.set I " "
.macro copyyear
-2014
+2015
.endmacro
. /////////////////////////////////////////////////////////////////////////////
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+withdrawn.
.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
&`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
.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.
-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,
-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
${lookup dnsdb{>\n,: txt=a.b.example}}
It is permitted to specify a space as the separator character. Further
white space is ignored.
+.cindex "SOA record" "in &(dnsdb)& lookup"
+For an SOA lookup, while no result is obtained the lookup is redone with
+successively more leading components dropped from the given domain.
+Only the primary-nameserver field is returned unless a field separator is
+specified.
+.code
+${lookup dnsdb{>:,; soa=a.b.example.com}}
+.endd
+
.section "Dnsdb lookup modifiers" "SECTdnsdb_mod"
.cindex "dnsdb modifiers"
.cindex "modifiers" "dnsdb"
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
+(eg &"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%&.
+
.section "Pseudo dnsdb record types" "SECID66"
.cindex "MX record" "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
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).
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 &*${sort{*&<&'string'&>&*}{*&<&'comparator'&>&*}{*&<&'extractor'&>&*}}*&
-.cindex sorting a list
+.cindex sorting "a list"
.cindex list sorting
+.cindex expansion "list sorting"
After expansion, <&'string'&> is interpreted as a list, colon-separated by
default, but the separator can be changed in the usual way.
The <&'comparator'&> argument is interpreted as the operator
.endd
sorts a list of numbers, and
.code
-${sort {$lookup dnsdb{>:,,mx=example.com}} {<} {${listextract{1}{<,$item}}}}
+${sort {${lookup dnsdb{>:,,mx=example.com}}} {<} {${listextract{1}{<,$item}}}}
.endd
will sort an MX lookup into priority order.
.new
.vitem &$exim_version$&
-.vindex "&$exim_uid$&"
+.vindex "&$exim_version$&"
This variable contains the version string of the Exim build.
The first character is a major version number, currently 4.
Then after a dot, the next group of digits is a minor version number.
.vindex "&$lookup_dnssec_authenticated$&"
This variable is set after a DNS lookup done by
a dnsdb lookup expansion, dnslookup router or smtp transport.
+.cindex "DNS" "DNSSEC"
It will be empty if &(DNSSEC)& was not requested,
&"no"& if the result was not labelled as authenticated data
and &"yes"& if it was.
the argument of a HELO or EHLO command. This is omitted if it is identical to
the verified host name or to the host's IP address in square brackets.
+.new
+.vitem &$sender_helo_dnssec$&
+.vindex "&$sender_helo_dnssec$&"
+This boolean variable is true if a successful HELO verification was
+.cindex "DNS" "DNSSEC"
+done using DNS information the resolver library stated was authenticatied data.
+.wen
+
.vitem &$sender_helo_name$&
.vindex "&$sender_helo_name$&"
When a message is received from a remote host that has issued a HELO or EHLO
If an attempt to populate &$sender_host_name$& has been made
(by reference, &%hosts_lookup%& or
otherwise) then this boolean will have been set true if, and only if, the
-resolver library states that the reverse DNS was authenticated data. At all
+resolver library states that both
+the reverse and forward DNS were authenticated data. At all
other times, this variable is false.
+.cindex "DNS" "DNSSEC"
It is likely that you will need to coerce DNSSEC support on in the resolver
library, by setting:
.code
Exim does not perform DNSSEC validation itself, instead leaving that to a
validating resolver (eg, unbound, or bind with suitable configuration).
-Exim does not (currently) check to see if the forward DNS was also secured
-with DNSSEC, only the reverse DNS.
-
If you have changed &%host_lookup_order%& so that &`bydns`& is not the first
mechanism in the list, then this variable will be false.
It is only useful as the argument of a
&%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator,
or a &%def%& condition.
+If certificate verification fails it may refer to a failing chain element
+which is not the leaf.
