PRDR" "enabling, optional in client"
 This option provides a list of servers to which, provided they announce
 PRDR support, Exim will attempt to negotiate PRDR
 for multi-recipient messages.
 .cindex "PRDR" "enabling, optional in client"
 This option provides a list of servers to which, provided they announce
 PRDR support, Exim will attempt to negotiate PRDR
 for multi-recipient messages.

+The option can usually be left as default.

 
 .option interface smtp "string list&!!" unset
 .cindex "bind IP address"
 
 .option interface smtp "string list&!!" unset
 .cindex "bind IP address"


@@ -23224,7 +23643,7 @@ so can cause parallel connections to the same host if &%remote_max_parallel%&
 permits this.
 
 
 permits this.
 
 

-.option multi_domain smtp boolean true
+.option multi_domain smtp boolean&!! true

 .vindex "&$domain$&"
 When this option is set, the &(smtp)& transport can handle a number of
 addresses containing a mixture of different domains provided they all resolve
 .vindex "&$domain$&"
 When this option is set, the &(smtp)& transport can handle a number of
 addresses containing a mixture of different domains provided they all resolve


@@ -23233,6 +23652,9 @@ handling only one domain at a time. This is useful if you want to use
 &$domain$& in an expansion for the transport, because it is set only when there
 is a single domain involved in a remote delivery.
 
 &$domain$& in an expansion for the transport, because it is set only when there
 is a single domain involved in a remote delivery.
 

+It is expanded per-address and can depend on any of
+&$address_data$&, &$domain_data$&, &$local_part_data$&,
+&$host$&, &$host_address$& and &$host_port$&.

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


@@ -23262,7 +23684,7 @@ protocol (RFC 2033) instead of SMTP. This protocol is sometimes used for local
 deliveries into closed message stores. Exim also has support for running LMTP
 over a pipe to a local process &-- see chapter &<<CHAPLMTP>>&.
 
 deliveries into closed message stores. Exim also has support for running LMTP
 over a pipe to a local process &-- see chapter &<<CHAPLMTP>>&.
 

-If this option is set to &"smtps"&, the default vaule for the &%port%& option
+If this option is set to &"smtps"&, the default value for the &%port%& option

 changes to &"smtps"&, and the transport initiates TLS immediately after
 connecting, as an outbound SSL-on-connect, instead of using STARTTLS to upgrade.
 The Internet standards bodies strongly discourage use of this mode.
 changes to &"smtps"&, and the transport initiates TLS immediately after
 connecting, as an outbound SSL-on-connect, instead of using STARTTLS to upgrade.
 The Internet standards bodies strongly discourage use of this mode.


@@ -23305,6 +23727,10 @@ start with &_misc_& and they are kept in the &_spool/db_& directory. There
 may be one or two files, depending on the type of DBM in use. The same files
 are used for ETRN serialization.
 
 may be one or two files, depending on the type of DBM in use. The same files
 are used for ETRN serialization.
 

+.new
+See also the &%max_parallel%& generic transport option.
+.wen
+

 
 .option size_addition smtp integer 1024
 .cindex "SMTP" "SIZE"
 
 .option size_addition smtp integer 1024
 .cindex "SMTP" "SIZE"


@@ -23323,6 +23749,14 @@ Alternatively, if the value of &%size_addition%& is set negative, it disables
 the use of the SIZE option altogether.
 
 
 the use of the SIZE option altogether.
 
 

+.new
+.option socks_proxy smtp string&!! unset
+.cindex proxy SOCKS
+This option enables use of SOCKS proxies for connections made by the
+transport.  For details see &<<SECTproxySOCKS>>&.
+.wen
+
+

 .option tls_certificate smtp string&!! unset
 .cindex "TLS" "client certificate, location of"
 .cindex "certificate" "client, location of"
 .option tls_certificate smtp string&!! unset
 .cindex "TLS" "client certificate, location of"
 .cindex "certificate" "client, location of"


@@ -23417,7 +23851,7 @@ unknown state), opens a new one to the same host, and then tries the delivery
 in clear.
 
 
 in clear.
 
 

-.option tls_try_verify_hosts smtp "host list&!!" unset
+.option tls_try_verify_hosts smtp "host list&!!" *

 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 This option gives a list of hosts for which, on encrypted connections,
 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 This option gives a list of hosts for which, on encrypted connections,


@@ -23430,20 +23864,37 @@ The &$tls_out_certificate_verified$& variable is set when
 certificate verification succeeds.
 
 
 certificate verification succeeds.
 
 

-.option tls_verify_certificates smtp string&!! unset
+.option tls_verify_cert_hostnames smtp "host list&!!" *
+.cindex "TLS" "server certificate hostname verification"
+.cindex "certificate" "verification of server"
+This option give a list of hosts for which,
+while verifying the server certificate,
+checks will be included on the host name
+(note that this will generally be the result of a DNS MX lookup)
+versus Subject and Subject-Alternate-Name fields.  Wildcard names are permitted
+limited to being the initial component of a 3-or-more component FQDN.
+
+There is no equivalent checking on client certificates.
+
+
+.option tls_verify_certificates smtp string&!! system

 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 .vindex "&$host$&"
 .vindex "&$host_address$&"
 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 .vindex "&$host$&"
 .vindex "&$host_address$&"

-The value of this option must be the absolute path to a file containing
-permitted server certificates, for use when setting up an encrypted connection.
-Alternatively,
-if you are using either GnuTLS version 3.3.6 (or later) or OpenSSL,
-you can set
-&%tls_verify_certificates%& to the name of a directory containing certificate
-files.
-For earlier versions of GnuTLS the option must be set to the name of a
-single file.
+The value of this option must be either the
+word "system"
+or the absolute path to
+a file or directory containing permitted certificates for servers,
+for use when setting up an encrypted connection.
+
+The "system" value for the option will use a location compiled into the SSL library.
+This is not available for GnuTLS versions preceding 3.0.20; a value of "system"
+is taken as empty and an explicit location
+must be specified.
+
+The use of a directory for the option value is not available for GnuTLS versions
+preceding 3.3.6 and a single file must be used.

 
 With OpenSSL the certificates specified
 explicitly
 
 With OpenSSL the certificates specified
 explicitly


@@ -23454,8 +23905,9 @@ The values of &$host$& and
 &$host_address$& are set to the name and address of the server during the
 expansion of this option. See chapter &<<CHAPTLS>>& for details of TLS.
 
 &$host_address$& are set to the name and address of the server during the
 expansion of this option. See chapter &<<CHAPTLS>>& for details of TLS.
 

-For back-compatability,
+For back-compatibility,

 if neither tls_verify_hosts nor tls_try_verify_hosts are set
 if neither tls_verify_hosts nor tls_try_verify_hosts are set

+(a single-colon empty list counts as being set)

 and certificate verification fails the TLS connection is closed.
 
 
 and certificate verification fails the TLS connection is closed.
 
 


@@ -23938,7 +24390,7 @@ replaced, not just the working part. The replacement must be a complete RFC
 2822 address, including the angle brackets if necessary. If text outside angle
 brackets contains a character whose value is greater than 126 or less than 32
 (except for tab), the text is encoded according to RFC 2047. The character set
 2822 address, including the angle brackets if necessary. If text outside angle
 brackets contains a character whose value is greater than 126 or less than 32
 (except for tab), the text is encoded according to RFC 2047. The character set

-is taken from &%headers_charset%&, which defaults to ISO-8859-1.
+is taken from &%headers_charset%&, which gets its default at build time.

 
 When the &"w"& flag is set on a rule that causes an envelope address to be
 rewritten, all but the working part of the replacement address is discarded.
 
 When the &"w"& flag is set on a rule that causes an envelope address to be
 rewritten, all but the working part of the replacement address is discarded.


@@ -24210,6 +24662,13 @@ A server unexpectedly closed the SMTP connection. There may, of course,
 legitimate reasons for this (host died, network died), but if it repeats a lot
 for the same host, it indicates something odd.
 
 legitimate reasons for this (host died, network died), but if it repeats a lot
 for the same host, it indicates something odd.
 

+.vitem &%lookup%&
+A DNS lookup for a host failed.
+Note that a &%dnslookup%& router will need to have matched
+its &%fail_defer_domains%& option for this retry type to be usable.
+Also note that a &%manualroute%& router will probably need
+its &%host_find_failed%& option set to &%defer%&.
+

 .vitem &%refused_MX%&
 A connection to a host obtained from an MX record was refused.
 
 .vitem &%refused_MX%&
 A connection to a host obtained from an MX record was refused.
 


