X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/6e48a63849cd3f1dfb3555fe57094954b3f7f092..212c50c3b5dcdf00442933496a44b1d1db6908b5:/doc/doc-docbook/spec.xfpt diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index 1f0f473d8..15d909be0 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -45,7 +45,7 @@ . Update the Copyright year (only) when changing content. . ///////////////////////////////////////////////////////////////////////////// -.set previousversion "4.95" +.set previousversion "4.96" .include ./local_params .set ACL "access control lists (ACLs)" @@ -54,7 +54,7 @@ .set drivernamemax "64" .macro copyyear -2021 +2022 .endmacro . ///////////////////////////////////////////////////////////////////////////// @@ -97,6 +97,34 @@ .itable none 0 0 2 $1 left $2 left .endmacro + +. --- A macro for a plain variable, including the .vitem and .vindex +.macro var +.vitem $1 +.vindex $1 +.endmacro + +. --- A macro for a "tainted" marker, done as a one-element table +.macro tmark +.itable none 0 0 1 10pt left +.row &'Tainted'& +.endtable +.endmacro + +. --- A macro for a tainted variable, adding a taint-marker +.macro tvar +.var $1 +.tmark +.endmacro + +. --- A macro for a cmdline option, including a .oindex +. --- 1st arg is the option name, undecorated (we do that here). +. --- 2nd arg, optional, text (decorated as needed) to be appended to the name +.macro cmdopt +.vitem &%$1%&$=2+&~$2+ +.oindex &%$1%& +.endmacro + . --- A macro that generates .row, but puts &I; at the start of the first . --- argument, thus indenting it. Assume a minimum of two arguments, and . --- allow up to four arguments, which is as many as we'll ever need. @@ -119,6 +147,8 @@ . --- style of entry, use .scindex for the start and .ecindex for the end. The . --- first argument of .scindex and the only argument of .ecindex must be the . --- ID that ties them together. +. --- The index entry points to the most-recent chapter head, section or subsection +. --- head, or list-item. .macro cindex && @@ -151,6 +181,9 @@ && .endmacro +. --- The index entry points to the most-recent chapter head, section or subsection +. --- head, or varlist item. + .macro vindex && &&$1&& @@ -199,142 +232,63 @@ . ///////////////////////////////////////////////////////////////////////////// -. This chunk of literal XML implements index entries of the form "x, see y" and -. "x, see also y". However, the DocBook DTD doesn't allow entries +. These implement index entries of the form "x, see y" and "x, see also y". +. However, the DocBook DTD doesn't allow entries . at the top level, so we have to put the .chapter directive first. - -. These do not turn up in the HTML output, unfortunately. The PDF does get them. . ///////////////////////////////////////////////////////////////////////////// .chapter "Introduction" "CHID1" -.literal xml - - $1, $2, etc. - numerical variables - - - address - rewriting - rewriting - - - Bounce Address Tag Validation - BATV - - - Client SMTP Authorization - CSA - - - CR character - carriage return - - - CRL - certificate revocation list - - - delivery - failure report - bounce message - - - dialup - intermittently connected hosts - - - exiscan - content scanning - - - failover - fallback - - - fallover - fallback - - - filter - Sieve - Sieve filter - - - ident - RFC 1413 - - - LF character - linefeed - - - maximum - limit - - - monitor - Exim monitor - - - no_xxx - entry for xxx - - - NUL - binary zero - - - passwd file - /etc/passwd - - - process id - pid - - - RBL - DNS list - - - redirection - address redirection - - - return path - envelope sender - - - scanning - content scanning - - - SSL - TLS - - - string - expansion - expansion - - - top bit - 8-bit characters - - - variables - expansion, variables - - - zero, binary - binary zero - - - headers - header lines +.macro seeother +.literal xml + + $3 +.arg 5 + $5 +.endarg + <$1>$4 - .literal off +.endmacro + +. NB: for the 4-arg variant the ordering is awkward +.macro see +.seeother see "$1" "$2" "$3" "$4" +.endmacro +.macro seealso +.seeother seealso "$1" "$2" "$3" "$4" +.endmacro + +.see variable "$1, $2, etc." "numerical variables" +.see concept address rewriting rewriting +.see concept "Bounce Address Tag Validation" BATV +.see concept "Client SMTP Authorization" CSA +.see concept "CR character" "carriage return" +.see concept CRL "certificate revocation list" +.seealso concept de-tainting "tainted data" +.see concept delivery "bounce message" "failure report" +.see concept dialup "intermittently connected hosts" +.see concept exiscan "content scanning" +.see concept fallover fallback +.see concept filter "Sieve filter" Sieve +.see concept headers "header lines" +.see concept ident "RFC 1413" +.see concept "LF character" "linefeed" +.seealso concept maximum limit +.see concept monitor "Exim monitor" +.see concept "no_xxx" "entry for xxx" +.see concept NUL "binary zero" +.see concept "passwd file" "/etc/passwd" +.see concept "process id" pid +.see concept RBL "DNS list" +.see concept redirection "address redirection" +.see concept "return path" "envelope sender" +.see concept scanning "content scanning" +.see concept SSL TLS +.see concept string expansion expansion +.see concept "top bit" "8-bit characters" +.see concept variables "expansion, variables" +.see concept "zero, binary" "binary zero" . ///////////////////////////////////////////////////////////////////////////// @@ -1378,7 +1332,7 @@ The preconditions that are tested for each router are listed below, in the order in which they are tested. The individual configuration options are described in more detail in chapter &<>&. -.ilist +.olist .cindex affix "router precondition" The &%local_part_prefix%& and &%local_part_suffix%& options can specify that the local parts handled by the router may or must have certain prefixes and/or @@ -1414,6 +1368,7 @@ check an address given in the SMTP EXPN command (see the &%expn%& option). If the &%domains%& option is set, the domain of the address must be in the set of domains that it defines. .cindex "tainted data" "de-tainting" +.cindex "de-tainting" "using router domains option" A match verifies the variable &$domain$& (which carries tainted data) and assigns an untainted value to the &$domain_data$& variable. Such an untainted value is often needed in the transport. @@ -1504,7 +1459,7 @@ example, &_.procmailrc_&). .cindex "delivery" "in detail" When a message is to be delivered, the sequence of events is as follows: -.ilist +.olist If a system-wide filter file is specified, the message is passed to it. The filter may add recipients to the message, replace the recipients, discard the message, cause a new message to be generated, or cause the message delivery to @@ -1615,7 +1570,7 @@ as permanent. -.section "Temporary delivery failure" "SECID20" +.subsection "Temporary delivery failure" SECID20 .cindex "delivery" "temporary failure" There are many reasons why a message may not be immediately deliverable to a particular address. Failure to connect to a remote machine (because it, or the @@ -1639,7 +1594,7 @@ one connection. -.section "Permanent delivery failure" "SECID21" +.subsection "Permanent delivery failure" SECID21 .cindex "delivery" "permanent failure" .cindex "bounce message" "when generated" When a message cannot be delivered to some or all of its intended recipients, a @@ -1667,7 +1622,7 @@ of the list. -.section "Failures to deliver bounce messages" "SECID22" +.subsection "Failures to deliver bounce messages" SECID22 .cindex "bounce message" "failure to deliver" If a bounce message (either locally generated or received from a remote host) itself suffers a permanent delivery failure, the message is left in the queue, @@ -1804,11 +1759,9 @@ the traditional &'ndbm'& interface. To complicate things further, there are several very different versions of the Berkeley DB package. Version 1.85 was stable for a very long time, releases 2.&'x'& and 3.&'x'& were current for a while, -.new but the latest versions when Exim last revamped support were numbered 5.&'x'&. Maintenance of some of the earlier releases has ceased, and Exim no longer supports versions before 3.&'x'&. -.wen All versions of Berkeley DB could be obtained from &url(http://www.sleepycat.com/), which is now a redirect to their new owner's page with far newer versions listed. @@ -1833,9 +1786,7 @@ USE_DB=yes .endd Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An error is diagnosed if you set more than one of these. -.new You can set USE_NDBM if needed to override an operating system default. -.wen At the lowest level, the build-time configuration sets none of these options, thereby assuming an interface of type (1). However, some operating system @@ -1852,9 +1803,7 @@ DBMLIB = -ldb DBMLIB = -ltdb DBMLIB = -lgdbm -lgdbm_compat .endd -.new The last of those was for a Linux having GDBM provide emulated NDBM facilities. -.wen Settings like that will work if the DBM library is installed in the standard place. Sometimes it is not, and the library's header file may also not be in the default path. You may need to set INCLUDE to specify where the header @@ -2786,21 +2735,18 @@ outputs a brief message about itself and exits. .vlist -.vitem &%--%& -.oindex "--" +.cmdopt "--" "--" .cindex "options" "command line; terminating" This is a pseudo-option whose only purpose is to terminate the options and therefore to cause subsequent command line items to be treated as arguments rather than options, even if they begin with hyphens. -.vitem &%--help%& -.oindex "&%--help%&" +.cmdopt --help This option causes Exim to output a few sentences stating what it is. The same output is generated if the Exim binary is called with no options and no arguments. -.vitem &%--version%& -.oindex "&%--version%&" +.cmdopt --version This option is an alias for &%-bV%& and causes version information to be displayed. @@ -2811,15 +2757,14 @@ displayed. These options are used by Sendmail for selecting configuration files and are ignored by Exim. -.vitem &%-B%&<&'type'&> +.cmdopt -B <&'type'&> .oindex "&%-B%&" .cindex "8-bit characters" .cindex "Sendmail compatibility" "8-bit characters" This is a Sendmail option for selecting 7 or 8 bit processing. Exim is 8-bit clean; it ignores this option. -.vitem &%-bd%& -.oindex "&%-bd%&" +.cmdopt -bd .cindex "daemon" .cindex "SMTP" "listener" .cindex "queue runner" @@ -2865,13 +2810,11 @@ of Exim is installed. It is not necessary to do this when other files that are referenced from the configuration (for example, alias files) are changed, because these are reread each time they are used. -.vitem &%-bdf%& -.oindex "&%-bdf%&" +.cmdopt -bdf This option has the same effect as &%-bd%& except that it never disconnects from the controlling terminal, even when no debugging is specified. -.vitem &%-be%& -.oindex "&%-be%&" +.cmdopt -be .cindex "testing" "string expansion" .cindex "expansion" "testing" Run Exim in expansion testing mode. Exim discards its root privilege, to @@ -2903,8 +2846,13 @@ defined and macros will be expanded. Because macros in the config file are often used for secrets, those are only available to admin users. -.vitem &%-bem%&&~<&'filename'&> -.oindex "&%-bem%&" +.new +The word &"set"& at the start of a line, followed by a single space, +is recognised specially as defining a value for a variable. +The syntax is otherwise the same as the ACL modifier &"set ="&. +.wen + +.cmdopt -bem <&'filename'&> .cindex "testing" "string expansion" .cindex "expansion" "testing" This option operates like &%-be%& except that it must be followed by the name @@ -2921,16 +2869,14 @@ recipients are read from the headers in the normal way, and are shown in the line, because further arguments are taken as strings to expand (just like &%-be%&). -.vitem &%-bF%&&~<&'filename'&> -.oindex "&%-bF%&" +.cmdopt -bF <&'filename'&> .cindex "system filter" "testing" .cindex "testing" "system filter" This option is the same as &%-bf%& except that it assumes that the filter being tested is a system filter. The additional commands that are available only in system filters are recognized. -.vitem &%-bf%&&~<&'filename'&> -.oindex "&%-bf%&" +.cmdopt -bf <&'filename'&> .cindex "filter" "testing" .cindex "testing" "filter file" .cindex "forward file" "testing" @@ -2976,37 +2922,32 @@ that would normally be taken from the envelope recipient address of the message can be set by means of additional command line options (see the next four options). -.vitem &%-bfd%&&~<&'domain'&> -.oindex "&%-bfd%&" +.cmdopt -bfd <&'domain'&> .vindex "&$qualify_domain$&" This sets the domain of the recipient address when a filter file is being tested by means of the &%-bf%& option. The default is the value of &$qualify_domain$&. -.vitem &%-bfl%&&~<&'local&~part'&> -.oindex "&%-bfl%&" +.cmdopt -bfl <&'local&~part'&> This sets the local part of the recipient address when a filter file is being tested by means of the &%-bf%& option. The default is the username of the process that calls Exim. A local part should be specified with any prefix or suffix stripped, because that is how it appears to the filter when a message is actually being delivered. -.vitem &%-bfp%&&~<&'prefix'&> -.oindex "&%-bfp%&" +.cmdopt -bfp <&'prefix'&> .cindex affix "filter testing" This sets the prefix of the local part of the recipient address when a filter file is being tested by means of the &%-bf%& option. The default is an empty prefix. -.vitem &%-bfs%&&~<&'suffix'&> -.oindex "&%-bfs%&" +.cmdopt -bfs <&'suffix'&> .cindex affix "filter testing" This sets the suffix of the local part of the recipient address when a filter file is being tested by means of the &%-bf%& option. The default is an empty suffix. -.vitem &%-bh%&&~<&'IP&~address'&> -.oindex "&%-bh%&" +.cmdopt -bh <&'IP&~address'&> .cindex "testing" "incoming SMTP" .cindex "SMTP" "testing incoming" .cindex "testing" "relay control" @@ -3058,14 +2999,12 @@ plain text, cannot easily be tested with &%-bh%&. Instead, you should use a specialized SMTP test program such as &url(https://www.jetmore.org/john/code/swaks/,swaks). -.vitem &%-bhc%&&~<&'IP&~address'&> -.oindex "&%-bhc%&" +.cmdopt -bhc <&'IP&~address'&> This option operates in the same way as &%-bh%&, except that address verification callouts are performed if required. This includes consulting and updating the callout cache database. -.vitem &%-bi%& -.oindex "&%-bi%&" +.cmdopt -bi .cindex "alias file" "building" .cindex "building alias file" .cindex "Sendmail compatibility" "&%-bi%& option" @@ -3084,8 +3023,7 @@ if this is required. If the &%bi_command%& option is not set, calling Exim with &%-bi%& is a no-op. . // Keep :help first, then the rest in alphabetical order -.vitem &%-bI:help%& -.oindex "&%-bI:help%&" +.cmdopt -bI:help .cindex "querying exim information" We shall provide various options starting &`-bI:`& for querying Exim for information. The output of many of these will be intended for machine @@ -3093,14 +3031,12 @@ consumption. This one is not. The &%-bI:help%& option asks Exim for a synopsis of supported options beginning &`-bI:`&. Use of any of these options shall cause Exim to exit after producing the requested output. -.vitem &%-bI:dscp%& -.oindex "&%-bI:dscp%&" +.cmdopt -bI:dscp .cindex "DSCP" "values" This option causes Exim to emit an alphabetically sorted list of all recognised DSCP names. -.vitem &%-bI:sieve%& -.oindex "&%-bI:sieve%&" +.cmdopt -bI:sieve .cindex "Sieve filter" "capabilities" This option causes Exim to emit an alphabetically sorted list of all supported Sieve protocol extensions on stdout, one per line. This is anticipated to be @@ -3109,8 +3045,7 @@ useful for ManageSieve (RFC 5804) implementations, in providing that protocol's compile-time build options, which this option will adapt to, this is the only way to guarantee a correct response. -.vitem &%-bm%& -.oindex "&%-bm%&" +.cmdopt -bm .cindex "local message reception" This option runs an Exim receiving process that accepts an incoming, locally-generated message on the standard input. The recipients are given as the @@ -3155,8 +3090,7 @@ The specified sender is treated as if it were given as the argument to the preference to the address taken from the message. The caller of Exim must be a trusted user for the sender of a message to be set in this way. -.vitem &%-bmalware%&&~<&'filename'&> -.oindex "&%-bmalware%&" +.cmdopt -bmalware <&'filename'&> .cindex "testing", "malware" .cindex "malware scan test" This debugging option causes Exim to scan the given file or directory @@ -3176,8 +3110,7 @@ The &%-bmalware%& option will not be extended to be more generally useful, there are better tools for file-scanning. This option exists to help administrators verify their Exim and AV scanner configuration. -.vitem &%-bnq%& -.oindex "&%-bnq%&" +.cmdopt -bnq .cindex "address qualification, suppressing" By default, Exim automatically qualifies unqualified addresses (those without domains) that appear in messages that are submitted locally (that @@ -3198,8 +3131,7 @@ addresses in the envelope provoke errors (causing message rejection) and unqualified addresses in header lines are left alone. -.vitem &%-bP%& -.oindex "&%-bP%&" +.cmdopt -bP .cindex "configuration options" "extracting" .cindex "options" "configuration &-- extracting" If this option is given with no arguments, it causes the values of all Exim's @@ -3275,8 +3207,7 @@ The output format is one item per line. For the "-bP macro " form, if no such macro is found the exit status will be nonzero. -.vitem &%-bp%& -.oindex "&%-bp%&" +.cmdopt -bp .cindex "queue" "listing messages in" .cindex "listing" "messages in the queue" This option requests a listing of the contents of the mail queue on the @@ -3313,48 +3244,41 @@ displayed with a D only when deliveries for all of its child addresses are complete. -.vitem &%-bpa%& -.oindex "&%-bpa%&" +.cmdopt -bpa This option operates like &%-bp%&, but in addition it shows delivered addresses that were generated from the original top level address(es) in each message by alias or forwarding operations. These addresses are flagged with &"+D"& instead of just &"D"&. -.vitem &%-bpc%& -.oindex "&%-bpc%&" +.cmdopt -bpc .cindex "queue" "count of messages on" This option counts the number of messages in the queue, and writes the total to the standard output. It is restricted to admin users, unless &%queue_list_requires_admin%& is set false. -.vitem &%-bpr%& -.oindex "&%-bpr%&" +.cmdopt -bpr This option operates like &%-bp%&, but the output is not sorted into chronological