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
.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.
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'&>
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 &(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
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
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
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"
.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
-<&'hostname'&>::<&'port'&>(<&'socket name'&>)/<&'database'&>/&&&
- <&'user'&>/<&'password'&>
+<&'hostname'&>::<&'port'&>(<&'socket name'&>)[<&'option group'&>]/&&&
+ <&'database'&>/<&'user'&>/<&'password'&>
.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 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
condition = ${if >{$acl_m4}{3}}
.endd
+
+
+.new
+.vitem &*${imapfolder{*&<&'foldername'&>&*}}*&
+.cindex expansion "imap folder"
+.cindex "&%imapfolder%& expansion item"
+This item converts a (possibly multilevel, or with non-ASCII characters)
+folder specification to a Maildir name for filesystem use.
+For information on internationalisation support see &<<SECTi18nMDA>>&.
+.wen
+
+
+
.vitem &*${length{*&<&'string1'&>&*}{*&<&'string2'&>&*}}*&
.cindex "expansion" "string truncation"
.cindex "&%length%& expansion item"
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 &*${lc:*&<&'string'&>&*}*&
.cindex "case forcing in strings"
.cindex "string" "case forcing"
This operator encodes text according to the rules of RFC 2047. This is an
encoding that is used in header lines to encode non-ASCII characters. It is
assumed that the input string is in the encoding specified by the
-&%headers_charset%& option, which defaults to ISO-8859-1. If the string
+&%headers_charset%& option, which gets its default at build time. If the string
contains only characters in the range 33&--126, and no instances of the
characters
.code
.cindex "expansion" "utf-8 forcing"
.cindex "&%utf8clean%& expansion item"
This replaces any invalid utf-8 sequence in the string by the character &`?`&.
+
+.new
+.vitem "&*${utf8_domain_to_alabel:*&<&'string'&>&*}*&" &&&
+ "&*${utf8_domain_from_alabel:*&<&'string'&>&*}*&" &&&
+ "&*${utf8_localpart_to_alabel:*&<&'string'&>&*}*&" &&&
+ "&*${utf8_localpart_from_alabel:*&<&'string'&>&*}*&"
+.cindex expansion UTF-8
+.cindex UTF-8 expansion
+.cindex EAI
+.cindex internationalisation
+.cindex "&%utf8_domain_to_alabel%& expansion item"
+.cindex "&%utf8_domain_from_alabel%& expansion item"
+.cindex "&%utf8_localpart_to_alabel%& expansion item"
+.cindex "&%utf8_localpart_from_alabel%& expansion item"
+These convert EAI mail name components between UTF-8 and a-label forms.
+For information on internationalisation support see &<<SECTi18nMTA>>&.
+.wen
.endlist
&$dkim_key_nosubdomains$& &&&
&$dkim_key_srvtype$& &&&
&$dkim_key_granularity$& &&&
- &$dkim_key_notes$&
+ &$dkim_key_notes$& &&&
+ &$dkim_key_length$&
These variables are only available within the DKIM ACL.
For details see chapter &<<CHAPdkim>>&.
qualified host name. See also &$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
.section "Logging" "SECID99"
.table2
+.row &%event_action%& "custom logging"
.row &%hosts_connection_nolog%& "exemption from connect logging"
.row &%log_file_path%& "override compiled-in value"
.row &%log_selector%& "set/unset optional logging"
.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 &%ignore_fromline_local%& "allow &""From ""& from local SMTP"
.row &%pipelining_advertise_hosts%& "advertise pipelining to these hosts"
.row &%prdr_enable%& "advertise PRDR to all hosts"
+.row &%smtputf8_advertise_hosts%& "advertise SMTPUTF8 to these hosts"
.row &%tls_advertise_hosts%& "advertise TLS to these hosts"
.endtable
not used.
+.new
+.option event_action main string&!! unset
+.cindex events
+This option declares a string to be expanded for Exim's events mechanism.
+For details see &<<CHAPevents>>&.
+.wen
+
+
.option exim_group main string "compile-time configured"
.cindex "gid (group id)" "Exim's own"
.cindex "Exim group"
+.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"
550 failing address in "From" header is: <user@dom.ain
.endd
+
+.new
+.option smtputf8_advertise_hosts main "host list&!!" *
+.cindex "SMTPUTF8" "advertising"
+When Exim is built with support for internationalised mail names,
+the availability therof is advertised in
+response to EHLO only to those client hosts that match this option. See
+chapter &<<CHAPi18n>>& for details of Exim's support for internationalisation.
+.wen
+
+
.option spamd_address main string "see below"
This option is available when Exim is compiled with the content-scanning
extension. It specifies how Exim connects to SpamAssassin's &%spamd%& daemon.
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"
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
resent to other recipients.
+.option event_action transports string&!! unset
+.cindex events
+This option declares a string to be expanded for Exim's events mechanism.
+For details see &<<CHAPevents>>&.
+.wen
+
+
.option group transports string&!! "Exim group"
.cindex "transport" "group; specifying"
This option specifies a gid for running the transport process, overriding any
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
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"
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.
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
will avoid doing so in some situations (e.g. single-recipient mails).