@@ -24621,6 +25080,7 @@ AUTH_GSASL=yes
 AUTH_HEIMDAL_GSSAPI=yes
 AUTH_PLAINTEXT=yes
 AUTH_SPA=yes
 AUTH_HEIMDAL_GSSAPI=yes
 AUTH_PLAINTEXT=yes
 AUTH_SPA=yes

+AUTH_TLS=yes

 .endd
 in &_Local/Makefile_&, respectively. The first of these supports the CRAM-MD5
 authentication mechanism (RFC 2195), and the second provides an interface to
 .endd
 in &_Local/Makefile_&, respectively. The first of these supports the CRAM-MD5
 authentication mechanism (RFC 2195), and the second provides an interface to


@@ -24635,6 +25095,8 @@ The sixth can be configured to support
 the PLAIN authentication mechanism (RFC 2595) or the LOGIN mechanism, which is
 not formally documented, but used by several MUAs. The seventh authenticator
 supports Microsoft's &'Secure Password Authentication'& mechanism.
 the PLAIN authentication mechanism (RFC 2595) or the LOGIN mechanism, which is
 not formally documented, but used by several MUAs. The seventh authenticator
 supports Microsoft's &'Secure Password Authentication'& mechanism.

+The eighth is an Exim authenticator but not an SMTP one;
+instead it can use information from a TLS negotiation.

 
 The authenticators are configured using the same syntax as other drivers (see
 section &<<SECTfordricon>>&). If no authenticators are required, no
 
 The authenticators are configured using the same syntax as other drivers (see
 section &<<SECTfordricon>>&). If no authenticators are required, no


@@ -24706,7 +25168,7 @@ client_condition = ${if !eq{$tls_out_cipher}{}}
 
 .option client_set_id authenticators string&!! unset
 When client authentication succeeds, this condition is expanded; the
 
 .option client_set_id authenticators string&!! unset
 When client authentication succeeds, this condition is expanded; the

-result is used in the log lines for outbound messasges.
+result is used in the log lines for outbound messages.

 Typically it will be the user name used for authentication.
 
 
 Typically it will be the user name used for authentication.
 
 


@@ -25354,7 +25816,7 @@ cyrusless_crammd5:
   driver = cram_md5
   public_name = CRAM-MD5
   server_secret = ${lookup{$auth1:mail.example.org:userPassword}\
   driver = cram_md5
   public_name = CRAM-MD5
   server_secret = ${lookup{$auth1:mail.example.org:userPassword}\

-                  dbmjz{/etc/sasldb2}}
+                  dbmjz{/etc/sasldb2}{$value}fail}

   server_set_id = $auth1
 .endd
 
   server_set_id = $auth1
 .endd
 


@@ -25724,7 +26186,7 @@ The value should be a pathname, with no &"file:"& prefix.
 
 .option server_service heimdal_gssapi string&!! "smtp"
 This option specifies the service identifier used, in conjunction with
 
 .option server_service heimdal_gssapi string&!! "smtp"
 This option specifies the service identifier used, in conjunction with

-&%server_hostname%&, for building the identifer for finding credentials
+&%server_hostname%&, for building the identifier for finding credentials

 from the keytab.
 
 
 from the keytab.
 
 


@@ -25841,6 +26303,79 @@ msn:
 
 
 
 
 
 

+. ////////////////////////////////////////////////////////////////////////////
+. ////////////////////////////////////////////////////////////////////////////
+
+.chapter "The tls authenticator" "CHAPtlsauth"
+.scindex IIDtlsauth1 "&(tls)& authenticator"
+.scindex IIDtlsauth2 "authenticators" "&(tls)&"
+.cindex "authentication" "Client Certificate"
+.cindex "authentication" "X509"
+.cindex "Certificate-based authentication"
+The &(tls)& authenticator provides server support for
+authentication based on client certificates.
+
+It is not an SMTP authentication mechanism and is not
+advertised by the server as part of the SMTP EHLO response.
+It is an Exim authenticator in the sense that it affects
+the protocol element of the log line, can be tested for
+by the &%authenticated%& ACL condition, and can set
+the &$authenticated_id$& variable.
+
+The client must present a verifiable certificate,
+for which it must have been requested via the
+&%tls_verify_hosts%& or &%tls_try_verify_hosts%& main options
+(see &<<CHAPTLS>>&).
+
+If an authenticator of this type is configured it is
+run before any SMTP-level communication is done,
+and can authenticate the connection.
+If it does, SMTP authentication is not offered.
+
+A maximum of one authenticator of this type may be present.
+
+
+.cindex "options" "&(tls)& authenticator (server)"
+The &(tls)& authenticator has three server options:
+
+.option server_param1 tls string&!! unset
+.cindex "variables (&$auth1$& &$auth2$& etc)" "in &(tls)& authenticator"
+This option is expanded after the TLS negotiation and
+the result is placed in &$auth1$&.
+If the expansion is forced to fail, authentication fails. Any other expansion
+failure causes a temporary error code to be returned.
+
+.option server_param2 tls string&!! unset
+.option server_param3 tls string&!! unset
+As above, for &$auth2$& and &$auth3$&.
+
+&%server_param1%& may also be spelled &%server_param%&.
+
+
+Example:
+.code
+tls:
+  driver = tls
+  server_param1 =     ${certextract {subj_altname,mail,>:} \
+                                    {$tls_in_peercert}}
+  server_condition =  ${if forany {$auth1} \
+                            {!= {0} \
+                                {${lookup ldap{ldap:///\
+                         mailname=${quote_ldap_dn:${lc:$item}},\
+                         ou=users,LDAP_DC?mailid} {$value}{0} \
+                       }    }   } }
+  server_set_id =     ${if = {1}{${listcount:$auth1}} {$auth1}{}}
+.endd
+.ecindex IIDtlsauth1
+.ecindex IIDtlsauth2
+
+
+Note that because authentication is traditionally an SMTP operation,
+the &%authenticated%& ACL condition cannot be used in
+a connect- or helo-ACL.
+
+
+

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


@@ -25931,8 +26466,9 @@ include files and libraries for GnuTLS can be found.
 There are some differences in usage when using GnuTLS instead of OpenSSL:
 
 .ilist
 There are some differences in usage when using GnuTLS instead of OpenSSL:
 
 .ilist

-The &%tls_verify_certificates%& option must contain the name of a file, not the
-name of a directory for GnuTLS versions before 3.3.6
+The &%tls_verify_certificates%& option
+cannot be the path of a directory
+for GnuTLS versions before 3.3.6

 (for later versions, or OpenSSL, it can be either).
 .next
 The default value for &%tls_dhparam%& differs for historical reasons.
 (for later versions, or OpenSSL, it can be either).
 .next
 The default value for &%tls_dhparam%& differs for historical reasons.


@@ -26284,8 +26820,10 @@ 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. These must be available in a file or,
-for OpenSSL only (not GnuTLS), a directory, identified by
+expected certificates.
+These may be the system default set (depending on library version),
+an explicit file or,
+depending on library version, a directory, identified by

 &%tls_verify_certificates%&.
 
 A file can contain multiple certificates, concatenated end to end. If a
 &%tls_verify_certificates%&.
 
 A file can contain multiple certificates, concatenated end to end. If a


@@ -26359,7 +26897,9 @@ starts retrying to fetch an OCSP proof some time before its current
 proof expires.  The downside is that it requires server support.
 
 Unless Exim is built with the support disabled,
 proof expires.  The downside is that it requires server support.
 
 Unless Exim is built with the support disabled,

-or with GnuTLS earlier than version 3.1.3,
+.new
+or with GnuTLS earlier than version 3.3.16 / 3.4.8
+.wen

 support for OCSP stapling is included.
 
 There is a global option called &%tls_ocsp_file%&.
 support for OCSP stapling is included.
 
 There is a global option called &%tls_ocsp_file%&.


@@ -26445,9 +26985,13 @@ if it requests it. If the server is Exim, it will request a certificate only if
 &%tls_verify_hosts%& or &%tls_try_verify_hosts%& matches the client.
 
 If the &%tls_verify_certificates%& option is set on the &(smtp)& transport, it
 &%tls_verify_hosts%& or &%tls_try_verify_hosts%& matches the client.
 
 If the &%tls_verify_certificates%& option is set on the &(smtp)& transport, it

+specifies a collection of expected server certificates.
+These may be the system default set (depending on library version),
+a file or,
+depending on library version, a directory,

 must name a file or,
 must name a file or,

-for OpenSSL only (not GnuTLS), a directory, that contains a collection of
-expected server certificates. The client verifies the server's certificate
+for OpenSSL only (not GnuTLS), a directory.
+The client verifies the server's certificate

 against this collection, taking into account any revoked certificates that are
 in the list defined by &%tls_crl%&.
 Failure to verify fails the TLS connection unless either of the
 against this collection, taking into account any revoked certificates that are
 in the list defined by &%tls_crl%&.
 Failure to verify fails the TLS connection unless either of the


@@ -26514,7 +27058,7 @@ client in the initial handshake, so that the server can examine the servername
 within and possibly choose to use different certificates and keys (and more)
 for this session.
 
 within and possibly choose to use different certificates and keys (and more)
 for this session.
 

-This is analagous to HTTP's &"Host:"& header, and is the main mechanism by
+This is analogous to HTTP's &"Host:"& header, and is the main mechanism by

 which HTTPS-enabled web-sites can be virtual-hosted, many sites to one IP
 address.
 
 which HTTPS-enabled web-sites can be virtual-hosted, many sites to one IP
 address.
 


@@ -26568,7 +27112,7 @@ arbitrary unverified data provided prior to authentication.
 The Exim developers are proceeding cautiously and so far no other TLS options
 are re-expanded.
 