order of message arrival. This can speed it up when there are lots of messages in the queue, and is particularly useful if the output is going to be post-processed in a way that doesn't need the sorting. -.vitem &%-bpra%& -.oindex "&%-bpra%&" +.cmdopt -bpra This option is a combination of &%-bpr%& and &%-bpa%&. -.vitem &%-bpru%& -.oindex "&%-bpru%&" +.cmdopt -bpru This option is a combination of &%-bpr%& and &%-bpu%&. -.vitem &%-bpu%& -.oindex "&%-bpu%&" +.cmdopt -bpu This option operates like &%-bp%& but shows only undelivered top-level addresses for each message displayed. Addresses generated by aliasing or forwarding are not shown, unless the message was deferred after processing by a router with the &%one_time%& option set. -.vitem &%-brt%& -.oindex "&%-brt%&" +.cmdopt -brt .cindex "testing" "retry configuration" .cindex "retry" "configuration testing" This option is for testing retry rules, and it must be followed by up to three @@ -3378,8 +3302,7 @@ exim -brt haydn.comp.mus.example quota_3d Retry rule: *@haydn.comp.mus.example quota_3d F,1h,15m .endd -.vitem &%-brw%& -.oindex "&%-brw%&" +.cmdopt -brw .cindex "testing" "rewriting" .cindex "rewriting" "testing" This option is for testing address rewriting rules, and it must be followed by @@ -3388,8 +3311,7 @@ complete address with a fully qualified domain. Exim outputs how this address would be rewritten for each possible place it might appear. See chapter &<>& for further details. -.vitem &%-bS%& -.oindex "&%-bS%&" +.cmdopt -bS .cindex "SMTP" "batched incoming" .cindex "batched SMTP input" This option is used for batched SMTP input, which is an alternative interface @@ -3422,8 +3344,7 @@ was detected; otherwise it is 2. More details of input using batched SMTP are given in section &<>&. -.vitem &%-bs%& -.oindex "&%-bs%&" +.cmdopt -bs .cindex "SMTP" "local input" .cindex "local SMTP input" This option causes Exim to accept one or more messages by reading SMTP commands @@ -3451,8 +3372,7 @@ above concerning senders and qualification do not apply. In this situation, Exim behaves in exactly the same way as it does when receiving a message via the listening daemon. -.vitem &%-bt%& -.oindex "&%-bt%&" +.cmdopt -bt .cindex "testing" "addresses" .cindex "address" "testing" This option runs Exim in address testing mode, in which each argument is taken @@ -3497,8 +3417,7 @@ whose behaviour depends on the contents of an incoming message, you cannot test those conditions using &%-bt%&. The &%-N%& option provides a possible way of doing such tests. -.vitem &%-bV%& -.oindex "&%-bV%&" +.cmdopt -bV .cindex "version number of Exim" This option causes Exim to write the current version number, compilation number, and compilation date of the &'exim'& binary to the standard output. @@ -3514,8 +3433,7 @@ alone to discover (for example) all the typos in the configuration; some realistic testing is needed. The &%-bh%& and &%-N%& options provide more dynamic testing facilities. -.vitem &%-bv%& -.oindex "&%-bv%&" +.cmdopt -bv .cindex "verifying address" "using &%-bv%&" .cindex "address" "verification" This option runs Exim in address verification mode, in which each argument is @@ -3565,14 +3483,12 @@ address of a message, you should use the &%-f%& option to set an appropriate sender when running &%-bv%& tests. Without it, the sender is assumed to be the calling user at the default qualifying domain. -.vitem &%-bvs%& -.oindex "&%-bvs%&" +.cmdopt -bvs This option acts like &%-bv%&, but verifies the address as a sender rather than a recipient address. This affects any rewriting and qualification that might happen. -.vitem &%-bw%& -.oindex "&%-bw%&" +.cmdopt -bw .cindex "daemon" .cindex "inetd" .cindex "inetd" "wait mode" @@ -3588,8 +3504,7 @@ each port only when the first connection is received. If the option is given as &%-bw%&<&'time'&> then the time is a timeout, after which the daemon will exit, which should cause inetd to listen once more. -.vitem &%-C%&&~<&'filelist'&> -.oindex "&%-C%&" +.cmdopt -C <&'filelist'&> .cindex "configuration file" "alternate" .cindex "CONFIGURE_FILE" .cindex "alternate configuration file" @@ -3692,41 +3607,41 @@ of debugging data, respectively. For example, &%-d+filter%& adds filter debugging, whereas &%-d-all+filter%& selects only filter debugging. Note that no spaces are allowed in the debug setting. The available debugging categories are: -.display -&`acl `& ACL interpretation -&`auth `& authenticators -&`deliver `& general delivery logic -&`dns `& DNS lookups (see also resolver) -&`dnsbl `& DNS black list (aka RBL) code -&`exec `& arguments for &[execv()]& calls -&`expand `& detailed debugging for string expansions -&`filter `& filter handling -&`hints_lookup `& hints data lookups -&`host_lookup `& all types of name-to-IP address handling -&`ident `& ident lookup -&`interface `& lists of local interfaces -&`lists `& matching things in lists -&`load `& system load checks -&`local_scan `& can be used by &[local_scan()]& (see chapter &&& - &<>&) -&`lookup `& general lookup code and all lookups -&`memory `& memory handling -&`noutf8 `& modifier: avoid UTF-8 line-drawing -&`pid `& modifier: add pid to debug output lines -&`process_info `& setting info for the process log -&`queue_run `& queue runs -&`receive `& general message reception logic -&`resolver `& turn on the DNS resolver's debugging output -&`retry `& retry handling -&`rewrite `& address rewriting -&`route `& address routing -&`timestamp `& modifier: add timestamp to debug output lines -&`tls `& TLS logic -&`transport `& transports -&`uid `& changes of uid/gid and looking up uid/gid -&`verify `& address verification logic -&`all `& almost all of the above (see below), and also &%-v%& -.endd +.itable none 0 0 2 20* left 80* left +.irow acl "ACL interpretation" +.irow auth "authenticators" +.irow deliver "general delivery logic" +.irow dns "DNS lookups (see also resolver)" +.irow dnsbl "DNS black list (aka RBL) code" +.irow exec "arguments for &[execv()]& calls" +.irow expand "detailed debugging for string expansions" +.irow filter "filter handling" +.irow hints_lookup "hints data lookups" +.irow host_lookup "all types of name-to-IP address handling" +.irow ident "ident lookup" +.irow interface "lists of local interfaces" +.irow lists "matching things in lists" +.irow load "system load checks" +.irow local_scan "can be used by &[local_scan()]& (see chapter &&& + &<>&)" +.irow lookup "general lookup code and all lookups" +.irow memory "memory handling" +.irow noutf8 "modifier: avoid UTF-8 line-drawing" +.irow pid "modifier: add pid to debug output lines" +.irow process_info "setting info for the process log" +.irow queue_run "queue runs" +.irow receive "general message reception logic" +.irow resolver "turn on the DNS resolver's debugging output" +.irow retry "retry handling" +.irow rewrite "address rewriting"" +.irow route "address routing" +.irow timestamp "modifier: add timestamp to debug output lines" +.irow tls "TLS logic" +.irow transport "transports" +.irow uid "changes of uid/gid and looking up uid/gid" +.irow verify "address verification logic" +.irow all "almost all of the above (see below), and also &%-v%&" +.endtable The &`all`& option excludes &`memory`& when used as &`+all`&, but includes it for &`-all`&. The reason for this is that &`+all`& is something that people tend to use when generating debug output for Exim maintainers. If &`+memory`& @@ -3769,14 +3684,12 @@ starts a daemon process. In that case, debugging is turned off for the subprocesses that the daemon creates. Thus, it is useful for monitoring the behaviour of the daemon without creating as much output as full debugging does. -.vitem &%-dropcr%& -.oindex "&%-dropcr%&" +.cmdopt -dropcr 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 &<>&. -.vitem &%-E%& -.oindex "&%-E%&" +.cmdopt -E .cindex "bounce message" "generating" This option specifies that an incoming message is a locally-generated delivery failure report. It is used internally by Exim when handling delivery failures @@ -3793,8 +3706,7 @@ called by various programs without the leading &%o%& in the option. For example, the &%vacation%& program uses &%-eq%&. Exim treats all options of the form &%-e%&&'x'& as synonymous with the corresponding &%-oe%&&'x'& options. -.vitem &%-F%&&~<&'string'&> -.oindex "&%-F%&" +.cmdopt -F <&'string'&> .cindex "sender" "name" .cindex "name" "of sender" This option sets the sender's full name for use when a locally-generated @@ -3803,8 +3715,7 @@ entry from the password data is used. As users are generally permitted to alter their &'gecos'& entries, no security considerations are involved. White space between &%-F%& and the <&'string'&> is optional. -.vitem &%-f%&&~<&'address'&> -.oindex "&%-f%&" +.cmdopt -f <&'address'&> .cindex "sender" "address" .cindex "address" "sender" .cindex "trusted users" @@ -3848,8 +3759,7 @@ locally-generated message can also be set (when permitted) by an initial &"From&~"& line in the message &-- see the description of &%-bm%& above &-- but if &%-f%& is also present, it overrides &"From&~"&. -.vitem &%-G%& -.oindex "&%-G%&" +.cmdopt -G .cindex "submission fixups, suppressing (command-line)" This option is equivalent to an ACL applying: .code @@ -3862,15 +3772,13 @@ in future. As this affects audit information, the caller must be a trusted user to use this option. -.vitem &%-h%&&~<&'number'&> -.oindex "&%-h%&" +.cmdopt -h <&'number'&> .cindex "Sendmail compatibility" "&%-h%& option ignored" This option is accepted for compatibility with Sendmail, but has no effect. (In Sendmail it overrides the &"hop count"& obtained by counting &'Received:'& headers.) -.vitem &%-i%& -.oindex "&%-i%&" +.cmdopt -i .cindex "Solaris" "&'mail'& command" .cindex "dot" "in incoming non-SMTP message" This option, which has the same effect as &%-oi%&, specifies that a dot on a @@ -3880,8 +3788,7 @@ Solaris 2.4 (SunOS 5.4) Sendmail has a similar &%-i%& processing option p. 1M-529), and therefore a &%-oi%& command line option, which both are used by its &'mailx'& command. -.vitem &%-L%&&~<&'tag'&> -.oindex "&%-L%&" +.cmdopt -L <&'tag'&> .cindex "syslog" "process name; set with flag" This option is equivalent to setting &%syslog_processname%& in the config file and setting &%log_file_path%& to &`syslog`&. @@ -3891,8 +3798,7 @@ effect, so early configuration file errors will not honour this flag. The tag should not be longer than 32 characters. -.vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~... -.oindex "&%-M%&" +.cmdopt -M <&'message&~id'&>&~<&'message&~id'&>&~... .cindex "forcing delivery" .cindex "delivery" "forcing attempt" .cindex "frozen messages" "forcing delivery" @@ -3914,8 +3820,7 @@ not terminate until all the delivery attempts have finished. No output is produced unless there is a serious error. If you want to see what is happening, use the &%-v%& option as well, or inspect Exim's main log. -.vitem &%-Mar%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~... -.oindex "&%-Mar%&" +.cmdopt -Mar <&'message&~id'&>&~<&'address'&>&~<&'address'&>&~... .cindex "message" "adding recipients" .cindex "recipient" "adding" This option requests Exim to add the addresses to the list of recipients of the @@ -3938,59 +3843,50 @@ an existing SMTP connection, which is passed as the standard input. Details are given in chapter &<>&. This must be the final option, and the caller must be root or the Exim user in order to use it. -.vitem &%-MCA%& -.oindex "&%-MCA%&" +.cmdopt -MCA 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. -.vitem &%-MCD%& -.oindex "&%-MCD%&" +.cmdopt -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 &%-MCd%& -.oindex "&%-MCd%&" +.cmdopt -MCd This option is not intended for use by external callers. It is used internally by Exim in conjunction with the &%-d%& option to pass on an information string on the purpose of the process. -.vitem &%-MCG%&&~<&'queue&~name'&> -.oindex "&%-MCG%&" +.cmdopt -MCG <&'queue&~name'&> 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 an alternate queue is used, named by the following argument. -.vitem &%-MCK%& -.oindex "&%-MCK%&" +.cmdopt -MCK 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 a remote host supports the ESMTP &_CHUNKING_& extension. -.vitem &%-MCL%& -.oindex "&%-MCL%&" +.cmdopt -MCL 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 server to which Exim is connected advertised limits on numbers of mails, recipients or recipient domains. The limits are given by the following three arguments. -.vitem &%-MCP%& -.oindex "&%-MCP%&" +.cmdopt -MCP 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 server to which Exim is connected supports pipelining. -.vitem &%-MCp%& -.oindex "&%-MCp%&" +.cmdopt -MCp 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 t a remote server is via a SOCKS proxy, using addresses and ports given by the following four arguments. -.vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&> -.oindex "&%-MCQ%&" +.cmdopt -MCQ <&'process&~id'&>&~<&'pipe&~fd'&> This option is not intended for use by external callers. It is used internally by Exim in conjunction with the &%-MC%& option when the original delivery was started by a queue runner. It passes on the process id of the queue runner, @@ -3998,20 +3894,17 @@ together with the file descriptor number of an open pipe. Closure of the pipe signals the final completion of the sequence of processes that are passing messages through the same SMTP connection. -.vitem &%-MCq%&&~<&'recipient&~address'&>&~<&'size'&> -.oindex "&%-MCq%&" +.cmdopt -MCq <&'recipient&~address'&>&~<&'size'&> This option is not intended for use by external callers. It is used internally by Exim to implement quota checking for local users. -.vitem &%-MCS%& -.oindex "&%-MCS%&" +.cmdopt -MCS This option is not intended for use by external callers. It is used internally by Exim in conjunction with the &%-MC%& option, and passes on the fact that the ESMTP SIZE option should be used on messages delivered down the existing connection. -.vitem &%-MCT%& -.oindex "&%-MCT%&" +.cmdopt -MCT This option is not intended for use by external callers. It is used internally by Exim in conjunction with the &%-MC%& option, and passes on the fact that the host to which Exim is connected supports TLS encryption. @@ -4026,15 +3919,13 @@ a TLS Server Name Indication was sent as part of the channel establishment. The argument gives the SNI string. The "r" variant indicates a DANE-verified connection. -.vitem &%-MCt%&&~<&'IP&~address'&>&~<&'port'&>&~<&'cipher'&> -.oindex "&%-MCt%&" +.cmdopt -MCt <&'IP&~address'&>&~<&'port'&>&~<&'cipher'&> This option is not intended for use by external callers. It is used internally by Exim in conjunction with the &%-MC%& option, and passes on the fact that the connection is being proxied by a parent process for handling TLS encryption. The arguments give the local address and port being proxied, and the TLS cipher. -.vitem &%-Mc%&&~<&'message&~id'&>&~<&'message&~id'&>&~... -.oindex "&%-Mc%&" +.cmdopt -Mc <&'message&~id'&>&~<&'message&~id'&>&~... .cindex "hints database" "not overridden by &%-Mc%&" .cindex "delivery" "manually started &-- not forced" This option requests Exim to run a delivery attempt on each message, in turn, @@ -4049,8 +3940,7 @@ If you want to run a specific delivery as if in a queue run, you should use &%-q%& with a message id argument. A distinction between queue run deliveries and other deliveries is made in one or two places. -.vitem &%-Mes%&&~<&'message&~id'&>&~<&'address'&> -.oindex "&%-Mes%&" +.cmdopt -Mes <&'message&~id'&>&~<&'address'&> .cindex "message" "changing sender" .cindex "sender" "changing" This option requests Exim to change the sender address in the message to the @@ -4060,8 +3950,7 @@ be a message id, and the second one an email address. However, if the message is active (in the middle of a delivery attempt), its status is not altered. This option can be used only by an admin user. -.vitem &%-Mf%&&~<&'message&~id'&>&~<&'message&~id'&>&~... -.oindex "&%-Mf%&" +.cmdopt -Mf <&'message&~id'&>&~<&'message&~id'&>&~... .cindex "freezing messages" .cindex "message" "manually freezing" This option requests Exim to mark each listed message as &"frozen"&. This @@ -4071,8 +3960,7 @@ However, if any of the messages are active (in the middle of a delivery attempt), their status is not altered. This option can be used only by an admin user. -.vitem &%-Mg%&&~<&'message&~id'&>&~<&'message&~id'&>&~... -.oindex "&%-Mg%&" +.cmdopt -Mg <&'message&~id'&>&~<&'message&~id'&>&~... .cindex "giving up on messages" .cindex "message" "abandoning delivery attempts" .cindex "delivery" "abandoning further attempts" @@ -4083,8 +3971,7 @@ is sent to the sender, containing the text &"cancelled by administrator"&. Bounce messages are just discarded. This option can be used only by an admin user. -.vitem &%-MG%&&~<&'queue&~name'&>&~<&'message&~id'&>&~<&'message&~id'&>&~... -.oindex "&%-MG%&" +.cmdopt -MG <&'queue&~name'&>&~<&'message&~id'&>&~<&'message&~id'&>&~... .cindex queue named .cindex "named queues" "moving messages" .cindex "queue" "moving messages" @@ -4095,16 +3982,14 @@ string to define the default queue. If the messages are not currently located in the default queue, a &%-qG%& option will be required to define the source queue. -.vitem &%-Mmad%&&~<&'message&~id'&>&~<&'message&~id'&>&~... -.oindex "&%-Mmad%&" +.cmdopt -Mmad <&'message&~id'&>&~<&'message&~id'&>&~... .cindex "delivery" "cancelling all" This option requests Exim to mark all the recipient addresses in the messages as already delivered (&"mad"& for &"mark all delivered"&). However, if any message is active (in the middle of a delivery attempt), its status is not altered. This option can be used only by an admin user. -.vitem &%-Mmd%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~... -.oindex "&%-Mmd%&" +.cmdopt -Mmd <&'message&~id'&>&~<&'address'&>&~<&'address'&>&~... .cindex "delivery" "cancelling by address" .cindex "recipient" "removing" .cindex "removing recipients" @@ -4115,8 +4000,7 @@ addresses in the message in a case-sensitive manner. If the message is active (in the middle of a delivery attempt), its status is not altered. This option can be used only by an admin user. -.vitem &%-Mrm%&&~<&'message&~id'&>&~<&'message&~id'&>&~... -.oindex "&%-Mrm%&" +.cmdopt -Mrm <&'message&~id'&>&~<&'message&~id'&>&~... .cindex "removing messages" .cindex "abandoning mail" .cindex "message" "manually discarding" @@ -4135,8 +4019,7 @@ placed in the queue. . a bounce