&*Note:*& This control applies only to the current message, not to any others
that are being submitted at the same time using &%-bs%& or &%-bS%&.
+
+.new
+.vitem &*control&~=&~utf8_downconvert*&
+This control enables conversion of UTF-8 in message addresses
+to a-label form.
+For details see &<<SECTi18nMTA>>&.
+.wen
.endlist vlist
session was encrypted, there is an additional X field that records the cipher
suite that was used.
+.cindex log protocol
The protocol is set to &"esmtpsa"& or &"esmtpa"& for messages received from
hosts that have authenticated themselves using the SMTP AUTH command. The first
value is used when the SMTP connection was encrypted (&"secure"&). In this case
.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
&`id `& message id for incoming message
&`P `& on &`<=`& lines: protocol used
&` `& on &`=>`& and &`**`& lines: return path
+&`PRX `& on &'<='& and&`=>`& lines: proxy address
&`QT `& on &`=>`& lines: time spent on queue so far
&` `& on &"Completed"& lines: time spent on queue
&`R `& on &`<=`& lines: reference for local bounce
&` 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
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"
.cindex "TCP/IP" "logging incoming remote port"
DKIM is documented in RFC 4871.
Since version 4.70, DKIM support is compiled into Exim by default. It can be
-disabled by setting DISABLE_DKIM=yes in Local/Makefile.
+disabled by setting DISABLE_DKIM=yes in &_Local/Makefile_&.
Exim's DKIM implementation allows to
.olist
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:
. ////////////////////////////////////////////////////////////////////////////
. ////////////////////////////////////////////////////////////////////////////
+.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 "Internationalisation" "CHAPi18n" &&&
+ "Internationalisation""
+.cindex internationalisation "email address"
+.cindex EAI
+.cindex i18n
+.cindex UTF-8 "mail name handling"
+
+.new
+Exim has support for Internationalised mail names.
+To include this it must be built with SUPPORT_I18N and the libidn library.
+Standards supported are RFCs 2060, 5890, 6530 and 6533.
+
+.section "MTA operations" SECTi18nMTA
+.cindex SMTPUTF8 "ESMTP option"
+The main configuration option &%smtputf8_advertise_hosts%& specifies
+a host list. If this matches the sending host and
+accept_8bitmime is true (the default) then the ESMTP option
+SMTPUTF8 will be advertised.
+
+If the sender specifies the SMTPUTF8 option on a MAIL command
+international handling for the message is enabled and
+the expansion variable &$message_smtputf8$& will have value TRUE.
+
+The option &%allow_utf8_domains%& is set to true for this
+message. All DNS lookups are converted to a-label form
+whatever the setting of &%allow_utf8_domains%&
+when Exim is built with SUPPORT_I18N.
+
+Both localparts and domain are maintained as the original
+UTF-8 form internally; any comparison or regular-expression use will
+require appropriate care. Filenames created, eg. by
+the appendfile transport, will have UTF-8 names.
+
+Helo names sent by the smtp transport will have any UTF-8
+components expanded to a-label form,
+and any certificate name checks will be done using the a-label
+form of the name.
+
+.cindex log protocol
+.cindex SMTPUTF8 logging
+Log lines and Received-by: header lines will acquire a "utf8"
+prefix on the protocol element, eg. utf8esmtp.
+
+The following expansion operator can be used:
+.code
+${utf8_domain_to_alabel:str}
+${utf8_domain_from_alabel:str}
+${utf8_localpart_to_alabel:str}
+${utf8_localpart_from_alabel:str}
+.endd
+
+ACLs may use the following modifier:
+.display
+control = utf8_downconvert
+control = utf8_downconvert/<value>
+.endd
+This sets a flag requiring that addresses are converted to
+a-label form before smtp delivery, for use in a
+Message Submission Agent context.
+If a value is appended it may be:
+.display
+&`1 `& (default) mandatory downconversion
+&`0 `& no downconversion
+&`-1 `& if SMTPUTF8 not supported by destination host
+.endd
+
+If mua_wrapper is set, the utf8_downconvert control
+is initially set to -1.
+
+
+There is no explicit support for VRFY and EXPN.
+Configurations supporting these should inspect
+&$smtp_command_argument$& for an SMTPUTF8 argument.
+
+There is no support for LMTP on Unix sockets.
+Using the "lmtp" protocol option on an smtp transport,
+for LMTP over TCP, should work as expected.
+
+There is no support for DSN unitext handling,
+and no provision for converting logging from or to UTF-8.
+
+
+
+.section "MDA operations" SECTi18nMDA
+To aid in constructing names suitable for IMAP folders
+the following expansion operator can be used:
+.code
+${imapfolder {<string>} {<sep>} {<specials>}}
+.endd
+
+The string is converted from the charset specified by
+the "headers charset" command (in a filter file)
+or &%headers_charset%& main configuration option (otherwise),
+to the
+modified UTF-7 encoding specified by RFC 2060,
+with the following exception: All occurences of <sep>
+(which has to be a single character)
+are replaced with periods ("."), and all periods and slashes that are not
+<sep> and are not in the <specials> string are BASE64 encoded.