 The Exim developers are proceeding cautiously and so far no other TLS options
 are re-expanded.
 

-When Exim is built againt OpenSSL, OpenSSL must have been built with support
+When Exim is built against OpenSSL, OpenSSL must have been built with support

 for TLS Extensions.  This holds true for OpenSSL 1.0.0+ and 0.9.8+ with
 enable-tlsext in EXTRACONFIGURE.  If you invoke &(openssl s_client -h)& and
 see &`-servername`& in the output, then OpenSSL has support.
 for TLS Extensions.  This holds true for OpenSSL 1.0.0+ and 0.9.8+ with
 enable-tlsext in EXTRACONFIGURE.  If you invoke &(openssl s_client -h)& and
 see &`-servername`& in the output, then OpenSSL has support.


@@ -26758,6 +27302,7 @@ options in the main part of the configuration. These options are:
 .cindex "EXPN" "ACL for"
 .cindex "HELO" "ACL for"
 .cindex "EHLO" "ACL for"
 .cindex "EXPN" "ACL for"
 .cindex "HELO" "ACL for"
 .cindex "EHLO" "ACL for"

+.cindex "DKIM" "ACL for"

 .cindex "MAIL" "ACL for"
 .cindex "QUIT, ACL for"
 .cindex "RCPT" "ACL for"
 .cindex "MAIL" "ACL for"
 .cindex "QUIT, ACL for"
 .cindex "RCPT" "ACL for"


@@ -26776,6 +27321,7 @@ options in the main part of the configuration. These options are:
 .irow &%acl_smtp_connect%&     "ACL for start of SMTP connection"
 .irow &%acl_smtp_data%&        "ACL after DATA is complete"
 .irow &%acl_smtp_data_prdr%&   "ACL for each recipient, after DATA is complete"
 .irow &%acl_smtp_connect%&     "ACL for start of SMTP connection"
 .irow &%acl_smtp_data%&        "ACL after DATA is complete"
 .irow &%acl_smtp_data_prdr%&   "ACL for each recipient, after DATA is complete"

+.irow &%acl_smtp_dkim%&        "ACL for each DKIM signer"

 .irow &%acl_smtp_etrn%&        "ACL for ETRN"
 .irow &%acl_smtp_expn%&        "ACL for EXPN"
 .irow &%acl_smtp_helo%&        "ACL for HELO or EHLO"
 .irow &%acl_smtp_etrn%&        "ACL for ETRN"
 .irow &%acl_smtp_expn%&        "ACL for EXPN"
 .irow &%acl_smtp_helo%&        "ACL for HELO or EHLO"


@@ -26916,6 +27462,7 @@ This ACL is evaluated after &%acl_smtp_dkim%& but before &%acl_smtp_data%&.
 
 
 .section "The SMTP PRDR ACL" "SECTPRDRACL"
 
 
 .section "The SMTP PRDR ACL" "SECTPRDRACL"

+.cindex "PRDR" "ACL for"

 .oindex "&%prdr_enable%&"
 The &%acl_smtp_data_prdr%& ACL is available only when Exim is compiled
 with PRDR support enabled (which is the default).
 .oindex "&%prdr_enable%&"
 The &%acl_smtp_data_prdr%& ACL is available only when Exim is compiled
 with PRDR support enabled (which is the default).


@@ -26923,9 +27470,10 @@ It becomes active only when the PRDR feature is negotiated between
 client and server for a message, and more than one recipient
 has been accepted.
 
 client and server for a message, and more than one recipient
 has been accepted.
 

-The ACL test specfied by &%acl_smtp_data_prdr%& happens after a message
-has been recieved, and is executed for each recipient of the message.
-The test may accept or deny for inividual recipients.
+The ACL test specified by &%acl_smtp_data_prdr%& happens after a message
+has been received, and is executed once for each recipient of the message
+with &$local_part$& and &$domain$& valid.
+The test may accept, defer or deny for individual recipients.

 The &%acl_smtp_data%& will still be called after this ACL and
 can reject the message overall, even if this ACL has accepted it
 for some or all recipients.
 The &%acl_smtp_data%& will still be called after this ACL and
 can reject the message overall, even if this ACL has accepted it
 for some or all recipients.


@@ -26933,10 +27481,14 @@ for some or all recipients.
 PRDR may be used to support per-user content filtering.  Without it
 one must defer any recipient after the first that has a different
 content-filter configuration.  With PRDR, the RCPT-time check
 PRDR may be used to support per-user content filtering.  Without it
 one must defer any recipient after the first that has a different
 content-filter configuration.  With PRDR, the RCPT-time check

-for this can be disabled when the MAIL-time $smtp_command included
-"PRDR".  Any required difference in behaviour of the main DATA-time
+.new
+.cindex "PRDR" "variable for"
+for this can be disabled when the variable &$prdr_requested$&
+is &"yes"&.
+.wen
+Any required difference in behaviour of the main DATA-time

 ACL should however depend on the PRDR-time ACL having run, as Exim
 ACL should however depend on the PRDR-time ACL having run, as Exim

-will avoid doing so in some situations (eg.  single-recipient mails).
+will avoid doing so in some situations (e.g.  single-recipient mails).

 
 See also the &%prdr_enable%& global option
 and the &%hosts_try_prdr%& smtp transport option.
 
 See also the &%prdr_enable%& global option
 and the &%hosts_try_prdr%& smtp transport option.


@@ -26949,8 +27501,9 @@ the feature was not requested by the client.
 .cindex "QUIT, ACL for"
 The ACL for the SMTP QUIT command is anomalous, in that the outcome of the ACL
 does not affect the response code to QUIT, which is always 221. Thus, the ACL
 .cindex "QUIT, ACL for"
 The ACL for the SMTP QUIT command is anomalous, in that the outcome of the ACL
 does not affect the response code to QUIT, which is always 221. Thus, the ACL

-does not in fact control any access. For this reason, the only verbs that are
-permitted are &%accept%& and &%warn%&.
+does not in fact control any access.
+For this reason, it may only accept
+or warn as its final result.

 
 This ACL can be used for tasks such as custom logging at the end of an SMTP
 session. For example, you can use ACL variables in other ACLs to count
 
 This ACL can be used for tasks such as custom logging at the end of an SMTP
 session. For example, you can use ACL variables in other ACLs to count


@@ -27865,14 +28418,18 @@ is what is wanted for subsequent tests.
 .cindex "cutthrough" "requesting"
 This option requests delivery be attempted while the item is being received.
 
 .cindex "cutthrough" "requesting"
 This option requests delivery be attempted while the item is being received.
 

-The option usable in the RCPT ACL.
-If enabled for a message recieved via smtp and routed to an smtp transport,
-and the message has only one recipient,
+The option is usable in the RCPT ACL.
+If enabled for a message received via smtp and routed to an smtp transport,
+and only one transport, interface, destination host and port combination
+is used for all recipients of the message,

 then the delivery connection is made while the receiving connection is open
 and data is copied from one to the other.
 
 then the delivery connection is made while the receiving connection is open
 and data is copied from one to the other.
 

+An attempt to set this option for any recipient but the first
+for a mail will be quietly ignored.

 If a recipient-verify callout connection is subsequently
 If a recipient-verify callout connection is subsequently

-requested in the same ACL it is held open and used for the data,
+requested in the same ACL it is held open and used for
+any subsequent recipients and the data,

 otherwise one is made after the initial RCPT ACL completes.
 
 Note that routers are used in verify mode,
 otherwise one is made after the initial RCPT ACL completes.
 
 Note that routers are used in verify mode,


@@ -27884,12 +28441,13 @@ Headers may be modified by routers (subject to the above) and transports.
 Cutthrough delivery is not supported via transport-filters or when DKIM signing
 of outgoing messages is done, because it sends data to the ultimate destination
 before the entire message has been received from the source.
 Cutthrough delivery is not supported via transport-filters or when DKIM signing
 of outgoing messages is done, because it sends data to the ultimate destination
 before the entire message has been received from the source.

+It is not supported for messages received with the SMTP PRDR option in use.

 
 Should the ultimate destination system positively accept or reject the mail,
 a corresponding indication is given to the source system and nothing is queued.
 If there is a temporary error the item is queued for later delivery in the
 usual fashion. If the item is successfully delivered in cutthrough mode
 
 Should the ultimate destination system positively accept or reject the mail,
 a corresponding indication is given to the source system and nothing is queued.
 If there is a temporary error the item is queued for later delivery in the
 usual fashion. If the item is successfully delivered in cutthrough mode

-the log line is tagged with ">>" rather than "=>" and appears
+the delivery log lines are tagged with ">>" rather than "=>" and appear

 before the acceptance "<=" line.
 
 Delivery in this mode avoids the generation of a bounce mail to a
 before the acceptance "<=" line.
 