message. . .wen -.vitem &%-Mset%&&~<&'message&~id'&> -.oindex "&%-Mset%&" +.cmdopt -Mset <&'message&~id'&> .cindex "testing" "string expansion" .cindex "expansion" "testing" This option is useful only in conjunction with &%-be%& (that is, when testing @@ -4147,8 +4030,7 @@ available. This feature is provided to make it easier to test expansions that make use of these variables. However, this option can be used only by an admin user. See also &%-bem%&. -.vitem &%-Mt%&&~<&'message&~id'&>&~<&'message&~id'&>&~... -.oindex "&%-Mt%&" +.cmdopt -Mt <&'message&~id'&>&~<&'message&~id'&>&~... .cindex "thawing messages" .cindex "unfreezing messages" .cindex "frozen messages" "thawing" @@ -4158,44 +4040,38 @@ This option requests Exim to &"thaw"& any of the listed messages that are messages are active, their status is not altered. This option can be used only by an admin user. -.vitem &%-Mvb%&&~<&'message&~id'&> -.oindex "&%-Mvb%&" +.cmdopt -Mvb <&'message&~id'&> .cindex "listing" "message body" .cindex "message" "listing body of" This option causes the contents of the message body (-D) spool file to be written to the standard output. This option can be used only by an admin user. -.vitem &%-Mvc%&&~<&'message&~id'&> -.oindex "&%-Mvc%&" +.cmdopt -Mvc <&'message&~id'&> .cindex "message" "listing in RFC 2822 format" .cindex "listing" "message in RFC 2822 format" This option causes a copy of the complete message (header lines plus body) to be written to the standard output in RFC 2822 format. This option can be used only by an admin user. -.vitem &%-Mvh%&&~<&'message&~id'&> -.oindex "&%-Mvh%&" +.cmdopt -Mvh <&'message&~id'&> .cindex "listing" "message headers" .cindex "header lines" "listing" .cindex "message" "listing header lines" This option causes the contents of the message headers (-H) spool file to be written to the standard output. This option can be used only by an admin user. -.vitem &%-Mvl%&&~<&'message&~id'&> -.oindex "&%-Mvl%&" +.cmdopt -Mvl <&'message&~id'&> .cindex "listing" "message log" .cindex "message" "listing message log" This option causes the contents of the message log spool file to be written to the standard output. This option can be used only by an admin user. -.vitem &%-m%& -.oindex "&%-m%&" +.cmdopt -m This is a synonym for &%-om%& that is accepted by Sendmail (&url(https://docs.oracle.com/cd/E19457-01/801-6680-1M/801-6680-1M.pdf) p. 1M-258), so Exim treats it that way too. -.vitem &%-N%& -.oindex "&%-N%&" +.cmdopt -N .cindex "debugging" "&%-N%& option" .cindex "debugging" "suppressing delivery" This is a debugging option that inhibits delivery of a message at the transport @@ -4214,27 +4090,23 @@ routing problem. Once &%-N%& has been used for a delivery attempt, it sticks to the message, and applies to any subsequent delivery attempts that may happen for that message. -.vitem &%-n%& -.oindex "&%-n%&" +.cmdopt -n This option is interpreted by Sendmail to mean &"no aliasing"&. For normal modes of operation, it is ignored by Exim. When combined with &%-bP%& it makes the output more terse (suppresses option names, environment values and config pretty printing). -.vitem &%-O%&&~<&'data'&> -.oindex "&%-O%&" +.cmdopt -O <&'data'&> This option is interpreted by Sendmail to mean &`set option`&. It is ignored by Exim. -.vitem &%-oA%&&~<&'file&~name'&> -.oindex "&%-oA%&" +.cmdopt -oA <&'file&~name'&> .cindex "Sendmail compatibility" "&%-oA%& option" This option is used by Sendmail in conjunction with &%-bi%& to specify an alternative alias filename. Exim handles &%-bi%& differently; see the description above. -.vitem &%-oB%&&~<&'n'&> -.oindex "&%-oB%&" +.cmdopt -oB <&'n'&> .cindex "SMTP" "passed connection" .cindex "SMTP" "multiple deliveries" .cindex "multiple SMTP deliveries" @@ -4242,8 +4114,7 @@ This is a debugging option which limits the maximum number of messages that can be delivered down one SMTP connection, overriding the value set in any &(smtp)& transport. If <&'n'&> is omitted, the limit is set to 1. -.vitem &%-odb%& -.oindex "&%-odb%&" +.cmdopt -odb .cindex "background delivery" .cindex "delivery" "in the background" This option applies to all modes in which Exim accepts incoming messages, @@ -4262,8 +4133,7 @@ If one of the queueing options in the configuration file overrides it if &%queue_only_override%& is set true, which is the default setting. If &%queue_only_override%& is set false, &%-odb%& has no effect. -.vitem &%-odf%& -.oindex "&%-odf%&" +.cmdopt -odf .cindex "foreground delivery" .cindex "delivery" "in the foreground" This option requests &"foreground"& (synchronous) delivery when Exim has @@ -4284,13 +4154,11 @@ process exits. See chapter &<>& for a way of setting up a restricted configuration that never queues messages. -.vitem &%-odi%& -.oindex "&%-odi%&" +.cmdopt -odi This option is synonymous with &%-odf%&. It is provided for compatibility with Sendmail. -.vitem &%-odq%& -.oindex "&%-odq%&" +.cmdopt -odq .cindex "non-immediate delivery" .cindex "delivery" "suppressing immediate" .cindex "queueing incoming messages" @@ -4303,8 +4171,7 @@ process encounters them. There are several configuration options (such as conditions. This option overrides all of them and also &%-odqs%&. It always forces queueing. -.vitem &%-odqs%& -.oindex "&%-odqs%&" +.cmdopt -odqs .cindex "SMTP" "delaying delivery" .cindex "first pass routing" This option is a hybrid between &%-odb%&/&%-odi%& and &%-odq%&. @@ -4323,8 +4190,7 @@ host can be sent in a single SMTP connection. The &%queue_smtp_domains%& configuration option has the same effect for specific domains. See also the &%-qq%& option. -.vitem &%-oee%& -.oindex "&%-oee%&" +.cmdopt -oee .cindex "error" "reporting" If an error is detected while a non-SMTP message is being received (for example, a malformed address), the error is reported to the sender in a mail @@ -4337,36 +4203,31 @@ exits with a return code of zero. If not, the return code is 2 if the problem is that the original message has no recipients, or 1 for any other error. This is the default &%-oe%&&'x'& option if Exim is called as &'rmail'&. -.vitem &%-oem%& -.oindex "&%-oem%&" +.cmdopt -oem .cindex "error" "reporting" .cindex "return code" "for &%-oem%&" This is the same as &%-oee%&, except that Exim always exits with a non-zero return code, whether or not the error message was successfully sent. This is the default &%-oe%&&'x'& option, unless Exim is called as &'rmail'&. -.vitem &%-oep%& -.oindex "&%-oep%&" +.cmdopt -oep .cindex "error" "reporting" If an error is detected while a non-SMTP message is being received, the error is reported by writing a message to the standard error file (stderr). .cindex "return code" "for &%-oep%&" The return code is 1 for all errors. -.vitem &%-oeq%& -.oindex "&%-oeq%&" +.cmdopt -oeq .cindex "error" "reporting" This option is supported for compatibility with Sendmail, but has the same effect as &%-oep%&. -.vitem &%-oew%& -.oindex "&%-oew%&" +.cmdopt -oew .cindex "error" "reporting" This option is supported for compatibility with Sendmail, but has the same effect as &%-oem%&. -.vitem &%-oi%& -.oindex "&%-oi%&" +.cmdopt -oi .cindex "dot" "in incoming non-SMTP message" This option, which has the same effect as &%-i%&, specifies that a dot on a line by itself should not terminate an incoming, non-SMTP message. Otherwise, a @@ -4374,12 +4235,10 @@ single dot does terminate, though Exim does no special processing for other lines that start with a dot. This option is set by default if Exim is called as &'rmail'&. See also &%-ti%&. -.vitem &%-oitrue%& -.oindex "&%-oitrue%&" +.cmdopt -oitrue This option is treated as synonymous with &%-oi%&. -.vitem &%-oMa%&&~<&'host&~address'&> -.oindex "&%-oMa%&" +.cmdopt -oMa <&'host&~address'&> .cindex "sender" "host address, specifying for local message" A number of options starting with &%-oM%& can be used to set values associated with remote hosts on locally-submitted messages (that is, messages not received @@ -4402,8 +4261,7 @@ port, if present, in &$sender_host_port$&. If both &%-oMa%& and &%-bh%& are present on the command line, the sender host IP address is taken from whichever one is last. -.vitem &%-oMaa%&&~<&'name'&> -.oindex "&%-oMaa%&" +.cmdopt -oMaa <&'name'&> .cindex "authentication" "name, specifying for local message" See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMaa%& option sets the value of &$sender_host_authenticated$& (the authenticator @@ -4411,8 +4269,7 @@ name). See chapter &<>& for a discussion of SMTP authentication. This option can be used with &%-bh%& and &%-bs%& to set up an authenticated SMTP session without actually using the SMTP AUTH command. -.vitem &%-oMai%&&~<&'string'&> -.oindex "&%-oMai%&" +.cmdopt -oMai <&'string'&> .cindex "authentication" "id, specifying for local message" See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMai%& option sets the value of &$authenticated_id$& (the id that was authenticated). @@ -4420,8 +4277,7 @@ This overrides the default value (the caller's login id, except with &%-bh%&, where there is no default) for messages from local sources. See chapter &<>& for a discussion of authenticated ids. -.vitem &%-oMas%&&~<&'address'&> -.oindex "&%-oMas%&" +.cmdopt -oMas <&'address'&> .cindex "authentication" "sender, specifying for local message" See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMas%& option sets the authenticated sender value in &$authenticated_sender$&. It @@ -4431,16 +4287,14 @@ default. For both &%-bh%& and &%-bs%&, an authenticated sender that is specified on a MAIL command overrides this value. See chapter &<>& for a discussion of authenticated senders. -.vitem &%-oMi%&&~<&'interface&~address'&> -.oindex "&%-oMi%&" +.cmdopt -oMi <&'interface&~address'&> .cindex "interface" "address, specifying for local message" See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMi%& option sets the IP interface address value. A port number may be included, using the same syntax as for &%-oMa%&. The interface address is placed in &$received_ip_address$& and the port number, if present, in &$received_port$&. -.vitem &%-oMm%&&~<&'message&~reference'&> -.oindex "&%-oMm%&" +.cmdopt -oMm <&'message&~reference'&> .cindex "message reference" "message reference, specifying for local message" See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMm%& option sets the message reference, e.g. message-id, and is logged during @@ -4453,8 +4307,7 @@ The best example of a message reference is when Exim sends a bounce message. The message reference is the message-id of the original message for which Exim is sending the bounce. -.vitem &%-oMr%&&~<&'protocol&~name'&> -.oindex "&%-oMr%&" +.cmdopt -oMr <&'protocol&~name'&> .cindex "protocol, specifying for local message" .vindex "&$received_protocol$&" See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMr%& @@ -4466,37 +4319,32 @@ SMTP protocol names (see the description of &$received_protocol$& in section one of those same names. For &%-bS%& (batched SMTP) however, the protocol can be set by &%-oMr%&. Repeated use of this option is not supported. -.vitem &%-oMs%&&~<&'host&~name'&> -.oindex "&%-oMs%&" +.cmdopt -oMs <&'host&~name'&> .cindex "sender" "host name, specifying for local message" See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMs%& option sets the sender host name in &$sender_host_name$&. When this option is present, Exim does not attempt to look up a host name from an IP address; it uses the name it is given. -.vitem &%-oMt%&&~<&'ident&~string'&> -.oindex "&%-oMt%&" +.cmdopt -oMt <&'ident&~string'&> .cindex "sender" "ident string, specifying for local message" See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMt%& option sets the sender ident value in &$sender_ident$&. The default setting for local callers is the login id of the calling process, except when &%-bh%& is used, when there is no default. -.vitem &%-om%& -.oindex "&%-om%&" +.cmdopt -om .cindex "Sendmail compatibility" "&%-om%& option ignored" In Sendmail, this option means &"me too"&, indicating that the sender of a message should receive a copy of the message if the sender appears in an alias expansion. Exim always does this, so the option does nothing. -.vitem &%-oo%& -.oindex "&%-oo%&" +.cmdopt -oo .cindex "Sendmail compatibility" "&%-oo%& option ignored" This option is ignored. In Sendmail it specifies &"old style headers"&, whatever that means. -.vitem &%-oP%&&~<&'path'&> -.oindex "&%-oP%&" +.cmdopt -oP <&'path'&> .cindex "pid (process id)" "of daemon" .cindex "daemon" "process id (pid)" This option is useful only in conjunction with &%-bd%& or &%-q%& with a time @@ -4505,8 +4353,7 @@ written. When &%-oX%& is used with &%-bd%&, or when &%-q%& with a time is used without &%-bd%&, this is the only way of causing Exim to write a pid file, because in those cases, the normal pid file is not used. -.vitem &%-oPX%& -.oindex "&%-oPX%&" +.cmdopt -oPX .cindex "pid (process id)" "of daemon" .cindex "daemon" "process id (pid)" This option is not intended for general use. @@ -4514,16 +4361,14 @@ The daemon uses it when terminating due to a SIGTEM, possibly in combination with &%-oP%&&~<&'path'&>. It causes the pid file to be removed. -.vitem &%-or%&&~<&'time'&> -.oindex "&%-or%&" +.cmdopt -or <&'time'&> .cindex "timeout" "for non-SMTP input" This option sets a timeout value for incoming non-SMTP messages. If it is not set, Exim will wait forever for the standard input. The value can also be set by the &%receive_timeout%& option. The format used for specifying times is described in section &<>&. -.vitem &%-os%&&~<&'time'&> -.oindex "&%-os%&" +.cmdopt -os <&'time'&> .cindex "timeout" "for SMTP input" .cindex "SMTP" "input timeout" This option sets a timeout value for incoming SMTP messages. The timeout @@ -4531,12 +4376,10 @@ applies to each SMTP command and block of data. The value can also be set by the &%smtp_receive_timeout%& option; it defaults to 5 minutes. The format used for specifying times is described in section &<>&. -.vitem &%-ov%& -.oindex "&%-ov%&" +.cmdopt -ov This option has exactly the same effect as &%-v%&. -.vitem &%-oX%&&~<&'number&~or&~string'&> -.oindex "&%-oX%&" +.cmdopt -oX <&'number&~or&~string'&> .cindex "TCP/IP" "setting listening ports" .cindex "TCP/IP" "setting listening interfaces" .cindex "port" "receiving TCP/IP" @@ -4546,8 +4389,7 @@ of the syntax, and how it interacts with configuration file options, are given in chapter &<>&. When &%-oX%& is used to start a daemon, no pid file is written unless &%-oP%& is also present to specify a pid filename. -.vitem &%-oY%& -.oindex &%-oY%& +.cmdopt -oY .cindex "daemon notifier socket" This option controls the creation of an inter-process communications endpoint by the Exim daemon. @@ -4565,16 +4407,14 @@ fast ramp-up of queue runner processes obtaining a current queue size .endlist -.vitem &%-pd%& -.oindex "&%-pd%&" +.cmdopt -pd .cindex "Perl" "starting the interpreter" This option applies when an embedded Perl interpreter is linked with Exim (see chapter &<>&). It overrides the setting of the &%perl_at_start%& option, forcing the starting of the interpreter to be delayed until it is needed. -.vitem &%-ps%& -.oindex "&%-ps%&" +.cmdopt -ps .cindex "Perl" "starting the interpreter" This option applies when an embedded Perl interpreter is linked with Exim (see chapter &<>&). It overrides the setting of the &%perl_at_start%& @@ -4594,8 +4434,7 @@ to embedded Perl. It is therefore impossible to set a protocol value of &`d`& or &`s`& using this option (but that does not seem a real limitation). Repeated use of this option is not supported. -.vitem &%-q%& -.oindex "&%-q%&" +.cmdopt -q .cindex "queue runner" "starting manually" This option is normally restricted to admin users. However, there is a configuration option called &%prod_requires_admin%& which can be set false to @@ -4811,8 +4650,7 @@ command ETRN is accepted by its ACL (see chapter &<>&), its default effect is to run Exim with the &%-R%& option, but it can be configured to run an arbitrary command instead. -.vitem &%-r%& -.oindex "&%-r%&" +.cmdopt -r This is a documented (for Sendmail) obsolete alternative name for &%-f%&. .vitem &%-S%&<&'rsflags'&>&~<&'string'&> @@ -4824,14 +4662,12 @@ message's sender instead of against the recipients. If &%-R%& is also set, both conditions must be met for a message to be selected. If either of the options has &'f'& or &'ff'& in its flags, the associated action is taken. -.vitem &%-Tqt%&&~<&'times'&> -.oindex "&%-Tqt%&" +.cmdopt -Tqt <&'times'&> This is an option that is exclusively for use by the Exim testing suite. It is not recognized when Exim is run normally. It allows for the setting up of explicit &"queue times"& so that various warning/retry features can be tested. -.vitem &%-t%& -.oindex "&%-t%&" +.cmdopt -t .cindex "recipient" "extracting from header lines" .chindex Bcc: .chindex Cc: @@ -4871,13 +4707,11 @@ are often added at the end of the header, and if a message is resent more than once, it is common for the original set of &%Resent-%& headers to be renamed as &%X-Resent-%& when a new set is added. This removes any possible ambiguity. -.vitem &%-ti%& -.oindex "&%-ti%&" +.cmdopt -ti This option is exactly equivalent to &%-t%& &%-i%&. It is provided for compatibility with Sendmail. -.vitem &%-tls-on-connect%& -.oindex "&%-tls-on-connect%&" +.cmdopt -tls-on-connect .cindex "TLS" "use without STARTTLS" .cindex "TLS" "automatic start" This option is available when Exim is compiled with TLS support. It forces all @@ -4886,16 +4720,14 @@ incoming SMTP connections to behave as if the incoming port is listed in the &<>& for further details. -.vitem &%-U%& -.oindex "&%-U%&" +.cmdopt -U .cindex "Sendmail compatibility" "&%-U%& option ignored" Sendmail uses this option for &"initial message submission"&, and its documentation states that in future releases, it may complain about syntactically invalid messages rather than fixing them when this flag is not set. Exim ignores this option. -.vitem &%-v%& -.oindex "&%-v%&" +.cmdopt -v This option causes Exim to write information to the standard error stream, describing what it is doing. In particular, it shows the log lines for receiving and delivering a message, and if an SMTP connection is made, the SMTP @@ -4904,20 +4736,17 @@ the log if the setting of &%log_selector%& discards them. Any relevant selectors are shown with each log line. If none are shown, the logging is unconditional. -.vitem &%-x%& -.oindex "&%-x%&" +.cmdopt -x AIX uses &%-x%& for a private purpose (&"mail from a local mail program has National Language Support extended characters in the body of the mail item"&). It sets &%-x%& when calling the MTA from its &%mail%& command. Exim ignores this option. -.vitem &%-X%&&~<&'logfile'&> -.oindex "&%-X%&" +.cmdopt -X <&'logfile'&> 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%&" +.cmdopt -z <&'log-line'&> 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, @@ -6730,15 +6559,17 @@ 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 &<>&, where string expansions are described in detail. -The key for the lookup is &*specified*& as part of the string expansion. +The key for the lookup is &*specified*& as part of the string to be expanded. .