.vitem &$tls_out_ourcert$&
.vindex "&$tls_out_ourcert$&"
outbound connection. It is only useful as the argument of a
&%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator,
or a &%def%& condition.
+If certificate verification fails it may refer to a failing chain element
+which is not the leaf.
.vitem &$tls_in_certificate_verified$&
.vindex "&$tls_in_certificate_verified$&"
connection, and Exim is configured to request a certificate from the client,
the value of the Distinguished Name of the certificate is made available in the
&$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$& variable refers to the inbound side
except when used in the context of an outbound SMTP delivery, when it refers to
connection, and Exim is configured to request a certificate from the server,
the value of the Distinguished Name of the certificate is made available in the
&$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$&"
.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 &%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"
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 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
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
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.
+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"
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
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
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
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
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 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,
+.new
+newline-separated (by default, changeable in the usual way),
+.wen
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
.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,
+.new
+colon-separated (by default, changeable in the usual way),
+.wen
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
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
-.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 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,
+.new
+newline-separated (by default, changeable in the usual way),
+.wen
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
.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,
+.new
+colon-separated (by default, changeable in the usual way);
+.wen
these headers are omitted from the message as it is transported, as described
in section &<<SECTheadersaddrem>>&. Header removal can also be specified by
routers.
.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.
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.
+This applies to all of the SRV, MX, AAAA, A lookup sequence.
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&!!" *
+.new
+.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.
-Note that the default is to not use TLS.
+.wen
.option hosts_max_try smtp integer 5
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.
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
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
+. ////////////////////////////////////////////////////////////////////////////
+. ////////////////////////////////////////////////////////////////////////////
+
+.new
+.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 suthentication 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
+.wen
+
+
+Note that because authentication is traditionally an SMTP operation,
+the &%authenticated%& ACL condition cannot be used in
+a connect- or helo-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
.cindex "cutthrough" "requesting"
This option requests delivery be attempted while the item is being received.
-The option usable in the RCPT ACL.
+The option is 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,
+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.
+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
-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 receipients and the data,
otherwise one is made after the initial RCPT ACL completes.
Note that routers are used in verify mode,
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 recieved 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
-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
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"
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.
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
+av_scanner = clamd:192.0.2.3 1234 retry=10s
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.
.endd
-.section "Scanning with SpamAssassin" "SECTscanspamass"
+.section "Scanning with SpamAssassin and Rspamd" "SECTscanspamass"
.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
-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.
+.new
+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)
+.wen
+
+SpamAssassin can be installed with CPAN by running:
.code
perl -MCPAN -e 'install Mail::SpamAssassin'
.endd
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
-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:
+
+.new
+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
+.wen
+
+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%&
-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
-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.
-&*Warning*&: It is not possible to use the UNIX socket connection method with
-multiple &%spamd%& servers.
+.new
+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 option 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 deafult 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, eg. &`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.
+.wen
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
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.
+.new
+Rspamd does not use this setting. However, you must put something on the
+right-hand side.
+.wen
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
&%spam%& condition has to be called from a DATA ACL in order to be able to
read the contents of the message, the variables &$local_part$& and &$domain$&
are not set.
+Careful enforcement of single-recipient messages
+(eg. 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
.vitem &$spam_report$&
A multiline text table, containing the full SpamAssassin report for the
message. Useful for inclusion in headers or reject messages.
+
+.new
+.vitem &$spam_action$&
+For SpamAssassin either 'reject' or 'no action' depending on the
+spam score versus threshold.
+For Rspamd, the recommended action.
+.wen
+
.endlist
The &%spam%& condition caches its results unless expansion in
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 &$mime_is_coverletter$&
.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.
&`*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)
&` outgoing_port `& add remote port to => lines
&`*queue_run `& start and end queue runs
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
-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"& and to
+rejection lines
+and (despite the name) the local interface is added to &"=>"& lines..
.next
.cindex "log" "incoming remote port"
.cindex "port" "logging remote"
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"
git://git.exim.org / users / heiko / exim.git / blobdiff