 Delivery in this mode avoids the generation of a bounce mail to a


@@ -28621,7 +29179,8 @@ This condition is relevant only in an ACL that is run after a message has been
 received, that is, in an ACL specified by &%acl_smtp_data%& or
 &%acl_not_smtp%&. It checks the syntax of all header lines that can contain
 lists of addresses (&'Sender:'&, &'From:'&, &'Reply-To:'&, &'To:'&, &'Cc:'&,
 received, that is, in an ACL specified by &%acl_smtp_data%& or
 &%acl_not_smtp%&. It checks the syntax of all header lines that can contain
 lists of addresses (&'Sender:'&, &'From:'&, &'Reply-To:'&, &'To:'&, &'Cc:'&,

-and &'Bcc:'&). Unqualified addresses (local parts without domains) are
+and &'Bcc:'&), returning true if there are no problems.
+Unqualified addresses (local parts without domains) are

 permitted only in locally generated messages and from hosts that match
 &%sender_unqualified_hosts%& or &%recipient_unqualified_hosts%&, as
 appropriate.
 permitted only in locally generated messages and from hosts that match
 &%sender_unqualified_hosts%& or &%recipient_unqualified_hosts%&, as
 appropriate.


@@ -28681,7 +29240,7 @@ verified is redirected to a single address, verification continues with the new
 address, and in that case, the subsequent value of &$address_data$& is the
 value for the child address.
 
 address, and in that case, the subsequent value of &$address_data$& is the
 value for the child address.
 

-.vitem &*verify&~=&~reverse_host_lookup*&
+.vitem &*verify&~=&~reverse_host_lookup/*&<&'options'&>

 .cindex "&%verify%& ACL condition"
 .cindex "&ACL;" "verifying host reverse lookup"
 .cindex "host" "verifying reverse lookup"
 .cindex "&%verify%& ACL condition"
 .cindex "&ACL;" "verifying host reverse lookup"
 .cindex "host" "verifying reverse lookup"


@@ -28692,6 +29251,9 @@ Verification ensures that the host name obtained from a reverse DNS lookup, or
 one of its aliases, does, when it is itself looked up in the DNS, yield the
 original IP address.
 
 one of its aliases, does, when it is itself looked up in the DNS, yield the
 original IP address.
 

+There is one possible option, &`defer_ok`&.  If this is present and a
+DNS operation returns a temporary error, the verify condition succeeds.
+

 If this condition is used for a locally generated message (that is, when there
 is no client host involved), it always succeeds.
 
 If this condition is used for a locally generated message (that is, when there
 is no client host involved), it always succeeds.
 


@@ -28780,9 +29342,15 @@ deny  dnslists = blackholes.mail-abuse.org
 warn  message  = X-Warn: sending host is on dialups list
       dnslists = dialups.mail-abuse.org
 .endd
 warn  message  = X-Warn: sending host is on dialups list
       dnslists = dialups.mail-abuse.org
 .endd

-DNS list lookups are cached by Exim for the duration of the SMTP session,
+.cindex cacheing "of dns lookup"
+.cindex DNS TTL
+DNS list lookups are cached by Exim for the duration of the SMTP session
+.new
+(but limited by the DNS return TTL value),
+.wen

 so a lookup based on the IP address is done at most once for any incoming
 so a lookup based on the IP address is done at most once for any incoming

-connection. Exim does not share information between multiple incoming
+connection (assuming long-enough TTL).
+Exim does not share information between multiple incoming

 connections (but your local name server cache should be active).
 
 
 connections (but your local name server cache should be active).
 
 


@@ -29295,7 +29863,7 @@ The &%per_rcpt%& option causes Exim to limit the rate at which recipients are
 accepted. It can be used in the &%acl_smtp_rcpt%&, &%acl_smtp_predata%&,
 &%acl_smtp_mime%&, &%acl_smtp_data%&, or &%acl_smtp_rcpt%& ACLs. In
 &%acl_smtp_rcpt%& the rate is updated one recipient at a time; in the other
 accepted. It can be used in the &%acl_smtp_rcpt%&, &%acl_smtp_predata%&,
 &%acl_smtp_mime%&, &%acl_smtp_data%&, or &%acl_smtp_rcpt%& ACLs. In
 &%acl_smtp_rcpt%& the rate is updated one recipient at a time; in the other

-ACLs the rate is updated with the total recipient count in one go. Note that
+ACLs the rate is updated with the total (accepted) recipient count in one go. Note that

 in either case the rate limiting engine will see a message with many
 recipients as a large high-speed burst.
 
 in either case the rate limiting engine will see a message with many
 recipients as a large high-speed burst.
 


@@ -30239,10 +30807,12 @@ It supports a &"generic"& interface to scanners called via the shell, and
 specialized interfaces for &"daemon"& type virus scanners, which are resident
 in memory and thus are much faster.
 
 specialized interfaces for &"daemon"& type virus scanners, which are resident
 in memory and thus are much faster.
 

+A timeout of 2 minutes is applied to a scanner call (by default);
+if it expires then a defer action is taken.

 
 .oindex "&%av_scanner%&"
 
 .oindex "&%av_scanner%&"

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

 are needed. The basic syntax is as follows:
 .display
 &`av_scanner = <`&&'scanner-type'&&`>:<`&&'option1'&&`>:<`&&'option2'&&`>:[...]`&
 are needed. The basic syntax is as follows:
 .display
 &`av_scanner = <`&&'scanner-type'&&`>:<`&&'option1'&&`>:<`&&'option2'&&`>:[...]`&


@@ -30257,6 +30827,39 @@ The usual list-parsing of the content (see &<<SECTlistconstruct>>&) applies.
 The following scanner types are supported in this release:
 
 .vlist
 The following scanner types are supported in this release:
 
 .vlist

+.vitem &%avast%&
+.cindex "virus scanners" "avast"
+This is the scanner daemon of Avast. It has been tested with Avast Core
+Security (currently at version 1.1.7).
+You can get a trial version at &url(http://www.avast.com) or for Linux
+at &url(http://www.avast.com/linux-server-antivirus).
+This scanner type takes one option,
+which can be either a full path to a UNIX socket,
+or host and port specifiers separated by white space.
+The host may be a name or an IP address; the port is either a
+single number or a pair of numbers with a dash between.
+Any further options are given, on separate lines,
+to the daemon as options before the main scan command.
+For example:
+.code
+av_scanner = avast:/var/run/avast/scan.sock:FLAGS -fullfiles:SENSITIVITY -pup
+av_scanner = avast:192.168.2.22 5036
+.endd
+If you omit the argument, the default path
+&_/var/run/avast/scan.sock_&
+is used.
+If you use a remote host,
+you need to make Exim's spool directory available to it,
+as the scanner is passed a file path, not file contents.
+For information about available commands and their options you may use
+.code
+$ socat UNIX:/var/run/avast/scan.sock STDIO:
+    FLAGS
+    SENSITIVITY
+    PACK
+.endd
+
+

 .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


@@ -30273,17 +30876,39 @@ av_scanner = aveserver:/var/run/aveserver
 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
 unpack MIME containers, so it used to be recommended to unpack MIME attachments
 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
 unpack MIME containers, so it used to be recommended to unpack MIME attachments

-in the MIME ACL. This no longer believed to be necessary. One option is
-required: either the path and name of a UNIX socket file, or a hostname or IP
-number, and a port, separated by space, as in the second of these examples:
+in the MIME ACL. This is no longer believed to be necessary.
+
+The options are a list of server specifiers, which may be
+a UNIX socket specification,
+a TCP socket specification,
+or a (global) option.
+
+A socket specification consists of a space-separated list.
+For a Unix socket the first element is a full path for the socket,
+for a TCP socket the first element is the IP address
+and the second a port number,
+Any further elements are per-server (non-global) options.
+These per-server options are supported:
+.code
+retry=<timespec>       Retry on connect fail
+.endd
+
+The &`retry`& option specifies a time after which a single retry for
+a failed connect is made.  The default is to not retry.
+
+If a Unix socket file is specified, only one server is supported.
+
+Examples:

 .code
 av_scanner = clamd:/opt/clamd/socket
 av_scanner = clamd:192.0.2.3 1234
 av_scanner = clamd:192.0.2.3 1234:local
 .code
 av_scanner = clamd:/opt/clamd/socket
 av_scanner = clamd:192.0.2.3 1234
 av_scanner = clamd:192.0.2.3 1234:local

+av_scanner = clamd:192.0.2.3 1234 retry=10s

 av_scanner = clamd:192.0.2.3 1234 : 192.0.2.4 1234
 .endd
 av_scanner = clamd:192.0.2.3 1234 : 192.0.2.4 1234
 .endd

-If the value of av_scanner points to a UNIX socket file or contains the local
-keyword, then the ClamAV interface will pass a filename containing the data
+If the value of av_scanner points to a UNIX socket file or contains the
+&`local`&
+option, then the ClamAV interface will pass a filename containing the data

 to be scanned, which will should normally result in less I/O happening and be
 more efficient.  Normally in the TCP case, the data is streamed to ClamAV as
 Exim does not assume that there is a common filesystem with the remote host.
 to be scanned, which will should normally result in less I/O happening and be
 more efficient.  Normally in the TCP case, the data is streamed to ClamAV as
 Exim does not assume that there is a common filesystem with the remote host.