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 &<>&. -The key for the lookup is &*implicit*&, -given by the context in which the list is expanded. +Depending on the lookup type (see below) +the key for the lookup may need to be &*specified*& as above +or may be &*implicit*&, +given by the context in which the list is being checked. .endlist String expansions, lists, and lookups interact with each other in such a way @@ -6757,10 +6588,9 @@ Be careful to distinguish between the following two examples: domains = ${lookup{$sender_host_address}lsearch{/some/file}} domains = lsearch;/some/file .endd +.ilist The first uses a string expansion, the result of which must be a domain list. -.new The key for an expansion-style lookup must be given explicitly. -.wen No strings have been specified for a successful or a failing lookup; the defaults in this case are the looked-up data and an empty string, respectively. The expansion takes place before the string is processed as a list, and the @@ -6772,8 +6602,10 @@ file that is searched could contain lines like this: When the lookup succeeds, the result of the expansion is a list of domains (and possibly other types of item that are allowed in domain lists). .cindex "tainted data" "de-tainting" +.cindex "de-tainting" "using a lookup expansion" The result of the expansion is not tainted. +.next In the second example, the lookup is a single item in a domain list. It causes Exim to use a lookup to see if the domain that is being processed can be found in the file. @@ -6785,11 +6617,10 @@ domain2: Any data that follows the keys is not relevant when checking that the domain matches the list item. -.new The key for a list-style lookup is implicit, from the lookup context, if the lookup is a single-key type (see below). -For query-style lookup types the key must be given explicitly. -.wen +For query-style lookup types the query must be given explicitly. +.endlist It is possible, though no doubt confusing, to use both kinds of lookup at once. Consider a file containing lines like this: @@ -6828,23 +6659,22 @@ lookup to succeed. The lookup type determines how the file is searched. The file string may not be tainted. .cindex "tainted data" "de-tainting" +.cindex "de-tainting" "using a single-key lookup" All single-key lookups support the option &"ret=key"&. If this is given and the lookup (either underlying implementation or cached value) returns data, the result is replaced with a non-tainted version of the lookup key. -.cindex "tainted data" "de-tainting" + .next .cindex "query-style lookup" "definition of" The &'query-style'& type accepts a generalized database query. No particular key value is assumed by Exim for query-style lookups. You can use whichever Exim variables you need to construct the database query. .cindex "tainted data" "quoting for lookups" -.new If tainted data is used in the query then it should be quuted by using the &*${quote_*&<&'lookup-type'&>&*:*&<&'string'&>&*}*& expansion operator appropriate for the lookup. -.wen .endlist The code for each lookup type is in a separate source file that is included in @@ -6866,11 +6696,11 @@ libraries and header files before building Exim. .cindex "single-key lookup" "list of types" The following single-key lookup types are implemented: -.ilist +.subsection cdb .cindex "cdb" "description of" .cindex "lookup" "cdb" .cindex "binary zero" "in lookup key" -&(cdb)&: The given file is searched as a Constant DataBase file, using the key +The given file is searched as a Constant DataBase file, using the key string without a terminating binary zero. The cdb format is designed for indexed files that are read frequently and never updated, except by total re-creation. As such, it is particularly suitable for large files containing @@ -6886,11 +6716,12 @@ A cdb distribution is not needed in order to build Exim with cdb support, because the code for reading cdb files is included directly in Exim itself. However, no means of building or testing cdb files is provided with Exim, so you need to obtain a cdb distribution in order to do this. -.next + +.subsection dbm .cindex "DBM" "lookup type" .cindex "lookup" "dbm" .cindex "binary zero" "in lookup key" -&(dbm)&: Calls to DBM library functions are used to extract data from the given +Calls to DBM library functions are used to extract data from the given DBM file by looking up the record with the given key. A terminating binary zero is included in the key that is passed to the DBM library. See section &<>& for a discussion of DBM libraries. @@ -6902,25 +6733,27 @@ using Berkeley DB versions 3 or 4, it opens existing databases for reading with the DB_UNKNOWN option. This enables it to handle any of the types of database that the library supports, and can be useful for accessing DBM files created by other applications. (For earlier DB versions, DB_HASH is always used.) -.next + +.subsection dbmjz .cindex "lookup" "dbmjz" .cindex "lookup" "dbm &-- embedded NULs" .cindex "sasldb2" .cindex "dbmjz lookup type" -&(dbmjz)&: This is the same as &(dbm)&, except that the lookup key is +This is the same as &(dbm)&, except that the lookup key is interpreted as an Exim list; the elements of the list are joined together with ASCII NUL characters to form the lookup key. An example usage would be to authenticate incoming SMTP calls using the passwords from Cyrus SASL's &_/etc/sasldb2_& file with the &(gsasl)& authenticator or Exim's own &(cram_md5)& authenticator. -.next + +.subsection dbmnz .cindex "lookup" "dbmnz" .cindex "lookup" "dbm &-- terminating zero" .cindex "binary zero" "in lookup key" .cindex "Courier" .cindex "&_/etc/userdbshadow.dat_&" .cindex "dbmnz lookup type" -&(dbmnz)&: This is the same as &(dbm)&, except that a terminating binary zero +This is the same as &(dbm)&, except that a terminating binary zero is not included in the key that is passed to the DBM library. You may need this if you want to look up data in files that are created by or shared with some other application that does not use terminating zeros. For example, you need to @@ -6928,15 +6761,13 @@ use &(dbmnz)& rather than &(dbm)& if you want to authenticate incoming SMTP calls using the passwords from Courier's &_/etc/userdbshadow.dat_& file. Exim's utility program for creating DBM files (&'exim_dbmbuild'&) includes the zeros by default, but has an option to omit them (see section &<>&). -.next + +.subsection dsearch .cindex "lookup" "dsearch" .cindex "dsearch lookup type" -&(dsearch)&: The given file must be an -absolute -directory path; this is searched for an entry +The given file must be an absolute directory path; this is searched for an entry whose name is the key by calling the &[lstat()]& function. -The key may not -contain any forward slash characters. +The key may not contain any forward slash characters. If &[lstat()]& succeeds then so does the lookup. .cindex "tainted data" "dsearch result" The result is regarded as untainted. @@ -6965,10 +6796,11 @@ and symlinks. An example of how this lookup can be used to support virtual domains is given in section &<>&. -.next + +.subsection iplsearch .cindex "lookup" "iplsearch" .cindex "iplsearch lookup type" -&(iplsearch)&: The given file is a text file containing keys and data. A key is +The given file is a text file containing keys and data. A key is terminated by a colon or white space or the end of the line. The keys in the file must be IP addresses, or IP addresses with CIDR masks. Keys that involve IPv6 addresses must be enclosed in quotes to prevent the first internal colon @@ -7001,11 +6833,11 @@ One option is supported, "ret=full", to request the return of the entire line rather than omitting the key portion. Note however that the key portion will have been de-quoted. -.next +.subsection json .cindex lookup json .cindex json "lookup type" .cindex JSON expansions -&(json)&: The given file is a text file with a JSON structure. +The given file is a text file with a JSON structure. An element of the structure is extracted, defined by the search key. The key is a list of subelement selectors (colon-separated by default but changeable in the usual way) @@ -7020,11 +6852,11 @@ is returned. For elements of type string, the returned value is de-quoted. -.next +.subsection lmdb .cindex LMDB .cindex lookup lmdb .cindex database lmdb -&(lmdb)&: The given file is an LMDB database. +The given file is an LMDB database. LMDB is a memory-mapped key-value store, with API modeled loosely on that of BerkeleyDB. See &url(https://symas.com/products/lightning-memory-mapped-database/) @@ -7039,12 +6871,12 @@ You will need to separately create the LMDB database file, possibly using the &"mdb_load"& utility. -.next +.subsection lsearch .cindex "linear search" .cindex "lookup" "lsearch" .cindex "lsearch lookup type" .cindex "case sensitivity" "in lsearch lookup" -&(lsearch)&: The given file is a text file that is searched linearly for a +The given file is a text file that is searched linearly for a line beginning with the search key, terminated by a colon or white space or the end of the line. The search is case-insensitive; that is, upper and lower case letters are treated as the same. The first occurrence of the key that is found @@ -7074,17 +6906,17 @@ contents (see section &<>&). An optional colon is permitted after quoted keys (exactly as for unquoted keys). There is no special handling of quotes for the data part of an &(lsearch)& line. -.next +.subsection nis .cindex "NIS lookup type" .cindex "lookup" "NIS" .cindex "binary zero" "in lookup key" -&(nis)&: The given file is the name of a NIS map, and a NIS lookup is done with +The given file is the name of a NIS map, and a NIS lookup is done with the given key, without a terminating binary zero. There is a variant called &(nis0)& which does include the terminating binary zero in the key. This is reportedly needed for Sun-style alias files. Exim does not recognize NIS aliases; the full map names must be used. -.next +.subsection (n)wildlsearch .cindex "wildlsearch lookup type" .cindex "lookup" "wildlsearch" .cindex "nwildlsearch lookup type" @@ -7100,32 +6932,29 @@ Like &(lsearch)&, the testing is done case-insensitively. However, keys in the file that are regular expressions can be made case-sensitive by the use of &`(-i)`& within the pattern. The following forms of wildcard are recognized: -. ==== As this is a nested list, any displays it contains must be indented -. ==== as otherwise they are too far to the left. - .olist The string may begin with an asterisk to mean &"ends with"&. For example: .code - *.a.b.c data for anything.a.b.c - *fish data for anythingfish +*.a.b.c data for anything.a.b.c +*fish data for anythingfish .endd .next The string may begin with a circumflex to indicate a regular expression. For example, for &(wildlsearch)&: .code - ^\N\d+\.a\.b\N data for .a.b +^\N\d+\.a\.b\N data for .a.b .endd Note the use of &`\N`& to disable expansion of the contents of the regular expression. If you are using &(nwildlsearch)&, where the keys are not string-expanded, the equivalent entry is: .code - ^\d+\.a\.b data for .a.b +^\d+\.a\.b data for .a.b .endd The case-insensitive flag is set at the start of compiling the regular expression, but it can be turned off by using &`(-i)`& at an appropriate point. For example, to make the entire pattern case-sensitive: .code - ^(?-i)\d+\.a\.b data for .a.b +^(?-i)\d+\.a\.b data for .a.b .endd If the regular expression contains white space or colon characters, you must @@ -7146,7 +6975,7 @@ is used to implement &((n)wildlsearch)& means that the string may begin with a lookup name terminated by a semicolon, and followed by lookup data. For example: .code - cdb;/some/file data for keys that match the file +cdb;/some/file data for keys that match the file .endd The data that is obtained from the nested lookup is discarded. .endlist olist @@ -7159,13 +6988,12 @@ be followed by optional colons. &((n)wildlsearch)& can &'not'& be turned into a DBM or cdb file, because those lookup types support only literal keys. -.next +.subsection spf .cindex "spf lookup type" .cindex "lookup" "spf" -&(spf)&: If Exim is built with SPF support, manual lookups can be done +If Exim is built with SPF support, manual lookups can be done (as opposed to the standard ACL condition method). For details see section &<>&. -.endlist ilist .section "Query-style lookup types" "SECTquerystylelookups" @@ -7174,44 +7002,50 @@ For details see section &<>&. The supported query-style lookup types are listed below. Further details about many of them are given in later sections. -.ilist +.subsection dnsdb .cindex "DNS" "as a lookup type" .cindex "lookup" "DNS" -&(dnsdb)&: This does a DNS search for one or more records whose domain names +This does a DNS search for one or more records whose domain names are given in the supplied query. The resulting data is the contents of the records. See section &<>&. -.next + +.subsection ibase .cindex "InterBase lookup type" .cindex "lookup" "InterBase" -&(ibase)&: This does a lookup in an InterBase database. -.next +This does a lookup in an InterBase database. + +.subsection ldap .cindex "LDAP" "lookup type" .cindex "lookup" "LDAP" -&(ldap)&: This does an LDAP lookup using a query in the form of a URL, and +This does an LDAP lookup using a query in the form of a URL, and returns attributes from a single entry. There is a variant called &(ldapm)& that permits values from multiple entries to be returned. A third variant called &(ldapdn)& returns the Distinguished Name of a single entry instead of any attribute values. See section &<>&. -.next + +.subsection mysql .cindex "MySQL" "lookup type" .cindex "lookup" "MySQL" -&(mysql)&: The format of the query is an SQL statement that is passed to a +The format of the query is an SQL statement that is passed to a MySQL database. See section &<>&. -.next + +.subsection nisplus .cindex "NIS+ lookup type" .cindex "lookup" "NIS+" -&(nisplus)&: This does a NIS+ lookup using a query that can specify the name of +This does a NIS+ lookup using a query that can specify the name of the field to be returned. See section &<>&. -.next + +.subsection oracle .cindex "Oracle" "lookup type" .cindex "lookup" "Oracle" -&(oracle)&: The format of the query is an SQL statement that is passed to an +The format of the query is an SQL statement that is passed to an Oracle database. See section &<>&. -.next + +.subsection passwd .cindex "lookup" "passwd" .cindex "passwd lookup type" .cindex "&_/etc/passwd_&" -&(passwd)& is a query-style lookup with queries that are just user names. The +This is a query-style lookup with queries that are just user names. The lookup calls &[getpwnam()]& to interrogate the system password data, and on success, the result string is the same as you would get from an &(lsearch)& lookup on a traditional &_/etc/passwd file_&, though with &`*`& for the @@ -7219,32 +7053,33 @@ password value. For example: .code *:42:42:King Rat:/home/kr:/bin/bash .endd -.next + +.subsection pgsql .cindex "PostgreSQL lookup type" .cindex "lookup" "PostgreSQL" -&(pgsql)&: The format of the query is an SQL statement that is passed to a +The format of the query is an SQL statement that is passed to a PostgreSQL database. See section &<>&. -.next +.subsection redis .cindex "Redis lookup type" .cindex lookup Redis -&(redis)&: The format of the query is either a simple get or simple set, +The format of the query is either a simple get or simple set, passed to a Redis database. See section &<>&. -.next +.subsection sqlite .cindex "sqlite lookup type" .cindex "lookup" "sqlite" -&(sqlite)&: The format of the query is +The format of the query is an SQL statement that is passed to an SQLite database. See section &<>&. -.next -&(testdb)&: This is a lookup type that is used for testing Exim. It is +.subsection testdb +This is a lookup type that is used for testing Exim. It is not likely to be useful in normal operation. -.next + +.subsection whoson .cindex "whoson lookup type" .cindex "lookup" "whoson" -. --- still http:-only, 2018-09-07 -&(whoson)&: &'Whoson'& (&url(http://whoson.sourceforge.net)) is a protocol that +&'Whoson'& (&url(http://whoson.sourceforge.net)) is a protocol that allows a server to check whether a particular (dynamically allocated) IP address is currently allocated to a known (trusted) user and, optionally, to obtain the identity of the said user. For SMTP servers, &'Whoson'& was popular @@ -7259,7 +7094,6 @@ The query consists of a single IP address. The value returned is the name of the authenticated user, which is stored in the variable &$value$&. However, in this example, the data in &$value$& is not used; the result of the lookup is one of the fixed strings &"yes"& or &"no"&. -.endlist @@ -7562,7 +7396,7 @@ specified. ${lookup dnsdb{>:,; soa=a.b.example.com}} .endd -.section "Dnsdb lookup modifiers" "SECTdnsdb_mod" +.subsection "Dnsdb lookup modifiers" SECTdnsdb_mod .cindex "dnsdb modifiers" .cindex "modifiers" "dnsdb" .cindex "options" "dnsdb" @@ -7620,7 +7454,7 @@ The cache entry lifetime is limited to the smallest time-to-live (TTL) value of the set of returned DNS records. -.section "Pseudo dnsdb record types" "SECID66" +.subsection "Pseudo dnsdb record types" SECID66 .cindex "MX record" "in &(dnsdb)& lookup" By default, both the preference value and the host name are returned for each MX record, separated by a space. If you want only host names, you can use @@ -7676,7 +7510,7 @@ ${lookup dnsdb {>; a+=$sender_helo_name}} .endd -.section "Multiple dnsdb lookups" "SECID67" +.subsection "Multiple dnsdb lookups" SECID67 In the previous sections, &(dnsdb)& lookups for a single domain are described. However, you can specify a list of domains or IP addresses in a single &(dnsdb)& lookup. The list is specified in the normal