+
+The third argument can be omitted, defaulting to an empty string.
+The second argument can be omitted, defaulting to "/".
+
+This is the encoding used by Courier for Maildir names on disk, and followed
+by many other IMAP servers.
+
+Examples:
+.display
+&`${imapfolder {Foo/Bar}} `& yields &`Foo.Bar`&
+&`${imapfolder {Foo/Bar}{.}{/}} `& yields &`Foo&&AC8-Bar`&
+&`${imapfolder {Räksmörgås}} `& yields &`R&&AOQ-ksm&&APY-rg&&AOU-s`&
+.endd
+
+Note that the source charset setting is vital, and also that characters
+must be representable in UTF-16.
+
+.wen
+
+. ////////////////////////////////////////////////////////////////////////////
+. ////////////////////////////////////////////////////////////////////////////
+
+.chapter "Events" "CHAPevents" &&&
+ "Events"
+.cindex events
+
+.new
+The events mechanism in Exim can be used to intercept processing at a number
+of points. It was originally invented to giave a way to do customised logging
+actions (for example, to a database) but can also be used to modify some
+processing actions.
+
+Most installations will never need to use Events.
+The support can be left out of a build by defining DISABLE_EVENT=yes
+in &_Local/Makefile_&.
+
+There are two major classes of events: main and transport.
+The main configuration option &%event_action%& controls reception events;
+a transport option &%event_action%& controls delivery events.
+
+Both options are a string which is expanded when the event fires.
+An example might look like:
+.cindex logging custom
+.code
+event_action = ${if eq {msg:delivery}{$event_name} \
+{${lookup pgsql {SELECT * FROM record_Delivery( \
+ '${quote_pgsql:$sender_address_domain}',\
+ '${quote_pgsql:${lc:$sender_address_local_part}}', \
+ '${quote_pgsql:$domain}', \
+ '${quote_pgsql:${lc:$local_part}}', \
+ '${quote_pgsql:$host_address}', \
+ '${quote_pgsql:${lc:$host}}', \
+ '${quote_pgsql:$message_exim_id}')}} \
+} {}}
+.endd
+
+Events have names which correspond to the point in process at which they fire.
+The name is placed in the variable &$event_name$& and the event action
+expansion must check this, as it will be called for every possible event type.
+
+The current list of events is:
+.display
+&`msg:complete after main `& per message
+&`msg:delivery after transport `& per recipient
+&`msg:rcpt:host:defer after transport `& per recipient per host
+&`msg:rcpt:defer after transport `& per recipient
+&`msg:host:defer after transport `& per attempt
+&`msg:fail:delivery after main `& per recipient
+&`msg:fail:internal after main `& per recipient
+&`tcp:connect before transport `& per connection
+&`tcp:close after transport `& per connection
+&`tls:cert before both `& per certificate in verification chain
+&`smtp:connect after transport `& per connection
+.endd
+New event types may be added in future.
+
+The event name is a colon-separated list, defining the type of
+event in a tree of possibilities. It may be used as a list
+or just matched on as a whole. There will be no spaces in the name.
+
+The second column in the table above describes whether the event fires
+before or after the action is associates with. Those which fire before
+can be used to affect that action (more on this below).
+
+An additional variable, &$event_data$&, is filled with information varying
+with the event type:
+.display
+&`msg:delivery `& smtp confirmation mssage
+&`msg:rcpt:host:defer `& error string
+&`msg:rcpt:defer `& error string
+&`msg:host:defer `& error string
+&`tls:cert `& verification chain depth
+&`smtp:connect `& smtp banner
+.endd
+
+The :defer events populate one extra variable: &$event_defer_errno$&.
+
+For complex operations an ACL expansion can be used in &%event_action%&
+however due to the multiple contextx that Exim operates in during
+the course of its processing:
+.ilist
+variables set in transport events will not be visible outside that
+transport call
+.next
+acl_m variables in a server context are lost on a new connection,
+and after smtp helo/ehlo/mail/starttls/rset commands
+.endlist
+Using an ACL expansion with the logwrite modifier can be
+a useful way of writing to the main log.
+
+The expansion of the event_action option should normally
+return an empty string. Should it return anything else the
+following will be forced:
+.display
+&`msg:delivery `& (ignored)
+&`msg:host:defer `& (ignored)
+&`msg:fail:delivery`& (ignored)
+&`tcp:connect `& do not connect
+&`tcp:close `& (ignored)
+&`tls:cert `& refuse verification
+&`smtp:connect `& close connection
+.endd
+No other use is made of the result string.
+
+For a tcp:connect event, if the connection is being made to a proxy
+then the address and port variables will be that of the proxy and not
+the target system.
+
+For tls:cert events, if GnuTLS is in use this will trigger only per
+chain element received on the connection.
+For OpenSSL it will trigger for every chain element including those
+loaded locally.
+.wen
+
+. ////////////////////////////////////////////////////////////////////////////
+. ////////////////////////////////////////////////////////////////////////////
+
.chapter "Adding new drivers or lookup types" "CHID13" &&&
"Adding drivers or lookups"
.cindex "adding drivers"
git://git.exim.org / exim.git / blobdiff