@@ -30409,7 +31034,7 @@ You can safely omit this option (the default value is 1).
 This is a general-purpose way of talking to simple scanner daemons
 running on the local machine.
 There are four options:
 This is a general-purpose way of talking to simple scanner daemons
 running on the local machine.
 There are four options:

-an address (which may be an IP addres and port, or the path of a Unix socket),
+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,


@@ -30448,7 +31073,8 @@ which case each use of the &%malware%& condition causes a new scan of the
 message.
 
 The &%malware%& condition takes a right-hand argument that is expanded before
 message.
 
 The &%malware%& condition takes a right-hand argument that is expanded before

-use. It can then be one of
+use and taken as a list, slash-separated by default.
+The first element can then be one of

 
 .ilist
 &"true"&, &"*"&, or &"1"&, in which case the message is scanned for viruses.
 
 .ilist
 &"true"&, &"*"&, or &"1"&, in which case the message is scanned for viruses.


@@ -30461,11 +31087,25 @@ the condition fails immediately.
 A regular expression, in which case the message is scanned for viruses. The
 condition succeeds if a virus is found and its name matches the regular
 expression. This allows you to take special actions on certain types of virus.
 A regular expression, in which case the message is scanned for viruses. The
 condition succeeds if a virus is found and its name matches the regular
 expression. This allows you to take special actions on certain types of virus.

+Note that &"/"& characters in the RE must be doubled due to the list-processing,
+unless the separator is changed (in the usual way).

 .endlist
 
 .endlist
 

-You can append &`/defer_ok`& to the &%malware%& condition to accept messages
-even if there is a problem with the virus scanner. Otherwise, such a problem
-causes the ACL to defer.
+You can append a &`defer_ok`& element to the &%malware%& argument list to accept
+messages even if there is a problem with the virus scanner.
+Otherwise, such a problem causes the ACL to defer.
+
+You can append a &`tmo=<val>`& element to the &%malware%& argument list to
+specify a non-default timeout.  The default is two minutes.
+For example:
+.code
+malware = * / defer_ok / tmo=10s
+.endd
+A timeout causes the ACL to defer.
+
+.vindex "&$callout_address$&"
+When a connection is made to the scanner the expansion variable &$callout_address$&
+is set to record the actual address used.

 
 .vindex "&$malware_name$&"
 When a virus is found, the condition sets up an expansion variable called
 
 .vindex "&$malware_name$&"
 When a virus is found, the condition sets up an expansion variable called


@@ -30509,14 +31149,20 @@ deny message = This message contains malware ($malware_name)
 .endd
 
 
 .endd
 
 

-.section "Scanning with SpamAssassin" "SECTscanspamass"
+.section "Scanning with SpamAssassin and Rspamd" "SECTscanspamass"

 .cindex "content scanning" "for spam"
 .cindex "spam scanning"
 .cindex "SpamAssassin"
 .cindex "content scanning" "for spam"
 .cindex "spam scanning"
 .cindex "SpamAssassin"

+.cindex "Rspamd"

 The &%spam%& ACL condition calls SpamAssassin's &%spamd%& daemon to get a spam
 The &%spam%& ACL condition calls SpamAssassin's &%spamd%& daemon to get a spam

-score and a report for the message. You can get SpamAssassin at
-&url(http://www.spamassassin.org), or, if you have a working Perl
-installation, you can use CPAN by running:
+score and a report for the message.
+Support is also provided for Rspamd.
+
+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)
+
+SpamAssassin can be installed with CPAN by running:

 .code
 perl -MCPAN -e 'install Mail::SpamAssassin'
 .endd
 .code
 perl -MCPAN -e 'install Mail::SpamAssassin'
 .endd


@@ -30525,42 +31171,96 @@ documentation to see how you can tweak it. The default installation should work
 nicely, however.
 
 .oindex "&%spamd_address%&"
 nicely, however.
 
 .oindex "&%spamd_address%&"

-After having installed and configured SpamAssassin, start the &%spamd%& daemon.
-By default, it listens on 127.0.0.1, TCP port 783. If you use another host or
-port for &%spamd%&, you must set the &%spamd_address%& option in the global
-part of the Exim configuration as follows (example):
+By default, SpamAssassin listens on 127.0.0.1, TCP port 783 and if you
+intend to use an instance running on the local host you do not need to set
+&%spamd_address%&. If you intend to use another host or port for SpamAssassin,
+you must set the &%spamd_address%& option in the global part of the Exim
+configuration as follows (example):

 .code
 spamd_address = 192.168.99.45 387
 .endd
 .code
 spamd_address = 192.168.99.45 387
 .endd

-You do not need to set this option if you use the default. As of version 2.60,
-&%spamd%& also supports communication over UNIX sockets. If you want to use
-these, supply &%spamd_address%& with an absolute file name instead of a
-address/port pair:
+
+To use Rspamd (which by default listens on all local addresses
+on TCP port 11333)
+you should add &%variant=rspamd%& after the address/port pair, for example:
+.code
+spamd_address = 127.0.0.1 11333 variant=rspamd
+.endd
+
+As of version 2.60, &%SpamAssassin%& also supports communication over UNIX
+sockets. If you want to us these, supply &%spamd_address%& with an absolute
+file name instead of an address/port pair:

 .code
 spamd_address = /var/run/spamd_socket
 .endd
 You can have multiple &%spamd%& servers to improve scalability. These can
 reside on other hardware reachable over the network. To specify multiple
 &%spamd%& servers, put multiple address/port pairs in the &%spamd_address%&
 .code
 spamd_address = /var/run/spamd_socket
 .endd
 You can have multiple &%spamd%& servers to improve scalability. These can
 reside on other hardware reachable over the network. To specify multiple
 &%spamd%& servers, put multiple address/port pairs in the &%spamd_address%&

-option, separated with colons:
+option, separated with colons (the separator can be changed in the usual way):

 .code
 spamd_address = 192.168.2.10 783 : \
                 192.168.2.11 783 : \
                 192.168.2.12 783
 .endd
 .code
 spamd_address = 192.168.2.10 783 : \
                 192.168.2.11 783 : \
                 192.168.2.12 783
 .endd

-Up to 32 &%spamd%& servers are supported. The servers are queried in a random
-fashion. When a server fails to respond to the connection attempt, all other
+Up to 32 &%spamd%& servers are supported.
+When a server fails to respond to the connection attempt, all other

 servers are tried until one succeeds. If no server responds, the &%spam%&
 condition defers.
 
 servers are tried until one succeeds. If no server responds, the &%spam%&
 condition defers.
 

-&*Warning*&: It is not possible to use the UNIX socket connection method with
-multiple &%spamd%& servers.
+Unix and TCP socket specifications may be mixed in any order.
+Each element of the list is a list itself, space-separated by default
+and changeable in the usual way.
+
+For TCP socket specifications a host name or IP (v4 or v6, but
+subject to list-separator quoting rules) address can be used,
+and the port can be one or a dash-separated pair.
+In the latter case, the range is tried in strict order.
+
+Elements after the first for Unix sockets, or second for TCP socket,
+are options.
+The supported options are:
+.code
+pri=<priority>      Selection priority
+weight=<value>      Selection bias
+time=<start>-<end>  Use only between these times of day
+retry=<timespec>    Retry on connect fail
+tmo=<timespec>      Connection time limit
+variant=rspamd      Use Rspamd rather than SpamAssassin protocol
+.endd
+
+The &`pri`& option specifies a priority for the server within the list,
+higher values being tried first.
+The default priority is 1.
+
+The &`weight`& option specifies a selection bias.
+Within a priority set
+servers are queried in a random fashion, weighted by this value.
+The default value for selection bias is 1.
+
+Time specifications for the &`time`& option are <hour>.<minute>.<second>
+in the local time zone; each element being one or more digits.
+Either the seconds or both minutes and seconds, plus the leading &`.`&
+characters, may be omitted and will be taken as zero.
+
+Timeout specifications for the &`retry`& and &`tmo`& options
+are the usual Exim time interval standard, e.g. &`20s`& or &`1m`&.
+
+The &`tmo`& option specifies an overall timeout for communication.
+The default value is two minutes.
+
+The &`retry`& option specifies a time after which a single retry for
+a failed connect is made.
+The default is to not retry.

 
 The &%spamd_address%& variable is expanded before use if it starts with
 a dollar sign. In this case, the expansion may return a string that is
 used as the list so that multiple spamd servers can be the result of an
 expansion.
 
 
 The &%spamd_address%& variable is expanded before use if it starts with
 a dollar sign. In this case, the expansion may return a string that is
 used as the list so that multiple spamd servers can be the result of an
 expansion.
 

+.vindex "&$callout_address$&"
+When a connection is made to the server the expansion variable &$callout_address$&
+is set to record the actual address used.
+

 .section "Calling SpamAssassin from an Exim ACL" "SECID206"
 Here is a simple example of the use of the &%spam%& condition in a DATA ACL:
 .code
 .section "Calling SpamAssassin from an Exim ACL" "SECID206"
 Here is a simple example of the use of the &%spam%& condition in a DATA ACL:
 .code


@@ -30571,14 +31271,21 @@ The right-hand side of the &%spam%& condition specifies a name. This is
 relevant if you have set up multiple SpamAssassin profiles. If you do not want
 to scan using a specific profile, but rather use the SpamAssassin system-wide
 default profile, you can scan for an unknown name, or simply use &"nobody"&.
 relevant if you have set up multiple SpamAssassin profiles. If you do not want
 to scan using a specific profile, but rather use the SpamAssassin system-wide
 default profile, you can scan for an unknown name, or simply use &"nobody"&.