Exim way, with colon as @@ -7741,7 +7575,7 @@ the data returned by a successful lookup is described in the next section. First we explain how LDAP queries are coded. -.section "Format of LDAP queries" "SECTforldaque" +.subsection "Format of LDAP queries" SECTforldaque .cindex "LDAP" "query format" An LDAP query takes the form of a URL as defined in RFC 2255. For example, in the configuration of a &(redirect)& router one might have this setting: @@ -7770,7 +7604,7 @@ methods become optional, only taking effect if not specifically set in &_exim.conf_&. -.section "LDAP quoting" "SECID68" +.subsection "LDAP quoting" SECID68 .cindex "LDAP" "quoting" Two levels of quoting are required in LDAP queries, the first for LDAP itself and the second because the LDAP query is represented as a URL. Furthermore, @@ -7827,7 +7661,7 @@ There are some further comments about quoting in the section on LDAP authentication below. -.section "LDAP connections" "SECID69" +.subsection "LDAP connections" SECID69 .cindex "LDAP" "connections" The connection to an LDAP server may either be over TCP/IP, or, when OpenLDAP is in use, via a Unix domain socket. The example given above does not specify @@ -7901,7 +7735,7 @@ Using &`ldapi`& with no host or path in the query, and no setting of -.section "LDAP authentication and control information" "SECID70" +.subsection "LDAP authentication and control information" SECID70 .cindex "LDAP" "authentication" The LDAP URL syntax provides no way of passing authentication and other control information to the server. To make this possible, the URL in an LDAP query may @@ -7909,16 +7743,16 @@ be preceded by any number of <&'name'&>=<&'value'&> settings, separated by spaces. If a value contains spaces it must be enclosed in double quotes, and when double quotes are used, backslash is interpreted in the usual way inside them. The following names are recognized: -.display -&`DEREFERENCE`& set the dereferencing parameter -&`NETTIME `& set a timeout for a network operation -&`USER `& set the DN, for authenticating the LDAP bind -&`PASS `& set the password, likewise -&`REFERRALS `& set the referrals parameter -&`SERVERS `& set alternate server list for this query only -&`SIZE `& set the limit for the number of entries returned -&`TIME `& set the maximum waiting time for a query -.endd +.itable none 0 0 2 20* left 80* left +.irow DEREFERENCE "set the dereferencing parameter" +.irow NETTIME "set a timeout for a network operation" +.irow USER "set the DN, for authenticating the LDAP bind" +.irow PASS "set the password, likewise" +.irow REFERRALS "set the referrals parameter" +.irow SERVERS "set alternate server list for this query only" +.irow SIZE "set the limit for the number of entries returned" +.irow TIME "set the maximum waiting time for a query" +.endtable The value of the DEREFERENCE parameter must be one of the words &"never"&, &"searching"&, &"finding"&, or &"always"&. The value of the REFERRALS parameter must be &"follow"& (the default) or &"nofollow"&. The latter stops the LDAP @@ -7995,7 +7829,7 @@ SMTP authentication. See the &%ldapauth%& expansion string condition in chapter -.section "Format of data returned by LDAP" "SECID71" +.subsection "Format of data returned by LDAP" SECID71 .cindex "LDAP" "returned data formats" The &(ldapdn)& lookup type returns the Distinguished Name from a single entry as a sequence of values, for example @@ -8129,7 +7963,7 @@ If the result of the query yields more than one row, it is all concatenated, with a newline between the data for each row. -.section "More about MySQL, PostgreSQL, Oracle, InterBase, and Redis" "SECID72" +.subsection "More about MySQL, PostgreSQL, Oracle, InterBase, and Redis" SECID72 .cindex "MySQL" "lookup type" .cindex "PostgreSQL lookup type" .cindex "lookup" "MySQL" @@ -8199,7 +8033,7 @@ itself are escaped with backslashes. The &%quote_redis%& expansion operator escapes whitespace and backslash characters with a backslash. -.section "Specifying the server in the query" "SECTspeserque" +.subsection "Specifying the server in the query" SECTspeserque For MySQL, PostgreSQL and Redis lookups (but not currently for Oracle and InterBase), it is possible to specify a list of servers with an individual query. This is done by appending a comma-separated option to the query type: @@ -8249,7 +8083,7 @@ arguments in the query, for explicit expansion. &*Note*&: server specifications in list-style lookups are still problematic. -.section "Special MySQL features" "SECID73" +.subsection "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. @@ -8274,7 +8108,7 @@ anything (for example, setting a field to the value it already has), the result is zero because no rows are affected. -.section "Special PostgreSQL features" "SECID74" +.subsection "Special PostgreSQL features" SECID74 PostgreSQL lookups can also use Unix domain socket connections to the database. This is usually faster and costs less CPU time than a TCP/IP connection. However it can be used only if the mail server runs on the same machine as the @@ -8291,7 +8125,7 @@ If a PostgreSQL query is issued that does not request any data (an insert, update, or delete command), the result of the lookup is the number of rows affected. -.section "More about SQLite" "SECTsqlite" +.subsection "More about SQLite" SECTsqlite .cindex "lookup" "SQLite" .cindex "sqlite lookup type" SQLite is different to the other SQL lookups because a filename is required in @@ -8342,7 +8176,7 @@ waits for the lock to be released. In Exim, the default timeout is set to 5 seconds, but it can be changed by means of the &%sqlite_lock_timeout%& option. -.section "More about Redis" "SECTredis" +.subsection "More about Redis" SECTredis .cindex "lookup" "Redis" .cindex "redis lookup type" Redis is a non-SQL database. Commands are simple get and set. @@ -8391,6 +8225,34 @@ domain, host, address and local part lists. +.section "Results of list checking" SECTlistresults +The primary result of doing a list check is a truth value. +In some contexts additional information is stored +about the list element that matched: +.vlist +.vitem hosts +A &%hosts%& ACL condition +will store a result in the &$host_data$& variable. +.vitem local_parts +A &%local_parts%& router option or &%local_parts%& ACL condition +will store a result in the &$local_part_data$& variable. +.vitem domains +A &%domains%& router option or &%domains%& ACL condition +will store a result in the &$domain_data$& variable. +.vitem senders +A &%senders%& router option or &%senders%& ACL condition +will store a result in the &$sender_data$& variable. +.vitem recipients +A &%recipients%& ACL condition +will store a result in the &$recipient_data$& variable. +.endlist + +The detail of the additional information depends on the +type of match and is given below as the &*value*& information. + + + + .section "Expansion of lists" "SECTlistexpand" .cindex "expansion" "of lists" Each list is expanded as a single string before it is used. @@ -8426,7 +8288,7 @@ senders based on the receiving domain. -.section "Negated items in lists" "SECID76" +.subsection "Negated items in lists" SECID76 .cindex "list" "negation" .cindex "negation" "in lists" Items in a list may be positive or negative. Negative items are indicated by a @@ -8459,7 +8321,7 @@ item. -.section "File names in lists" "SECTfilnamlis" +.subsection "File names in lists" SECTfilnamlis .cindex "list" "filename in" If an item in a domain, host, address, or local part list is an absolute filename (beginning with a slash character), each line of the file is read and @@ -8501,7 +8363,7 @@ any domain matching &`*.b.c`& is not. -.section "An lsearch file is not an out-of-line list" "SECID77" +.subsection "An lsearch file is not an out-of-line list" SECID77 As will be described in the sections that follow, lookups can be used in lists to provide indexed methods of checking list membership. There has been some confusion about the way &(lsearch)& lookups work in lists. Because @@ -8518,35 +8380,7 @@ in the previous section. You could also use the &(wildlsearch)& or -.section "Results of list checking" SECTlistresults -The primary result of doing a list check is a truth value. -In some contexts additional information is stored -about the list element that matched: -.vlist -.vitem hosts -A &%hosts%& ACL condition -will store a result in the &$host_data$& variable. -.vitem local_parts -A &%local_parts%& router option or &%local_parts%& ACL condition -will store a result in the &$local_part_data$& variable. -.vitem domains -A &%domains%& router option or &%domains%& ACL condition -will store a result in the &$domain_data$& variable. -.vitem senders -A &%senders%& router option or &%senders%& ACL condition -will store a result in the &$sender_data$& variable. -.vitem recipients -A &%recipients%& ACL condition -will store a result in the &$recipient_data$& variable. -.endlist - -The detail of the additional information depends on the -type of match and is given below as the &*value*& information. - - - - -.section "Named lists" "SECTnamedlists" +.subsection "Named lists" SECTnamedlists .cindex "named lists" .cindex "list" "named" A list of domains, hosts, email addresses, or local parts can be given a name @@ -8635,7 +8469,7 @@ hosts. The default configuration is set up like this. -.section "Named lists compared with macros" "SECID78" +.subsection "Named lists compared with macros" SECID78 .cindex "list" "named compared with macro" .cindex "macro" "compared with named list" At first sight, named lists might seem to be no different from macros in the @@ -8661,7 +8495,7 @@ auth_advertise_hosts = !host1 : !host2 .endd -.section "Named list caching" "SECID79" +.subsection "Named list caching" SECID79 .cindex "list" "caching of named" .cindex "caching" "named lists" While processing a message, Exim caches the result of checking a named list if @@ -8833,6 +8667,7 @@ or a &%domains%& condition in an ACL statement, the value is preserved in the &$domain_data$& variable and can be referred to in other router options or other statements in the same ACL. .cindex "tainted data" "de-tainting" +.cindex "de-tainting" "using ACL domains condition" The value will be untainted. &*Note*&: If the data result of the lookup (as opposed to the key) @@ -8874,6 +8709,7 @@ whether or not the query succeeds. However, when a lookup is used for the &%domains%& option on a router, the value is preserved in the &$domain_data$& variable and can be referred to in other options. .cindex "tainted data" "de-tainting" +.cindex "de-tainting" "using router domains option" The value will be untainted. .next @@ -8934,7 +8770,7 @@ You need to be particularly careful with this when single-key lookups are involved, to ensure that the right value is being used as the key. -.section "Special host list patterns" "SECID80" +.subsection "Special host list patterns" SECID80 .cindex "empty item in hosts list" .cindex "host list" "empty string in" If a host list item is the empty string, it matches only when no remote host is @@ -8948,7 +8784,7 @@ the IP address nor the name is actually inspected. -.section "Host list patterns that match by IP address" "SECThoslispatip" +.subsection "Host list patterns that match by IP address" SECThoslispatip .cindex "host list" "matching IP addresses" If an IPv4 host calls an IPv6 host and the call is accepted on an IPv6 socket, the incoming address actually appears in the IPv6 host as @@ -9051,8 +8887,8 @@ list. -.section "Host list patterns for single-key lookups by host address" &&& - "SECThoslispatsikey" +.subsection "Host list patterns for single-key lookups by host address" &&& + SECThoslispatsikey .cindex "host list" "lookup of IP address" When a host is to be identified by a single-key lookup of its complete IP address, the pattern takes this form: @@ -9111,7 +8947,7 @@ case the IP address is used on its own. -.section "Host list patterns that match by host name" "SECThoslispatnam" +.subsection "Host list patterns that match by host name" SECThoslispatnam .cindex "host" "lookup failures" .cindex "unknown host name" .cindex "host list" "matching host name" @@ -9186,7 +9022,7 @@ required. -.section "Behaviour when an IP address or name cannot be found" "SECTbehipnot" +.subsection "Behaviour when an IP address or name cannot be found" SECTbehipnot .cindex "host" "lookup failures, permanent" While processing a host list, Exim may need to look up an IP address from a name (see section &<>&), or it may need to look up a host name @@ -9232,8 +9068,8 @@ Both &`+include_unknown`& and &`+ignore_unknown`& may appear in the same list. The effect of each one lasts until the next, or until the end of the list. -.section "Mixing wildcarded host names and addresses in host lists" &&& - "SECTmixwilhos" +.subsection "Mixing wildcarded host names and addresses in host lists" &&& + SECTmixwilhos .cindex "host list" "mixing names and addresses in" This section explains the host/ip processing logic with the same concepts @@ -9269,8 +9105,8 @@ this section. .endlist -.section "Temporary DNS errors when looking up host information" &&& - "SECTtemdnserr" +.subsection "Temporary DNS errors when looking up host information" &&& + SECTtemdnserr .cindex "host" "lookup failures, temporary" .cindex "&`+include_defer`&" .cindex "&`+ignore_defer`&" @@ -9283,8 +9119,8 @@ host lists such as whitelists. -.section "Host list patterns for single-key lookups by host name" &&& - "SECThoslispatnamsk" +.subsection "Host list patterns for single-key lookups by host name" &&& + SECThoslispatnamsk .cindex "unknown host name" .cindex "host list" "matching host name" If a pattern is of the form @@ -9308,7 +9144,7 @@ lookup, both using the same file. -.section "Host list patterns for query-style lookups" "SECID81" +.subsection "Host list patterns for query-style lookups" SECID81 If a pattern is of the form .display <&'query-style-search-type'&>;<&'query'&> @@ -9540,7 +9376,7 @@ example it is a named domain list. -.section "Case of letters in address lists" "SECTcasletadd" +.subsection "Case of letters in address lists" SECTcasletadd .cindex "case of local parts" .cindex "address list" "case forcing" .cindex "case forcing in address lists" @@ -9687,6 +9523,17 @@ value. Nevertheless the &%-be%& option can be useful for checking out file and database lookups, and the use of expansion operators such as &%sg%&, &%substr%& and &%nhash%&. +.new +When reading lines from the standard input, +macros can be defined and ACL variables can be set. +For example: +.code +MY_MACRO = foo +set acl_m_myvar = bar +.endd +Such macros and variables can then be used in later input lines. +.wen + Exim gives up its root privilege when it is called with the &%-be%& option, and instead runs under the uid and gid it was called with, to prevent users from using &%-be%& for reading files to which they do not have access. @@ -10060,7 +9907,11 @@ After expansion, <&'string'&> is interpreted as a list, colon-separated by default, but the separator can be changed in the usual way (&<>&). For each item in this list, its value is place in &$item$&, and then the condition is -evaluated. If the condition is true, &$item$& is added to the output as an +evaluated. +.new +Any modification of &$value$& by this evaluation is discarded. +.wen +If the condition is true, &$item$& is added to the output as an item in a new list; if the condition is false, the item is discarded. The separator used for the output list is the same as the one used for the input, but a separator setting is not included in the output. For example: @@ -10068,7 +9919,8 @@ input, but a separator setting is not included in the output. For example: ${filter{a:b:c}{!eq{$item}{b}}} .endd yields &`a:c`&. At the end of the expansion, the value of &$item$& is restored -to what it was before. See also the &%map%& and &%reduce%& expansion items. +to what it was before. +See also the &%map%& and &%reduce%& expansion items. .vitem &*${hash{*&<&'string1'&>&*}{*&<&'string2'&>&*}{*&<&'string3'&>&*}}*& @@ -10659,20 +10511,45 @@ At the end of a &*reduce*& expansion, the values of &$item$& and &$value$& are restored to what they were before. See also the &%filter%& and &%map%& expansion items. +. A bit of a special-case logic error in writing an expansion; +. probably not worth including in the mainline of documentation. +. If only we had footnotes (the html output variant is the problem). +. +. .new +. &*Note*&: if an &'expansion condition'& is used in <&'string3'&> +. and that condition modifies &$value$&, +. then the string expansions dependent on the condition cannot use +. the &$value$& of the reduce iteration. +. .wen + .vitem &*$rheader_*&<&'header&~name'&>&*:*&&~or&~&*$rh_*&<&'header&~name'&>&*:*& This item inserts &"raw"& header lines. It is described with the &%header%& expansion item in section &<>& above. -.vitem "&*${run{*&<&'command'&>&*&~*&<&'args'&>&*}{*&<&'string1'&>&*}&&& +.vitem "&*${run <&'options'&> {*&<&'command&~arg&~list'&>&*}{*&<&'string1'&>&*}&&& {*&<&'string2'&>&*}}*&" .cindex "expansion" "running a command" .cindex "&%run%& expansion item" -The command and its arguments are first expanded as one string. The string is -split apart into individual arguments by spaces, and then the command is run +This item runs an external command, as a subprocess. +One option is supported after the word &'run'&, comma-separated. + +If the option &'preexpand'& is not used, +the command string is split into individual arguments by spaces +and then each argument is expanded. +Then the command is run in a separate process, but under the same uid and gid. As in other command executions from Exim, a shell is not used by default. If the command requires a shell, you must explicitly code it. +The command name may not be tainted, but the remaining arguments can be. + +&*Note*&: if tainted arguments are used, they are supplied by a +potential attacker; +a careful assessment for security vulnerabilities should be done. +If the option &'preexpand'& is used, +the command and its arguments are first expanded as one string. The result is +split apart into individual arguments by spaces, and then the command is run +as above. Since the arguments are split by spaces, when there is a variable expansion which has an empty result, it will cause the situation that the argument will simply be omitted when the program is actually executed by Exim. If the @@ -10683,6 +10560,7 @@ in a string containing quotes, because it would interfere with the quotes around the