-However, you must put something on the right-hand side.
+Rspamd does not use this setting. However, you must put something on the
+right-hand side.

 
 The name allows you to use per-domain or per-user antispam profiles in
 principle, but this is not straightforward in practice, because a message may
 have multiple recipients, not necessarily all in the same domain. Because the
 
 The name allows you to use per-domain or per-user antispam profiles in
 principle, but this is not straightforward in practice, because a message may
 have multiple recipients, not necessarily all in the same domain. Because the

-&%spam%& condition has to be called from a DATA ACL in order to be able to
+&%spam%& condition has to be called from a DATA-time ACL in order to be able to

 read the contents of the message, the variables &$local_part$& and &$domain$&
 are not set.
 read the contents of the message, the variables &$local_part$& and &$domain$&
 are not set.

+Careful enforcement of single-recipient messages
+(e.g. by responding with defer in the recipient ACL for all recipients
+after the first),
+or the use of PRDR,
+.cindex "PRDR" "use for per-user SpamAssassin profiles"
+are needed to use this feature.

 
 The right-hand side of the &%spam%& condition is expanded before being used, so
 you can put lookups or conditions there. When the right-hand side evaluates to
 
 The right-hand side of the &%spam%& condition is expanded before being used, so
 you can put lookups or conditions there. When the right-hand side evaluates to


@@ -30602,7 +31309,9 @@ it always return &"true"& by appending &`:true`& to the username.
 
 .cindex "spam scanning" "returned variables"
 When the &%spam%& condition is run, it sets up a number of expansion
 
 .cindex "spam scanning" "returned variables"
 When the &%spam%& condition is run, it sets up a number of expansion

-variables. These variables are saved with the received message, thus they are
+variables.
+Except for &$spam_report$&,
+these variables are saved with the received message so are

 available for use at delivery time.
 
 .vlist
 available for use at delivery time.
 
 .vlist


@@ -30620,11 +31329,19 @@ The integer value is useful for numeric comparisons in conditions.
 A string consisting of a number of &"+"& or &"-"& characters, representing the
 integer part of the spam score value. A spam score of 4.4 would have a
 &$spam_bar$& value of &"++++"&. This is useful for inclusion in warning
 A string consisting of a number of &"+"& or &"-"& characters, representing the
 integer part of the spam score value. A spam score of 4.4 would have a
 &$spam_bar$& value of &"++++"&. This is useful for inclusion in warning

-headers, since MUAs can match on such strings.
+headers, since MUAs can match on such strings. The maximum length of the
+spam bar is 50 characters.

 
 .vitem &$spam_report$&
 A multiline text table, containing the full SpamAssassin report for the
 message. Useful for inclusion in headers or reject messages.
 
 .vitem &$spam_report$&
 A multiline text table, containing the full SpamAssassin report for the
 message. Useful for inclusion in headers or reject messages.

+This variable is only usable in a DATA-time ACL.
+
+.vitem &$spam_action$&
+For SpamAssassin either 'reject' or 'no action' depending on the
+spam score versus threshold.
+For Rspamd, the recommended action.
+

 .endlist
 
 The &%spam%& condition caches its results unless expansion in
 .endlist
 
 The &%spam%& condition caches its results unless expansion in


@@ -30810,7 +31527,10 @@ containing the decoded data.
 This is perhaps the most important of the MIME variables. It contains a
 proposed filename for an attachment, if one was found in either the
 &'Content-Type:'& or &'Content-Disposition:'& headers. The filename will be
 This is perhaps the most important of the MIME variables. It contains a
 proposed filename for an attachment, if one was found in either the
 &'Content-Type:'& or &'Content-Disposition:'& headers. The filename will be

-RFC2047 decoded, but no additional sanity checks are done. If no filename was
+RFC2047
+or RFC2231
+decoded, but no additional sanity checks are done.
+ If no filename was

 found, this variable contains the empty string.
 
 .vitem &$mime_is_coverletter$&
 found, this variable contains the empty string.
 
 .vitem &$mime_is_coverletter$&


@@ -30899,6 +31619,8 @@ deny message = contains blacklisted regex ($regex_match_string)
 The conditions returns true if any one of the regular expressions matches. The
 &$regex_match_string$& expansion variable is then set up and contains the
 matching regular expression.
 The conditions returns true if any one of the regular expressions matches. The
 &$regex_match_string$& expansion variable is then set up and contains the
 matching regular expression.

+The expansion variables &$regex1$& &$regex2$& etc
+are set to any substrings captured by the regular expression.

 
 &*Warning*&: With large messages, these conditions can be fairly
 CPU-intensive.
 
 &*Warning*&: With large messages, these conditions can be fairly
 CPU-intensive.


@@ -33408,13 +34130,8 @@ failing addresses with their error messages.
 The third item is used to introduce any text from pipe transports that is to be
 returned to the sender. It is omitted if there is no such text.
 .next
 The third item is used to introduce any text from pipe transports that is to be
 returned to the sender. It is omitted if there is no such text.
 .next

-The fourth item is used to introduce the copy of the message that is returned
-as part of the error report.
-.next
-The fifth item is added after the fourth one if the returned message is
-truncated because it is bigger than &%return_size_limit%&.
-.next
-The sixth item is added after the copy of the original message.
+The fourth, fifth and sixth items will be ignored and may be empty.
+The fields exist for back-compatibility

 .endlist
 
 The default state (&%bounce_message_file%& unset) is equivalent to the
 .endlist
 
 The default state (&%bounce_message_file%& unset) is equivalent to the


@@ -34251,8 +34968,9 @@ equivalent to the setting:
 .code
 log_file_path = $spool_directory/log/%slog
 .endd
 .code
 log_file_path = $spool_directory/log/%slog
 .endd

-If you do not specify anything at build time or run time, that is where the
-logs are written.
+If you do not specify anything at build time or run time,
+or if you unset the option at run time (i.e. &`log_file_path = `&),
+that is where the logs are written.

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


@@ -34521,7 +35239,7 @@ data when a message is received. See section &<<SECTlogselector>>& below.
 .cindex "log" "delivery line"
 The format of the single-line entry in the main log that is written for every
 delivery is shown in one of the examples below, for local and remote
 .cindex "log" "delivery line"
 The format of the single-line entry in the main log that is written for every
 delivery is shown in one of the examples below, for local and remote

-deliveries, respectively. Each example has been split into two lines in order
+deliveries, respectively. Each example has been split into multiple lines in order

 to fit it on the page:
 .code
 2002-10-31 08:59:13 16ZCW1-0005MB-00 => marv
 to fit it on the page:
 .code
 2002-10-31 08:59:13 16ZCW1-0005MB-00 => marv


@@ -34752,14 +35470,20 @@ selection marked by asterisks:
 &`*etrn                       `&  ETRN commands
 &`*host_lookup_failed         `&  as it says
 &` ident_timeout              `&  timeout for ident connection
 &`*etrn                       `&  ETRN commands
 &`*host_lookup_failed         `&  as it says
 &` ident_timeout              `&  timeout for ident connection

-&` incoming_interface         `&  incoming interface on <= lines
-&` incoming_port              `&  incoming port on <= lines
+&` incoming_interface         `&  local interface on <= and => lines
+&` incoming_port              `&  remote port on <= lines

 &`*lost_incoming_connection   `&  as it says (includes timeouts)
 &`*lost_incoming_connection   `&  as it says (includes timeouts)

+.new
+&` outgoing_interface         `&  local interface on => lines
+.wen

 &` outgoing_port              `&  add remote port to => lines
 &`*queue_run                  `&  start and end queue runs
 &` queue_time                 `&  time on queue for one recipient
 &` queue_time_overall         `&  time on queue for whole message
 &` pid                        `&  Exim process id
 &` outgoing_port              `&  add remote port to => lines
 &`*queue_run                  `&  start and end queue runs
 &` queue_time                 `&  time on queue for one recipient
 &` queue_time_overall         `&  time on queue for whole message
 &` pid                        `&  Exim process id

+.new
+&` proxy                      `&  proxy address on <= and => lines
+.wen

 &` received_recipients        `&  recipients on <= lines
 &` received_sender            `&  sender on <= lines
 &`*rejected_header            `&  header contents on reject log
 &` received_recipients        `&  recipients on <= lines
 &` received_sender            `&  sender on <= lines
 &`*rejected_header            `&  header contents on reject log


@@ -34770,14 +35494,14 @@ selection marked by asterisks:
 &`*size_reject                `&  rejection because too big
 &`*skip_delivery              `&  delivery skipped in a queue run
 &`*smtp_confirmation          `&  SMTP confirmation on => lines
 &`*size_reject                `&  rejection because too big
 &`*skip_delivery              `&  delivery skipped in a queue run
 &`*smtp_confirmation          `&  SMTP confirmation on => lines