command arguments. A possible guard against this is to wrap the variable in the &%sg%& operator to change any quote marks to some other character. +Neither the command nor any argument may be tainted. The standard input for the command exists, but is empty. The standard output and standard error are set to the same file descriptor. @@ -10800,16 +10678,16 @@ SRS encoding. See SECT &<>& for details. -.vitem &*${substr{*&<&'string1'&>&*}{*&<&'string2'&>&*}{*&<&'string3'&>&*}}*& +.vitem &*${substr{*&<&'start'&>&*}{*&<&'len'&>&*}{*&<&'subject'&>&*}}*& .cindex "&%substr%& expansion item" .cindex "substring extraction" .cindex "expansion" "substring extraction" The three strings are expanded; the first two must yield numbers. Call them <&'n'&> and <&'m'&>. If you are using fixed values for these numbers, that is, -if <&'string1'&> and <&'string2'&> do not change when they are expanded, you +if <&'start'&> and <&'len'&> do not change when they are expanded, you can use the simpler operator notation that avoids some of the braces: .code -${substr__:} +${substr__:} .endd The second number is optional (in both notations). If it is absent in the simpler format, the preceding underscore must also be @@ -11248,9 +11126,7 @@ returns the string &"10.111.131.192/28"&. Since this operation is expected to be mostly used for looking up masked addresses in files, the -.new normal -.wen result for an IPv6 address uses dots to separate components instead of colons, because colon terminates a key string in lsearch files. So, for example, @@ -11261,10 +11137,8 @@ returns the string .code 3ffe.ffff.836f.0a00.000a.0800.2000.0000/99 .endd -.new If the optional form &*mask_n*& is used, IPv6 address result are instead returned in normailsed form, using colons and with zero-compression. -.wen Letters in IPv6 addresses are always output in lower case. @@ -11596,14 +11470,14 @@ condition. .cindex "expansion" "numeric comparison" There are a number of symbolic operators for doing numeric comparisons. They are: -.display -&`= `& equal -&`== `& equal -&`> `& greater -&`>= `& greater or equal -&`< `& less -&`<= `& less or equal -.endd +.itable none 0 0 2 10* left 90* left +.irow "= " "equal" +.irow "== " "equal" +.irow "> " "greater" +.irow ">= " "greater or equal" +.irow "< " "less" +.irow "<= " "less or equal" +.endtable For example: .code ${if >{$message_size}{10M} ... @@ -11800,6 +11674,7 @@ Consider using a dsearch lookup. .cindex "first delivery" .cindex "expansion" "first delivery test" .cindex "&%first_delivery%& expansion condition" +.cindex retry condition This condition, which has no data, is true during a message's first delivery attempt. It is false during any subsequent delivery attempts. @@ -11902,6 +11777,18 @@ ${if inlisti{Needle}{fOo:NeeDLE:bAr}} ${if forany{fOo:NeeDLE:bAr}{eqi{$item}{Needle}}} .endd +The variable &$value$& will be set for a successful match and can be +used in the success clause of an &%if%& expansion item using the condition. +.cindex "tainted data" "de-tainting" +.cindex "de-tainting" "using an inlist expansion condition" +It will have the same taint status as the list; expansions such as +.code +${if inlist {$h_mycode:} {0 : 1 : 42} {$value}} +.endd +can be used for de-tainting. +Any previous &$value$& is restored after the if. + + .vitem &*isip&~{*&<&'string'&>&*}*& &&& &*isip4&~{*&<&'string'&>&*}*& &&& &*isip6&~{*&<&'string'&>&*}*& @@ -12098,6 +11985,17 @@ item can be used, as in all address lists, to cause subsequent items to have their local parts matched casefully. Domains are always matched caselessly. +The variable &$value$& will be set for a successful match and can be +used in the success clause of an &%if%& expansion item using the condition. +.cindex "tainted data" "de-tainting" +.cindex "de-tainting" "using a match_local_part expansion condition" +It will have the same taint status as the list; expansions such as +.code +${if match_local_part {$local_part} {alice : bill : charlotte : dave} {$value}} +.endd +can be used for de-tainting. +Any previous &$value$& is restored after the if. + Note that <&'string2'&> is not itself subject to string expansion, unless Exim was built with the EXPAND_LISTMATCH_RHS option. @@ -12293,6 +12191,14 @@ parsed but not evaluated. This section contains an alphabetical list of all the expansion variables. Some of them are available only when Exim is compiled with specific options such as support for TLS or the content scanning extension. +.cindex "tainted data" +Variables marked as &'tainted'& are likely to carry data supplied by +a potential attacker. +Variables without such marking may also, depending on how their +values are created. +Such variables should not be further expanded, +used as filenames +or used as command-line arguments for external commands. .vlist .vitem "&$0$&, &$1$&, etc" @@ -12307,6 +12213,7 @@ variables may also be set externally by some other matching process which precedes the expansion of the string. For example, the commands available in Exim filter files include an &%if%& command with its own regular expression matching condition. +If the subject string was tainted then any captured substring will also be. .vitem "&$acl_arg1$&, &$acl_arg2$&, etc" Within an acl condition, expansion condition or expansion item @@ -12432,11 +12339,10 @@ authentication, which means this variable could also be visible in all of the ACL's as well. -.vitem &$authenticated_sender$& +.tvar &$authenticated_sender$& .cindex "sender" "authenticated" .cindex "authentication" "sender" .cindex "AUTH" "on MAIL command" -.vindex "&$authenticated_sender$&" When acting as a server, Exim takes note of the AUTH= parameter on an incoming SMTP MAIL command if it believes the sender is sufficiently trusted, as described in section &<>&. Unless the data is the string @@ -12459,9 +12365,10 @@ command that does not succeed. Otherwise it is set to &"0"&. This makes it possible to distinguish between &"did not try to authenticate"& (&$sender_host_authenticated$& is empty and &$authentication_failed$& is set to &"0"&) and &"tried to authenticate but failed"& (&$sender_host_authenticated$& -is empty and &$authentication_failed$& is set to &"1"&). Failure includes any -negative response to an AUTH command, including (for example) an attempt to use -an undefined mechanism. +is empty and &$authentication_failed$& is set to &"1"&). +Failure includes cancellation of a authentication attempt, +and any negative response to an AUTH command, +(including, for example, an attempt to use an undefined mechanism). .vitem &$av_failed$& .cindex "content scanning" "AV scanner failure" @@ -12588,8 +12495,7 @@ the following data from the lookup: the list's domain name, the key that was looked up, the contents of any associated TXT record, and the value from the main A record. See section &<>& for more details. -.vitem &$domain$& -.vindex "&$domain$&" +.tvar &$domain$& When an address is being routed, or delivered on its own, this variable contains the domain. Uppercase letters in the domain are converted into lower case for &$domain$&. @@ -12690,6 +12596,7 @@ There may be other characters following the minor version. This value may be overridden by the &%exim_version%& main config option. .vitem &$header_$&<&'name'&> +.tmark This is not strictly an expansion variable. It is expansion syntax for inserting the message header line with the given name. Note that the name must be terminated by colon or white space, because it may contain a wide variety of @@ -12750,6 +12657,7 @@ allows you, for example, to do things like this: deny hosts = net-lsearch;/some/file message = $host_data .endd + .vitem &$host_lookup_deferred$& .cindex "host name" "lookup, failure of" .vindex "&$host_lookup_deferred$&" @@ -12832,8 +12740,7 @@ This variable contains the system load average, multiplied by 1000 so that it is an integer. For example, if the load average is 0.21, the value of the variable is 210. The value is recomputed every time the variable is referenced. -.vitem &$local_part$& -.vindex "&$local_part$&" +.tvar &$local_part$& When an address is being routed, or delivered on its own, this variable contains the local part. When a number of addresses are being delivered together (for example, multiple RCPT commands in an SMTP @@ -13008,11 +12915,10 @@ This variable is set at the start of a delivery attempt to contain the number of seconds since the message was received. It does not change during a single delivery attempt. -.vitem &$message_body$& +.tvar &$message_body$& .cindex "body of message" "expansion variable" .cindex "message body" "in expansion" .cindex "binary zero" "in message body" -.vindex "&$message_body$&" .oindex "&%message_body_visible%&" This variable contains the initial portion of a message's body while it is being delivered, and is intended mainly for use in filter files. The maximum @@ -13025,10 +12931,9 @@ easier to search for phrases that might be split over a line break. However, this can be disabled by setting &%message_body_newlines%& to be true. Binary zeros are always converted into spaces. -.vitem &$message_body_end$& +.tvar &$message_body_end$& .cindex "body of message" "expansion variable" .cindex "message body" "in expansion" -.vindex "&$message_body_end$&" This variable contains the final portion of a message's body while it is being delivered. The format and maximum size are as for &$message_body$&. @@ -13055,15 +12960,13 @@ received. &*Note*&: This is &'not'& the contents of the &'Message-ID:'& header line; it is the local id that Exim assigns to the message, for example: &`1BXTIK-0001yO-VA`&. -.vitem &$message_headers$& -.vindex &$message_headers$& +.tvar &$message_headers$& This variable contains a concatenation of all the header lines when a message is being processed, except for lines added by routers or transports. The header lines are separated by newline characters. Their contents are decoded in the same way as a header line that is inserted by &%bheader%&. -.vitem &$message_headers_raw$& -.vindex &$message_headers_raw$& +.tvar &$message_headers_raw$& This variable is like &$message_headers$& except that no processing of the contents of header lines is done. @@ -13140,9 +13043,8 @@ details, see section &<>&. These variables are counters that can be incremented by means of the &%add%& command in filter files. -.vitem &$original_domain$& +.tvar &$original_domain$& .vindex "&$domain$&" -.vindex "&$original_domain$&" When a top-level address is being processed for delivery, this contains the same value as &$domain$&. However, if a &"child"& address (for example, generated by an alias, forward, or filter file) is being processed, this @@ -13155,9 +13057,8 @@ If a new address is created by means of a &%deliver%& command in a system filter, it is set up with an artificial &"parent"& address. This has the local part &'system-filter'& and the default qualify domain. -.vitem &$original_local_part$& +.tvar &$original_local_part$& .vindex "&$local_part$&" -.vindex "&$original_local_part$&" When a top-level address is being processed for delivery, this contains the same value as &$local_part$&, unless a prefix or suffix was removed from the local part, because &$original_local_part$& always contains the full local @@ -13195,13 +13096,11 @@ messages received via the command line, this is the uid of the sending user. For messages received by SMTP over TCP/IP, this is normally the uid of the Exim user. -.vitem &$parent_domain$& -.vindex "&$parent_domain$&" +.tvar &$parent_domain$& This variable is similar to &$original_domain$& (see above), except that it refers to the immediately preceding parent address. -.vitem &$parent_local_part$& -.vindex "&$parent_local_part$&" +.tvar &$parent_local_part$& This variable is similar to &$original_local_part$& (see above), except that it refers to the immediately preceding parent address. @@ -13220,6 +13119,9 @@ This is not an expansion variable, but is mentioned here because the string (described under &%transport_filter%& in chapter &<>&). It cannot be used in general expansion strings, and provokes an &"unknown variable"& error if encountered. +&*Note*&: This value permits data supplied by a potential attacker to +be used in the command for a &(pipe)& transport. +Such configurations should be carefully assessed for security vulnerbilities. .vitem &$primary_hostname$& .vindex "&$primary_hostname$&" @@ -13309,8 +13211,7 @@ including the one added by Exim (so its value is always greater than zero). It is available in the DATA ACL, the non-SMTP ACL, and while routing and delivering. -.vitem &$received_for$& -.vindex "&$received_for$&" +.tvar &$received_for$& If there is only a single recipient address in an incoming message, this variable contains that address when the &'Received:'& header line is being built. The value is copied after recipient rewriting has happened, but before @@ -13402,8 +13303,7 @@ MAIL). The main use of this variable is expected to be to distinguish between rejections of MAIL and rejections of RCPT. -.vitem &$recipients$& -.vindex "&$recipients$&" +.tvar &$recipients$& This variable contains a list of envelope recipients for a message. A comma and a space separate the addresses in the replacement text. However, the variable is not generally available, to prevent exposure of Bcc recipients in @@ -13440,10 +13340,10 @@ This variable is set to contain the matching regular expression after a When a &%regex%& or &%mime_regex%& ACL condition succeeds, these variables contain the captured substrings identified by the regular expression. +If the subject string was tainted then so will any captured substring. -.vitem &$reply_address$& -.vindex "&$reply_address$&" +.tvar &$reply_address$& When a message is being processed, this variable contains the contents of the &'Reply-To:'& header line if one exists and it is not empty, or otherwise the contents of the &'From:'& header line. Apart from the removal of leading @@ -13492,8 +13392,7 @@ One of its values causes the address to be passed to another router. When this happens, &$self_hostname$& is set to the name of the local host that the original router encountered. In other circumstances its contents are null. -.vitem &$sender_address$& -.vindex "&$sender_address$&" +.tvar &$sender_address$& When a message is being processed, this variable contains the sender's address that was received in the message's envelope. The case of letters in the address is retained, in both the local part and the domain. For bounce messages, the @@ -13508,12 +13407,10 @@ distinguish it from data from a recipient address. The value does not persist after the end of the current ACL statement. If you want to preserve it for longer, you can save it in an ACL variable. -.vitem &$sender_address_domain$& -.vindex "&$sender_address_domain$&" +.tvar &$sender_address_domain$& The domain portion of &$sender_address$&. -.vitem &$sender_address_local_part$& -.vindex "&$sender_address_local_part$&" +.tvar &$sender_address_local_part$& The local part portion of &$sender_address$&. .vitem &$sender_data$& @@ -13551,8 +13448,7 @@ This boolean variable is true if a successful HELO verification was .cindex "DNS" "DNSSEC" done using DNS information the resolver library stated was authenticated data. -.vitem &$sender_helo_name$& -.vindex "&$sender_helo_name$&" +.tvar &$sender_helo_name$& When a message is received from a remote host that has issued a HELO or EHLO command, the argument of that command is placed in this variable. It is also set if HELO or EHLO is used when a message is received using SMTP locally via @@ -13609,8 +13505,7 @@ all EDNS0 options, then this will have no effect. OpenBSD's asr resolver is known to currently ignore EDNS0, documented in CAVEATS of asr_run(3). -.vitem &$sender_host_name$& -.vindex "&$sender_host_name$&" +.tvar &$sender_host_name$& When a message is received from a remote host, this variable contains the host's name as obtained by looking up its IP address. For messages received by other means, this variable is empty. @@ -13728,8 +13623,7 @@ host name, as specified by the &%smtp_active_hostname%& option. The value of &$smtp_active_hostname$& is saved with any message that is received, so its value can be consulted during routing and delivery. -.vitem &$smtp_command$& -.vindex "&$smtp_command$&" +.tvar &$smtp_command$& During the processing of an incoming SMTP command, this variable contains the entire command. This makes it possible to distinguish between HELO and EHLO in the HELO ACL, and also to distinguish between commands such as these: @@ -13742,9 +13636,8 @@ command, the address in &$smtp_command$& is the original address before any rewriting, whereas the values in &$local_part$& and &$domain$& are taken from the address after SMTP-time rewriting. -.vitem &$smtp_command_argument$& +.tvar &$smtp_command_argument$& .cindex "SMTP" "command, argument for" -.vindex "&$smtp_command_argument$&" While an ACL is running to check an SMTP command, this variable contains the argument, that is, the text that follows the command name, with leading white space removed. Following the introduction of &$smtp_command$&, this variable is @@ -13985,8 +13878,7 @@ which is not the leaf. Observability for TLS session resumption. See &<>& for details. -.vitem &$tls_in_sni$& -.vindex "&$tls_in_sni$&" +.tvar &$tls_in_sni$& .vindex "&$tls_sni$&" .cindex "TLS" "Server Name Indication" .cindex "TLS" SNI @@ -14659,6 +14551,7 @@ listed in more than one group. .row &%log_timezone%& "add timezone to log lines" .row &%message_logs%& "create per-message logs" .row &%preserve_message_logs%& "after message completion" +.row &%panic_coredump%& "request coredump on fatal errors" .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" @@ -14831,6 +14724,7 @@ listed in more than one group. .row &%gnutls_compat_mode%& "use GnuTLS compatibility mode" .row &%gnutls_allow_auto_pkcs11%& "allow GnuTLS to autoload PKCS11 modules" .row &%hosts_require_alpn%& "mandatory ALPN" +.row &%hosts_require_helo%& "mandatory HELO/EHLO" .row &%openssl_options%& "adjust OpenSSL compatibility options" .row &%tls_advertise_hosts%& "advertise TLS to these hosts" .row &%tls_alpn%& "acceptable protocol names" @@ -16295,9 +16189,12 @@ case. That is why the default tries a DNS lookup first. .cindex "host" "rejecting connections from" If this option is set, incoming SMTP calls from the hosts listed are rejected as soon as the connection is made. -This option is obsolete, and retained only for backward compatibility, because +This option is mostly obsolete, retained for backward compatibility because nowadays the ACL specified by &%acl_smtp_connect%& can also reject incoming -connections immediately. +connections immediately +.new +(except for tls-on-connect connections). +.wen The ability to give an immediate rejection (either by this option or using an ACL) is provided for use in unusual cases. Many hosts will just try again, @@ -16318,7 +16215,10 @@ local processes, you must create a host list with an empty item. For example: .code hosts_connection_nolog = : .endd -If the &%smtp_connection%& log selector is not set, this option has no effect. +.new +The hosts affected by this option also do not log "no MAIL in SMTP connection" +lines, as may commonly be produced by a monitoring system. +.wen .option hosts_require_alpn main "host list&!!" unset @@ -16334,6 +16234,12 @@ See also the &%tls_alpn%& option. managed by this option, and should be done separately. +.option hosts_require_helo main "host list&!!" * +.cindex "HELO/EHLO" requiring +Exim will require an accepted HELO or EHLO command from a host matching +this list, before accepting a MAIL command. + + .option hosts_proxy main "host list&!!" unset .cindex proxy "proxy protocol" This option enables use of Proxy Protocol proxies for incoming @@ -16988,6 +16894,19 @@ to be used in conjunction with &(oracle)& lookups (see section &<>&). The option is available only if Exim has been built with Oracle support. +.new +.option panic_coredump main boolean false +This option is rarely needed but can help for some debugging investigations. +If set, when an internal error is detected by Exim which is sufficient +to terminate the process +(all such are logged in the paniclog) +then a coredump is requested. + +Note that most systems require additional administrative configuration +to permit write a core file for a setuid program, which is Exim's +common installed configuration. +.wen + .option percent_hack_domains main "domain list&!!" unset .cindex "&""percent hack""&" .cindex "source routing" "in email address" @@ -17062,9 +16981,9 @@ not count as protocol errors (see &%smtp_max_synprot_errors%&). .option pipelining_connect_advertise_hosts main "host list&!!" * .cindex "pipelining" "early connection" -.cindex "pipelining" PIPE_CONNECT -.cindex "ESMTP extensions" PIPE_CONNECT -If Exim is built with the SUPPORT_PIPE_CONNECT build option +.cindex "pipelining" PIPECONNECT +.cindex "ESMTP extensions" PIPECONNECT +If Exim is built without the DISABLE_PIPE_CONNECT build option this option controls which hosts the facility is advertised to and from which pipeline early-connection (before MAIL) SMTP commands are acceptable. @@ -17072,7 +16991,11 @@ When used, the pipelining saves on roundtrip times. See also the &%hosts_pipe_connect%& smtp transport option. -The SMTP service extension keyword advertised is &"PIPE_CONNECT"&. +The SMTP service extension keyword advertised is &"PIPECONNECT"&; +it permits the client to pipeline +TCP connection and hello command (inclear phase), +or TLS-establishment and hello command (encrypted phase), +on later connections to the same host. .option prdr_enable main boolean false @@ -17194,7 +17117,7 @@ domains that do not match are processed. All other deliveries wait until the next queue run. See also &%hold_domains%& and &%queue_smtp_domains%&. -.option queue_fast_ramp main boolean false +.option queue_fast_ramp main boolean true .cindex "queue runner" "two phase" .cindex "queue" "double scanning" If set to true, two-phase queue runs, initiated using &%-qq%& on the @@ -17438,7 +17361,7 @@ initial set of recipients. The remote server should then re-send the message for the remaining recipients at a later time. -.option remote_max_parallel main integer 2 +.option remote_max_parallel main integer 4 .cindex "delivery" "parallelism for remote" This option controls parallel delivery of one message to a number of remote hosts. If the value is less than 2, parallel delivery is disabled, and Exim @@ -18487,7 +18410,6 @@ of the later IKE values, which led into RFC7919 providing new fixed constants At this point, all of the "ike" values should be considered obsolete; they are still in Exim to avoid breaking unusual configurations, but are candidates for removal the next time we have backwards-incompatible changes. -.new Two of them in particular (&`ike1`& and &`ike22`&) are called out by RFC 8247 as MUST NOT use for IPSEC, and two more (&`ike23`& and &`ike24`&) as SHOULD NOT. @@ -18495,7 +18417,6 @@ Because of this, Exim regards them as deprecated; if either of the first pair are used, warnings will be logged in the paniclog, and if any are used then warnings will be logged in the mainlog. All four will be removed in a future Exim release. -.wen The TLS protocol does not negotiate an acceptable size for this; clients tend to hard-drop connections if what is offered by the server is unacceptable, @@ -18973,6 +18894,7 @@ than trying to read &_/etc/passwd_& directly. This means that other methods of holding password data (such as NIS) are supported. If the local part is a local user, .cindex "tainted data" "de-tainting" +.cindex "de-tainting" "using router check_local_user option" &$local_part_data$& is set to an untainted version of the local part and &$home$& is set from the password data. The latter can be tested in other preconditions that are evaluated after this one (the order of evaluation is @@ -22806,9 +22728,10 @@ an ideal name for this feature here, but as it was already implemented for the The expansion variables &$host$& and &$host_address$& are available when the transport is a remote one. They contain the name and IP address of the host to which the message is being sent. For example: +. used to have $sender_address in this cmdline, but it's tainted .code transport_filter = /some/directory/transport-filter.pl \ - $host $host_address $sender_address $pipe_addresses + $host $host_address $pipe_addresses .endd Two problems arise if you want to use more complicated expansion items to @@ -23244,6 +23167,7 @@ The value is used for checking instead of a home directory; checking is done in "belowhome" mode. .cindex "tainted data" "de-tainting" +.cindex "de-tainting" "using appendfile create_file option" If "belowhome" checking is used, the file or directory path becomes de-tainted. @@ -24679,6 +24603,9 @@ This list is a compromise for maximum compatibility with other MTAs. Note that the &%environment%& option can be used to add additional variables to this environment. The environment for the &(pipe)& transport is not subject to the &%add_environment%& and &%keep_environment%& main config options. +&*Note*&: Using enviroment variables loses track of tainted data. +Writers of &(pipe)& transport commands should be wary of data supplied +by potential attackers. .display &`DOMAIN `& the domain of the address &`HOME `& the home directory, if set @@ -24770,6 +24697,9 @@ the &%path%& option below). The command is split up into separate arguments by Exim, and each argument is separately expanded, as described in section &<>& above. +.cindex "tainted data" +No part of the resulting command may be tainted. + .option environment pipe string&!! unset .cindex "&(pipe)& transport" "environment for command" @@ -25085,12 +25015,15 @@ use a shell to run pipe commands. .cindex "Cyrus" The next example shows a transport and a router for a system where local deliveries are handled by the Cyrus IMAP server. +. Used to have R: local_part_suffix = .* + T: -m $local_part_suffix_v +. but that suffix is tainted so cannot be used in a command arg +. Really, you'd want to use a lookup for acceptable suffixes to do real detainting .code # transport local_delivery_cyrus: driver = pipe command = /usr/cyrus/bin/deliver \ - -m ${substr_1:$local_part_suffix} -- $local_part + -- $local_part_data user = cyrus group = mail return_output @@ -25102,7 +25035,6 @@ local_delivery_cyrus: local_user_cyrus: driver = accept check_local_user - local_part_suffix = .* transport = local_delivery_cyrus .endd Note the unsetting of &%message_prefix%& and &%message_suffix%&, and the use of @@ -25468,12 +25400,43 @@ servers or different local IP addresses. For example, if you want the string that is used for &%helo_data%& to be obtained by a DNS lookup of the outgoing interface address, you could use this: .code -helo_data = ${lookup dnsdb{ptr=$sending_ip_address}{$value}\ +helo_data = ${lookup dnsdb{ptr=$sending_ip_address} \ + {${listextract{1}{<\n $value}}} \ {$primary_hostname}} .endd The use of &%helo_data%& applies both to sending messages and when doing callouts. +.option host_name_extract smtp "string list&!!" "see below" +.cindex "load balancer" "hosts behind" +.cindex TLS resumption +Some mail-accepting sites +(notably Microsoft) +operate many servers behind a network load-balancer. When this is done, +with separated TLS session caches, TLS session resuption becomes problematic. +It will only succeed when the same server happens to be selected by the +load-balancer, matching the session stored in the client's cache. + +Exim can pull out a server name, if there is one, from the response to the +client's SMTP EHLO command. +The default value of this option: +.code + ${if and { {match {$host} {.outlook.com\$}} \ + {match {$item} {\N^250-([\w.]+)\s\N}} \ + } {$1}} +.endd +suffices for one known case. +During the expansion of this option the &$item$& variable will have the +server's EHLO response. +The result of the option expansion is included in the key used to store and +retrieve the TLS session, for session resumption. + +Operators of high-load sites may wish to evaluate their logs for indications +of other destination sites operating load-balancers, and develop a suitable +expression for this option. +The smtp:ehlo event and the &$tls_out_resumption$& variable +will be useful for such work. + .option hosts smtp "string list&!!" unset Hosts are associated with an address by a router such as &(dnslookup)&, which finds the hosts by looking up the address domain in the DNS, or by @@ -25527,7 +25490,7 @@ that matches this list, even if the server host advertises PIPELINING support. .option hosts_pipe_connect smtp "host list&!!" unset .cindex "pipelining" "early connection" -.cindex "pipelining" PIPE_CONNECT +.cindex "pipelining" PIPECONNECT If Exim is built with the SUPPORT_PIPE_CONNECT build option this option controls which to hosts the facility watched for and recorded, and used for subsequent connections. @@ -25541,7 +25504,8 @@ so combines well with TCP Fast Open. See also the &%pipelining_connect_advertise_hosts%& main option. Note: -When the facility is used, the transport &%helo_data%& option +When the facility is used, if the transport &%interface%& option is unset +the &%helo_data%& option will be expanded before the &$sending_ip_address$& variable is filled in. A check is made for the use of that variable, without the @@ -25646,12 +25610,18 @@ hard failure if required. See also &%hosts_try_auth%&, and chapter &<>& for details of authentication. -.option hosts_request_ocsp smtp "host list&!!" * +.option hosts_request_ocsp smtp "host list&!!" "see below" .cindex "TLS" "requiring for certain servers" Exim will request a Certificate Status on a TLS session for any host that matches this list. &%tls_verify_certificates%& should also be set for the transport. +.new +The default is &"**"& if DANE is not in use for the connection, +or if DANE-TA us used. +It is empty if DANE-EE is used. +.wen + .option hosts_require_alpn smtp "host list&!!" unset .cindex ALPN "require negotiation in client" .cindex TLS ALPN @@ -25674,11 +25644,6 @@ There will be no fallback to in-clear communication. See the &%dnssec_request_domains%& router and transport options. See section &<>&. -.option hosts_require_helo smtp "host list&!!" * -.cindex "HELO/EHLO" requiring -Exim will require an accepted HELO or EHLO command from a host matching -this list, before accepting a MAIL command. - .option hosts_require_ocsp smtp "host list&!!" unset .cindex "TLS" "requiring for certain servers" Exim will request, and check for a valid Certificate Status being given, on a @@ -26126,7 +26091,7 @@ If both this option and &%tls_try_verify_hosts%& are unset operation is as if this option selected all hosts. &*Warning*&: Including a host in &%tls_verify_hosts%& does not require that connections use TLS. -Fallback to in-clear communication will be done unless restricted by +Fallback to in-clear communication will be done unless restricted by the &%hosts_require_tls%& option. .option utf8_downconvert smtp integer&!! -1 @@ -26302,7 +26267,7 @@ message's processing. .vindex "&$sender_address$&" At the start of an ACL for MAIL, the sender address may have been rewritten -by a special SMTP-time rewrite rule (see section &<>&), but no +by a special SMTP-time rewrite rule (see section &<>&), but no ordinary rewrite rules have yet been applied. If, however, the sender address is verified in the ACL, it is rewritten before verification, and remains rewritten thereafter. The subsequent value of &$sender_address$& is the @@ -26509,7 +26474,7 @@ entry written to the panic log. -.section "Rewriting flags" "SECID153" +.subsection "Rewriting flags" "SSECID153" There are three different kinds of flag that may appear on rewriting rules: .ilist @@ -26526,11 +26491,11 @@ E, F, T, and S are not permitted. -.section "Flags specifying which headers and envelope addresses to rewrite" &&& - "SECID154" -.cindex "rewriting" "flags" +.subsection "Flags specifying which headers and envelope addresses to rewrite" &&& + "SSECID154" +.cindex rewriting flags If none of the following flag letters, nor the &"S"& flag (see section -&<>&) are present, a main rewriting rule applies to all headers +&<>&) are present, a main rewriting rule applies to all headers and to both the sender and recipient fields of the envelope, whereas a transport-time rewriting rule just applies to all headers. Otherwise, the rewriting rule is skipped unless the relevant addresses are being processed. @@ -26554,10 +26519,10 @@ You should be particularly careful about rewriting &'Sender:'& headers, and restrict this to special known cases in your own domains. -.section "The SMTP-time rewriting flag" "SECTrewriteS" -.cindex "SMTP" "rewriting malformed addresses" -.cindex "RCPT" "rewriting argument of" -.cindex "MAIL" "rewriting argument of" +.subsection "The SMTP-time rewriting flag" SSECTrewriteS +.cindex SMTP "rewriting malformed addresses" +.cindex RCPT "rewriting argument of" +.cindex MAIL "rewriting argument of" The rewrite flag &"S"& specifies a rewrite of incoming envelope addresses at SMTP time, as soon as an address is received in a MAIL or RCPT command, and before any other processing; even before syntax checking. The pattern is @@ -26574,7 +26539,7 @@ expansion of the replacement string. The result of rewriting replaces the original address in the MAIL or RCPT command. -.section "Flags controlling the rewriting process" "SECID155" +.subsection "Flags controlling the rewriting process" SSECID155 There are four flags which control the way the rewriting process works. These take effect only when a rule is invoked, that is, when the address is of the correct type (matches the flags) and matches the pattern: @@ -27254,7 +27219,7 @@ it is enforced. .cindex "ESMTP extensions" AUTH Very briefly, the way SMTP authentication works is as follows: -.ilist +.olist The server advertises a number of authentication &'mechanisms'& in response to the client's EHLO command. .next @@ -27610,7 +27575,18 @@ no successful authentication. Successful authentication sets up information used by the &%authresults%& expansion item. - +.new +.cindex authentication "failure event, server" +If an authenticator is run and does not succeed, +an event (see &<>&) of type "auth:fail" is raised. +While the event is being processed the variables +&$sender_host_authenticated$& (with the authenticator name) +and &$authenticated_fail_id$& (as set by the authenticator &%server_set_id%& option) +will be valid. +If the event is serviced and a string is returned then the string will be logged +instead of the default log line. +See <> for details on events. +.wen .section "Testing server authentication" "SECID169" @@ -27688,6 +27664,19 @@ If the result of the authentication attempt is a temporary error or a timeout, Exim abandons trying to send the message to the host for the moment. It will try again later. If there are any backup hosts available, they are tried in the usual way. + +.new +.next +.cindex authentication "failure event, client" +If the response to authentication is a permanent error (5&'xx'& code), +an event (see &<>&) of type "auth:fail" is raised. +While the event is being processed the variable +&$sender_host_authenticated$& (with the authenticator name) +will be valid. +If the event is serviced and a string is returned then the string will be logged. +See <> for details on events. +.wen + .next If the response to authentication is a permanent error (5&'xx'& code), Exim carries on searching the list of authenticators and tries another one if @@ -29422,7 +29411,7 @@ For outgoing SMTP deliveries, &$tls_out_cipher$& is used and logged (again depending on the &%tls_cipher%& log selector). -.section "Requesting and verifying client certificates" "SECID183" +.subsection "Requesting and verifying client certificates" .cindex "certificate" "verification of client" .cindex "TLS" "client certificate verification" If you want an Exim server to request a certificate when negotiating a TLS @@ -29475,86 +29464,7 @@ Because it is often a long text string, it is not included in the log line or certificate is supplied, &$tls_in_peerdn$& is empty. -.section "Revoked certificates" "SECID184" -.cindex "TLS" "revoked certificates" -.cindex "revocation list" -.cindex "certificate" "revocation list" -.cindex "OCSP" "stapling" -Certificate issuing authorities issue Certificate Revocation Lists (CRLs) when -certificates are revoked. If you have such a list, you can pass it to an Exim -server using the global option called &%tls_crl%& and to an Exim client using -an identically named option for the &(smtp)& transport. In each case, the value -of the option is expanded and must then be the name of a file that contains a -CRL in PEM format. -The downside is that clients have to periodically re-download a potentially huge -file from every certificate authority they know of. - -The way with most moving parts