-&` smtp_connection            `&  SMTP connections
+&` smtp_connection            `&  incoming SMTP connections

 &` smtp_incomplete_transaction`&  incomplete SMTP transactions
 &` smtp_mailauth              `&  AUTH argument to MAIL commands
 &` smtp_no_mail               `&  session with no MAIL commands
 &` smtp_protocol_error        `&  SMTP protocol errors
 &` smtp_syntax_error          `&  SMTP syntax errors
 &` subject                    `&  contents of &'Subject:'& on <= lines
 &` smtp_incomplete_transaction`&  incomplete SMTP transactions
 &` smtp_mailauth              `&  AUTH argument to MAIL commands
 &` smtp_no_mail               `&  session with no MAIL commands
 &` smtp_protocol_error        `&  SMTP protocol errors
 &` smtp_syntax_error          `&  SMTP syntax errors
 &` subject                    `&  contents of &'Subject:'& on <= lines

-&` tls_certificate_verified   `&  certificate verification status
+&`*tls_certificate_verified   `&  certificate verification status

 &`*tls_cipher                 `&  TLS cipher suite on <= and => lines
 &` tls_peerdn                 `&  TLS peer DN on <= and => lines
 &` tls_sni                    `&  TLS SNI on <= lines
 &`*tls_cipher                 `&  TLS cipher suite on <= and => lines
 &` tls_peerdn                 `&  TLS peer DN on <= and => lines
 &` tls_sni                    `&  TLS SNI on <= lines


@@ -34785,6 +35509,9 @@ selection marked by asterisks:
 
 &` all                        `&  all of the above
 .endd
 
 &` all                        `&  all of the above
 .endd

+See also the &%slow_lookup_log%& main configuration option,
+section &<<SECID99>>&
+

 More details on each of these items follows:
 
 .ilist
 More details on each of these items follows:
 
 .ilist


@@ -34870,12 +35597,29 @@ routing email addresses, but it does apply to &"byname"& lookups.
 client's ident port times out.
 .next
 .cindex "log" "incoming interface"
 client's ident port times out.
 .next
 .cindex "log" "incoming interface"

+.cindex "log" "local interface"
+.cindex "log" "local address and port"
+.cindex "TCP/IP" "logging local address and port"

 .cindex "interface" "logging"
 &%incoming_interface%&: The interface on which a message was received is added
 to the &"<="& line as an IP address in square brackets, tagged by I= and
 followed by a colon and the port number. The local interface and port are also
 .cindex "interface" "logging"
 &%incoming_interface%&: The interface on which a message was received is added
 to the &"<="& line as an IP address in square brackets, tagged by I= and
 followed by a colon and the port number. The local interface and port are also

-added to other SMTP log lines, for example &"SMTP connection from"&, and to
-rejection lines.
+added to other SMTP log lines, for example &"SMTP connection from"&, to
+rejection lines, and (despite the name) to outgoing &"=>"& and &"->"& lines.
+.new
+The latter can be disabled by turning off the &%outgoing_interface%& option.
+.wen
+.next
+.new
+.cindex log "incoming proxy address"
+.cindex proxy "logging proxy address"
+.cindex "TCP/IP" "logging proxy address"
+&%proxy%&: The internal (closest to the system running Exim) IP address
+of the proxy, tagged by PRX=, on the &"<="& line for a message accepted
+on a proxied connection
+or the &"=>"& line for a message delivered on a proxied connection..
+See &<<SECTproxyInbound>>& for more information.
+.wen

 .next
 .cindex "log" "incoming remote port"
 .cindex "port" "logging remote"
 .next
 .cindex "log" "incoming remote port"
 .cindex "port" "logging remote"


@@ -34893,13 +35637,30 @@ 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

+.cindex "log" "outgoing interface"
+.cindex "log" "local interface"
+.cindex "log" "local address and port"
+.cindex "TCP/IP" "logging local address and port"
+.cindex "interface" "logging"
+.new
+&%outgoing_interface%&: If &%incoming_interface%& is turned on, then the
+interface on which a message was sent is added to delivery lines as an I= tag
+followed by IP address in square brackets. You can disable this by turning
+off the &%outgoing_interface%& option.
+.wen
+.next

 .cindex "log" "outgoing remote port"
 .cindex "port" "logging outgoint remote"
 .cindex "TCP/IP" "logging ougtoing remote port"
 &%outgoing_port%&: The remote port number is added to delivery log lines (those
 .cindex "log" "outgoing remote port"
 .cindex "port" "logging outgoint remote"
 .cindex "TCP/IP" "logging ougtoing remote port"
 &%outgoing_port%&: The remote port number is added to delivery log lines (those

-containing => tags) following the IP address. This option is not included in
-the default setting, because for most ordinary configurations, the remote port
-number is always 25 (the SMTP port).
+containing => tags) following the IP address.
+.new
+The local port is also added if &%incoming_interface%& and
+&%outgoing_interface%& are both enabled.
+.wen
+This option is not included in the default setting, because for most ordinary
+configurations, the remote port number is always 25 (the SMTP port), and the
+local port is a random ephemeral port.

 .next
 .cindex "log" "process ids in"
 .cindex "pid (process id)" "in log lines"
 .next
 .cindex "log" "process ids in"
 .cindex "pid (process id)" "in log lines"


@@ -34990,7 +35751,7 @@ response.
 .next
 .cindex "log" "SMTP connections"
 .cindex "SMTP" "logging connections"
 .next
 .cindex "log" "SMTP connections"
 .cindex "SMTP" "logging connections"

-&%smtp_connection%&: A log line is written whenever an SMTP connection is
+&%smtp_connection%&: A log line is written whenever an incoming SMTP connection is

 established or closed, unless the connection is from a host that matches
 &%hosts_connection_nolog%&. (In contrast, &%lost_incoming_connection%& applies
 only when the closure is unexpected.) This applies to connections from local
 established or closed, unless the connection is from a host that matches
 &%hosts_connection_nolog%&. (In contrast, &%lost_incoming_connection%& applies
 only when the closure is unexpected.) This applies to connections from local


@@ -35039,7 +35800,7 @@ C=EHLO,QUIT
 shows that the client issued QUIT straight after EHLO. If there were fewer
 than 20 commands, they are all listed. If there were more than 20 commands,
 the last 20 are listed, preceded by &"..."&. However, with the default
 shows that the client issued QUIT straight after EHLO. If there were fewer
 than 20 commands, they are all listed. If there were more than 20 commands,
 the last 20 are listed, preceded by &"..."&. However, with the default

-setting of 10 for &%smtp_accep_max_nonmail%&, the connection will in any case
+setting of 10 for &%smtp_accept_max_nonmail%&, the connection will in any case

 have been aborted before 20 non-mail commands are processed.
 .next
 &%smtp_mailauth%&: A third subfield with the authenticated sender,
 have been aborted before 20 non-mail commands are processed.
 .next
 &%smtp_mailauth%&: A third subfield with the authenticated sender,


@@ -35219,7 +35980,7 @@ exim -bp
 The &*-C*& option is used to specify an alternate &_exim.conf_& which might
 contain alternate exim configuration the queue management might be using.
 
 The &*-C*& option is used to specify an alternate &_exim.conf_& which might
 contain alternate exim configuration the queue management might be using.
 

-to obtain a queue listing, and then greps the output to select messages 
+to obtain a queue listing, and then greps the output to select messages

 that match given criteria. The following selection options are available:
 
 .vlist
 that match given criteria. The following selection options are available:
 
 .vlist


@@ -35230,7 +35991,7 @@ tested is enclosed in angle brackets, so you can test for bounce messages with
 exiqgrep -f '^<>$'
 .endd
 .vitem &*-r*&&~<&'regex'&>
 exiqgrep -f '^<>$'
 .endd
 .vitem &*-r*&&~<&'regex'&>

-Match a recipient address using a case-insensitve search. The field that is
+Match a recipient address using a case-insensitive search. The field that is

 tested is not enclosed in angle brackets.
 
 .vitem &*-s*&&~<&'regex'&>
 tested is not enclosed in angle brackets.
 
 .vitem &*-s*&&~<&'regex'&>


@@ -35362,6 +36123,8 @@ search term.
 If the location of a &'zcat'& command is known from the definition of
 ZCAT_COMMAND in &_Local/Makefile_&, &'exigrep'& automatically passes any file
 whose name ends in COMPRESS_SUFFIX through &'zcat'& as it searches it.
 If the location of a &'zcat'& command is known from the definition of
 ZCAT_COMMAND in &_Local/Makefile_&, &'exigrep'& automatically passes any file
 whose name ends in COMPRESS_SUFFIX through &'zcat'& as it searches it.

+If the ZCAT_COMMAND is not executable, &'exigrep'& tries to use
+autodetection of some well known compression extensions.

 
 
 .section "Selecting messages by various criteria (exipick)" "SECTexipick"
 
 
 .section "Selecting messages by various criteria (exipick)" "SECTexipick"


@@ -35641,6 +36404,9 @@ Serializing ETRN runs (when &%smtp_etrn_serialize%& is set)
 .next
 Serializing delivery to a specific host (when &%serialize_hosts%& is set in an
 &(smtp)& transport)
 .next
 Serializing delivery to a specific host (when &%serialize_hosts%& is set in an
 &(smtp)& transport)

+.next
+Limiting the concurrency of specific transports (when &%max_parallel%& is set
+in a transport)

 .endlist
 
 
 .endlist
 
 


@@ -36501,7 +37267,7 @@ Such invocations should be viewed with prejudicial suspicion.
 Administrators who use embedded Perl are advised to explore how Perl's
 taint checking might apply to their usage.
 .next
 Administrators who use embedded Perl are advised to explore how Perl's
 taint checking might apply to their usage.
 .next

-Use of &%${expand...}%& is somewhat analagous to shell's eval builtin and
+Use of &%${expand...}%& is somewhat analogous to shell's eval builtin and

 administrators are well advised to view its use with suspicion, in case (for
 instance) it allows a local-part to contain embedded Exim directives.
 .next
 administrators are well advised to view its use with suspicion, in case (for
 instance) it allows a local-part to contain embedded Exim directives.
 .next


@@ -37116,7 +37882,7 @@ Verification of DKIM signatures in incoming email is implemented via the
 &%acl_smtp_dkim%& ACL. By default, this ACL is called once for each
 syntactically(!) correct signature in the incoming message.
 A missing ACL definition defaults to accept.
 &%acl_smtp_dkim%& ACL. By default, this ACL is called once for each
 syntactically(!) correct signature in the incoming message.
 A missing ACL definition defaults to accept.

-If any ACL call does not acccept, the message is not accepted.
+If any ACL call does not accept, the message is not accepted.

 If a cutthrough delivery was in progress for the message it is
 summarily dropped (having wasted the transmission effort).
 
 If a cutthrough delivery was in progress for the message it is
 summarily dropped (having wasted the transmission effort).
 


@@ -37180,7 +37946,7 @@ available in &%$dkim_verify_reason%&.
 &%pass%&: The signature passed verification. It is valid.
 .endlist
 .vitem &%$dkim_verify_reason%&
 &%pass%&: The signature passed verification. It is valid.
 .endlist
 .vitem &%$dkim_verify_reason%&

-A string giving a litte bit more detail when &%$dkim_verify_status%& is either
+A string giving a little bit more detail when &%$dkim_verify_status%& is either

 "fail" or "invalid". One of
 .ilist
 &%pubkey_unavailable%& (when &%$dkim_verify_status%&="invalid"): The public
 "fail" or "invalid". One of
 .ilist
 &%pubkey_unavailable%& (when &%$dkim_verify_status%&="invalid"): The public


@@ -37243,6 +38009,8 @@ Key granularity (tag g=) from the key record. Defaults to "*" if not specified
 in the key record.
 .vitem &%$dkim_key_notes%&
 Notes from the key record (tag n=).
 in the key record.
 .vitem &%$dkim_key_notes%&
 Notes from the key record (tag n=).

+.vitem &%$dkim_key_length%&
+Number of bits in the key.

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


@@ -37282,6 +38050,154 @@ for more information of what they mean.
 . ////////////////////////////////////////////////////////////////////////////
 . ////////////////////////////////////////////////////////////////////////////
 
 . ////////////////////////////////////////////////////////////////////////////
 . ////////////////////////////////////////////////////////////////////////////
 

+.chapter "Proxies" "CHAPproxies" &&&
+         "Proxy support"
+.cindex "proxy support"
+.cindex "proxy" "access via"
+
+.new
+A proxy is an intermediate system through which communication is passed.
+Proxies may provide a security, availability or load-distribution function.
+
+
+.section "Inbound proxies" SECTproxyInbound
+.cindex proxy inbound
+.cindex proxy "server side"
+.cindex proxy "Proxy protocol"
+.cindex "Proxy protocol" proxy
+
+Exim has support for receiving inbound SMTP connections via a proxy
+that uses &"Proxy Protocol"& to speak to it.
+To include this support, include &"SUPPORT_PROXY=yes"&
+in Local/Makefile.
+
+It was built on specifications from:
+http://haproxy.1wt.eu/download/1.5/doc/proxy-protocol.txt
+That URL was revised in May 2014 to version 2 spec:
+http://git.1wt.eu/web?p=haproxy.git;a=commitdiff;h=afb768340c9d7e50d8e
+
+The purpose of this facility is so that an application load balancer,
+such as HAProxy, can sit in front of several Exim servers
+to distribute load.
+Exim uses the local protocol communication with the proxy to obtain
+the remote SMTP system IP address and port information.
+There is no logging if a host passes or
+fails Proxy Protocol negotiation, but it can easily be determined and
+recorded in an ACL (example is below).
+
+Use of a proxy is enabled by setting the &%hosts_proxy%&
+main configuration option to a hostlist; connections from these
+hosts will use Proxy Protocol.
+
+The following expansion variables are usable
+(&"internal"& and &"external"& here refer to the interfaces
+of the proxy):
+.display
+&'proxy_host_address   '& internal IP address of the proxy
+&'proxy_host_port      '& internal TCP port of the proxy
+&'proxy_target_address '& external IP address of the proxy
+&'proxy_target_port    '& external TCP port of the proxy
+&'proxy_session        '& boolean: SMTP connection via proxy
+.endd
+If &$proxy_session$& is set but &$proxy_host_address$& is empty
+there was a protocol error.
+
+Since the real connections are all coming from the proxy, and the
+per host connection tracking is done before Proxy Protocol is
+evaluated, &%smtp_accept_max_per_host%& must be set high enough to
+handle all of the parallel volume you expect per inbound proxy.
+With the option set so high, you lose the ability
+to protect your server from many connections from one IP.
+In order to prevent your server from overload, you
+need to add a per connection ratelimit to your connect ACL.
+A possible solution is:
+.display
+  # Set max number of connections per host
+  LIMIT   = 5
+  # Or do some kind of IP lookup in a flat file or database
+  # LIMIT = ${lookup{$sender_host_address}iplsearch{/etc/exim/proxy_limits}}
+
+  defer   message        = Too many connections from this IP right now
+          ratelimit      = LIMIT / 5s / per_conn / strict
+.endd
+
+
+
+.section "Outbound proxies" SECTproxySOCKS
+.cindex proxy outbound
+.cindex proxy "client side"
+.cindex proxy SOCKS
+.cindex SOCKS proxy
+Exim has support for sending outbound SMTP via a proxy
+using a protocol called SOCKS5 (defined by RFC1928).
+The support can be optionally included by defining SUPPORT_SOCKS=yes in
+Local/Makefile.
+
+Use of a proxy is enabled by setting the &%socks_proxy%& option
+on an smtp transport.
+The option value is expanded and should then be a list
+(colon-separated by default) of proxy specifiers.
+Each proxy specifier is a list
+(space-separated by default) where the initial element
+is an IP address and any subsequent elements are options.
+
+Options are a string <name>=<value>. 
+The list of options is in the following table:
+.display
+&`auth   `& authentication method
+&`name   `& authentication username
+&`pass   `& authentication password
+&`port   `& tcp port
+&`tmo    `& connection timeout
+&`pri    `& priority
+&`weight `& selection bias
+.endd
+
+More details on each of these options follows:
+
+.ilist
+.cindex authentication "to proxy"
+.cindex proxy authentication
+&%auth%&: Either &"none"& (default) or &"name"&.
+Using &"name"& selects username/password authentication per RFC 1929
+for access to the proxy.
+Default is &"none"&.
+.next
+&%name%&: sets the username for the &"name"& authentication method.
+Default is empty.
+.next
+&%pass%&: sets the password for the &"name"& authentication method.
+Default is empty.
+.next
+&%port%&: the TCP port number to use for the connection to the proxy.
+Default is 1080.
+.next
+&%tmo%&: sets a connection timeout in seconds for this proxy.
+Default is 5.
+.next
+&%pri%&: specifies a priority for the proxy within the list,
+higher values being tried first.
+The default priority is 1.
+.next
+&%weight%&: specifies a selection bias.
+Within a priority set servers are queried in a random fashion,
+weighted by this value.
+The default value for selection bias is 1.
+.endlist
+
+Proxies from the list are tried according to their priority
+and weight settings until one responds.  The timeout for the
+overall connection applies to the set of proxied attempts.
+
+.section Logging SECTproxyLog
+To log the (local) IP of a proxy in the incoming or delivery logline,
+add &"+proxy"& to the &%log_selector%& option.
+This will add a component tagged with &"PRX="& to the line.
+.wen
+
+. ////////////////////////////////////////////////////////////////////////////
+. ////////////////////////////////////////////////////////////////////////////
+

 .chapter "Adding new drivers or lookup types" "CHID13" &&&
          "Adding drivers or lookups"
 .cindex "adding drivers"
 .chapter "Adding new drivers or lookup types" "CHID13" &&&
          "Adding drivers or lookups"
 .cindex "adding drivers"