at query time is Online Certificate -Status Protocol (OCSP), where the client verifies the certificate -against an OCSP server run by the CA. This lets the CA track all -usage of the certs. It requires running software with access to the -private key of the CA, to sign the responses to the OCSP queries. OCSP -is based on HTTP and can be proxied accordingly. - -The only widespread OCSP server implementation (known to this writer) -comes as part of OpenSSL and aborts on an invalid request, such as -connecting to the port and then disconnecting. This requires -re-entering the passphrase each time some random client does this. - -The third way is OCSP Stapling; in this, the server using a certificate -issued by the CA periodically requests an OCSP proof of validity from -the OCSP server, then serves it up inline as part of the TLS -negotiation. This approach adds no extra round trips, does not let the -CA track users, scales well with number of certs issued by the CA and is -resilient to temporary OCSP server failures, as long as the server -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, -or with GnuTLS earlier than version 3.3.16 / 3.4.8 -support for OCSP stapling is included. - -There is a global option called &%tls_ocsp_file%&. -The file specified therein is expected to be in DER format, and contain -an OCSP proof. Exim will serve it as part of the TLS handshake. This -option will be re-expanded for SNI, if the &%tls_certificate%& option -contains &`tls_in_sni`&, as per other TLS options. - -Exim does not at this time implement any support for fetching a new OCSP -proof. The burden is on the administrator to handle this, outside of -Exim. The file specified should be replaced atomically, so that the -contents are always valid. Exim will expand the &%tls_ocsp_file%& option -on each connection, so a new file will be handled transparently on the -next connection. - -When built with OpenSSL Exim will check for a valid next update timestamp -in the OCSP proof; if not present, or if the proof has expired, it will be -ignored. - -For the client to be able to verify the stapled OCSP the server must -also supply, in its stapled information, any intermediate -certificates for the chain leading to the OCSP proof from the signer -of the server certificate. There may be zero or one such. These -intermediate certificates should be added to the server OCSP stapling -file named by &%tls_ocsp_file%&. - -Note that the proof only covers the terminal server certificate, -not any of the chain from CA to it. - -There is no current way to staple a proof for a client certificate. - -.code - A helper script "ocsp_fetch.pl" for fetching a proof from a CA - OCSP server is supplied. The server URL may be included in the - server certificate, if the CA is helpful. - - One failure mode seen was the OCSP Signer cert expiring before the end - of validity of the OCSP proof. The checking done by Exim/OpenSSL - noted this as invalid overall, but the re-fetch script did not. -.endd - - -.section "Caching of static server configuration items" "SECTserverTLScache" +.subsection "Caching of static server configuration items" "SSECTserverTLScache" .cindex certificate caching .cindex privatekey caching .cindex crl caching @@ -29728,7 +29638,7 @@ outgoing connection. -.section "Caching of static client configuration items" "SECTclientTLScache" +.subsection "Caching of static client configuration items" SECTclientTLScache .cindex certificate caching .cindex privatekey caching .cindex crl caching @@ -29818,7 +29728,7 @@ only point of caution. The &$tls_out_sni$& variable will be set to this string for the lifetime of the client connection (including during authentication). If DANE validated the connection attempt then the value of the &%tls_sni%& option -is forced to the domain part of the recipient address. +is forced to the name of the destination host, after any MX- or CNAME-following. Except during SMTP client sessions, if &$tls_in_sni$& is set then it is a string received from a client. @@ -29860,6 +29770,7 @@ When Exim is built against GnuTLS, SNI support is available as of GnuTLS 0.5.10. (Its presence predates the current API which Exim uses, so if Exim built, then you have SNI support). +.subsection ALPN .cindex TLS ALPN .cindex ALPN "general information" .cindex TLS "Application Layer Protocol Names" @@ -29870,7 +29781,7 @@ connection. The client for the connection proposes a set of protocol names, and the server responds with a selected one. It is not, as of 2021, commonly used for SMTP connections. -However, to guard against misirected or malicious use of web clients +However, to guard against misdirected or malicious use of web clients (which often do use ALPN) against MTA ports, Exim by default check that there is no incompatible ALPN specified by a client for a TLS connection. If there is, the connection is rejected. @@ -29880,7 +29791,7 @@ The behaviour of both client and server can be configured using the options &%tls_alpn%& and &%hosts_require_alpn%&. There are no variables providing observability. Some feature-specific logging may appear on denied connections, but this -depends on the behavious of the peer +depends on the behaviour of the peer (not all peers can send a feature-specific TLS Alert). This feature is available when Exim is built with @@ -29959,7 +29870,7 @@ Ivan is the author of the popular TLS testing tools at &url(https://www.ssllabs.com/). -.section "Certificate chains" "SECID186" +.subsection "Certificate chains" SECID186 A file named by &%tls_certificate%& may contain more than one certificate. This is useful in the case where the certificate that is being sent is validated by an intermediate certificate which the other end does @@ -29980,7 +29891,7 @@ diagnostics in such a case can be frustratingly vague. -.section "Self-signed certificates" "SECID187" +.subsection "Self-signed certificates" SECID187 .cindex "certificate" "self-signed" You can create a self-signed certificate using the &'req'& command provided with OpenSSL, like this: @@ -30029,6 +29940,94 @@ For information on creating self-signed CA certificates and using them to sign user certificates, see the &'General implementation overview'& chapter of the Open-source PKI book, available online at &url(https://sourceforge.net/projects/ospkibook/). + + +.subsection "Revoked certificates" +.cindex "TLS" "revoked certificates" +.cindex "revocation list" +.cindex "certificate" "revocation list" +.cindex "OCSP" "stapling" +There are three ways for a certificate to be made unusable +before its expiry. + +.ilist +Certificate issuing authorities issue Certificate Revocation Lists (CRLs) when +certificates are revoked. If you have such a list, you can pass it to an Exim +server using the global option called &%tls_crl%& and to an Exim client using +an identically named option for the &(smtp)& transport. In each case, the value +of the option is expanded and must then be the name of a file that contains a +CRL in PEM format. +The downside is that clients have to periodically re-download a potentially huge +file from every certificate authority they know of. + +.next +The way with most moving parts at query time is Online Certificate +Status Protocol (OCSP), where the client verifies the certificate +against an OCSP server run by the CA. This lets the CA track all +usage of the certs. It requires running software with access to the +private key of the CA, to sign the responses to the OCSP queries. OCSP +is based on HTTP and can be proxied accordingly. + +The only widespread OCSP server implementation (known to this writer) +comes as part of OpenSSL and aborts on an invalid request, such as +connecting to the port and then disconnecting. This requires +re-entering the passphrase each time some random client does this. + +.next +The third way is OCSP Stapling; in this, the server using a certificate +issued by the CA periodically requests an OCSP proof of validity from +the OCSP server, then serves it up inline as part of the TLS +negotiation. This approach adds no extra round trips, does not let the +CA track users, scales well with number of certs issued by the CA and is +resilient to temporary OCSP server failures, as long as the server +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, +or with GnuTLS earlier than version 3.3.16 / 3.4.8 +support for OCSP stapling is included. + +There is a global option called &%tls_ocsp_file%&. +The file specified therein is expected to be in DER format, and contain +an OCSP proof. Exim will serve it as part of the TLS handshake. This +option will be re-expanded for SNI, if the &%tls_certificate%& option +contains &`tls_in_sni`&, as per other TLS options. + +Exim does not at this time implement any support for fetching a new OCSP +proof. The burden is on the administrator to handle this, outside of +Exim. The file specified should be replaced atomically, so that the +contents are always valid. Exim will expand the &%tls_ocsp_file%& option +on each connection, so a new file will be handled transparently on the +next connection. + +When built with OpenSSL Exim will check for a valid next update timestamp +in the OCSP proof; if not present, or if the proof has expired, it will be +ignored. + +For the client to be able to verify the stapled OCSP the server must +also supply, in its stapled information, any intermediate +certificates for the chain leading to the OCSP proof from the signer +of the server certificate. There may be zero or one such. These +intermediate certificates should be added to the server OCSP stapling +file named by &%tls_ocsp_file%&. + +Note that the proof only covers the terminal server certificate, +not any of the chain from CA to it. + +There is no current way to staple a proof for a client certificate. + +.code + A helper script "ocsp_fetch.pl" for fetching a proof from a CA + OCSP server is supplied. The server URL may be included in the + server certificate, if the CA is helpful. + + One failure mode seen was the OCSP Signer cert expiring before the end + of validity of the OCSP proof. The checking done by Exim/OpenSSL + noted this as invalid overall, but the re-fetch script did not. +.endd +.endlist + + .ecindex IIDencsmtp1 .ecindex IIDencsmtp2 @@ -30146,18 +30145,24 @@ DANE scales better than having to maintain (and communicate via side-channel) co for every possible target server. It also scales (slightly) better than having to maintain on an SMTP client a copy of the standard CAs bundle. It also means not having to pay a CA for certificates. -DANE requires a server operator to do three things: 1) run DNSSEC. This provides assurance to clients +DANE requires a server operator to do three things: +.olist +Run DNSSEC. This provides assurance to clients that DNS lookups they do for the server have not been tampered with. The domain MX record applying to this server, its A record, its TLSA record and any associated CNAME records must all be covered by DNSSEC. -2) add TLSA DNS records. These say what the server certificate for a TLS connection should be. -3) offer a server certificate, or certificate chain, in TLS connections which is is anchored by one of the TLSA records. +.next +Add TLSA DNS records. These say what the server certificate for a TLS connection should be. +.next +Offer a server certificate, or certificate chain, in TLS connections which is is anchored by one of the TLSA records. +.endlist There are no changes to Exim specific to server-side operation of DANE. Support for client-side operation of DANE can be included at compile time by defining SUPPORT_DANE=yes in &_Local/Makefile_&. If it has been included, the macro "_HAVE_DANE" will be defined. +.subsection "DNS records" A TLSA record consist of 4 fields, the "Certificate Usage", the "Selector", the "Matching type", and the "Certificate Association Data". For a detailed description of the TLSA record see @@ -30238,6 +30243,7 @@ libraries. This means no MD5 and no SHA-1. SHA2-256 is the minimum for reliable interoperability (and probably the maximum too, in 2018). +.subsection "Interaction with OCSP" The use of OCSP-stapling should be considered, allowing for fast revocation of certificates (which would otherwise be limited by the DNS TTL on the TLSA records). However, this is likely to only be usable with DANE-TA. NOTE: the default of requesting OCSP for all hosts is modified iff DANE is in use, to: @@ -30258,6 +30264,7 @@ This modification of hosts_request_ocsp is only done if it has the default value those who use &%hosts_require_ocsp%&, should consider the interaction with DANE in their OCSP settings. +.subsection "Client configuration" For client-side DANE there are three new smtp transport options, &%hosts_try_dane%&, &%hosts_require_dane%& and &%dane_require_tls_ciphers%&. The &"require"& variant will result in failure if the target host is not @@ -30296,6 +30303,7 @@ verification evaluation is wanted, the above variables should be set appropriate The router and transport option &%dnssec_request_domains%& must not be set to &"never"&, and &%dnssec_require_domains%& is ignored. +.subsection Observability If verification was successful using DANE then the "CV" item in the delivery log line will show as "CV=dane". There is a new variable &$tls_out_dane$& which will have "yes" if @@ -30311,11 +30319,13 @@ required. This is intended to support TLS-reporting as defined in The &$event_data$& will be one of the Result Types defined in Section 4.3 of that document. +.subsection General Under GnuTLS, DANE is only supported from version 3.0.0 onwards. DANE is specified in published RFCs and decouples certificate authority trust selection from a "race to the bottom" of "you must trust everything for mail -to get through". There is an alternative technology called MTA-STS, which +to get through". +There is an alternative technology called MTA-STS, which instead publishes MX trust anchor information on an HTTPS website. At the time this text was last updated, MTA-STS was still a draft, not yet an RFC. Exim has no support for MTA-STS as a client, but Exim mail server operators @@ -30429,7 +30439,7 @@ trying to deliver the message. It is therefore recommended that you do as much testing as possible at RCPT time. -.section "The non-SMTP ACLs" "SECID190" +.subsection "The non-SMTP ACLs" SECID190 .cindex "non-SMTP messages" "ACLs for" The non-SMTP ACLs apply to all non-interactive incoming messages, that is, they apply to batched SMTP as well as to non-SMTP messages. (Batched SMTP is not @@ -30463,7 +30473,7 @@ kind of rejection is treated as permanent, because there is no way of sending a temporary error for these kinds of message. -.section "The SMTP connect ACL" "SECID191" +.subsection "The SMTP connect ACL" SECID191 .cindex "SMTP" "connection, ACL for" .oindex &%smtp_banner%& The ACL test specified by &%acl_smtp_connect%& happens at the start of an SMTP @@ -30473,13 +30483,11 @@ accepted by an &%accept%& verb that has a &%message%& modifier, the contents of the message override the banner message that is otherwise specified by the &%smtp_banner%& option. -.new For tls-on-connect connections, the ACL is run after the TLS connection is accepted (however, &%host_reject_connection%& is tested before). -.wen -.section "The EHLO/HELO ACL" "SECID192" +.subsection "The EHLO/HELO ACL" SECID192 .cindex "EHLO" "ACL for" .cindex "HELO" "ACL for" The ACL test specified by &%acl_smtp_helo%& happens when the client issues an @@ -30500,7 +30508,7 @@ affect the EHLO options that are listed on the second and subsequent lines of an EHLO response. -.section "The DATA ACLs" "SECID193" +.subsection "The DATA ACLs" SECID193 .cindex "DATA" "ACLs for" Two ACLs are associated with the DATA command, because it is two-stage command, with two responses being sent to the client. @@ -30539,7 +30547,7 @@ the &%acl_smtp_data_prdr%&, the &%acl_smtp_dkim%& and the &%acl_smtp_mime%& ACLs. -.section "The SMTP DKIM ACL" "SECTDKIMACL" +.subsection "The SMTP DKIM ACL" SECTDKIMACL The &%acl_smtp_dkim%& ACL is available only when Exim is compiled with DKIM support enabled (which is the default). @@ -30552,14 +30560,14 @@ This ACL is evaluated before &%acl_smtp_mime%& and &%acl_smtp_data%&. For details on the operation of DKIM, see section &<>&. -.section "The SMTP MIME ACL" "SECID194" +.subsection "The SMTP MIME ACL" SECID194 The &%acl_smtp_mime%& option is available only when Exim is compiled with the content-scanning extension. For details, see chapter &<>&. This ACL is evaluated after &%acl_smtp_dkim%& but before &%acl_smtp_data%&. -.section "The SMTP PRDR ACL" "SECTPRDRACL" +.subsection "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 @@ -30593,7 +30601,7 @@ This ACL is evaluated after &%acl_smtp_dkim%& but before &%acl_smtp_data%&. If the ACL is not defined, processing completes as if the feature was not requested by the client. -.section "The QUIT ACL" "SECTQUITACL" +.subsection "The QUIT ACL" SECTQUITACL .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 @@ -30620,7 +30628,7 @@ client are given temporary error responses until QUIT is received or the connection is closed. In these special cases, the QUIT ACL does not run. -.section "The not-QUIT ACL" "SECTNOTQUITACL" +.subsection "The not-QUIT ACL" SECTNOTQUITACL .vindex &$acl_smtp_notquit$& The not-QUIT ACL, specified by &%acl_smtp_notquit%&, is run in most cases when an SMTP session ends without sending QUIT. However, when Exim itself is in bad @@ -31596,12 +31604,12 @@ This control turns on debug logging, almost as though Exim had been invoked with &`-d`&, with the output going to a new logfile in the usual logs directory, by default called &'debuglog'&. -.new +Logging set up by the control will be maintained across spool residency. + Options are a slash-separated list. If an option takes an argument, the option name and argument are separated by an equals character. Several options are supported: -.wen .display tag=<&'suffix'&> The filename can be adjusted with thise option. The argument, which may access any variables already defined, @@ -31627,7 +31635,7 @@ pretrigger=<&'size'&> This option specifies a memory buffuer to be used immediate writes to file are done as normal. trigger=<&'reason'&> This option selects cause for the pretrigger buffer - see above) to be copied to file. A reason of $*now* + see above) to be copied to file. A reason of &*now*& take effect immediately; one of &*paniclog*& triggers on a write to the panic log. .endd @@ -32159,7 +32167,7 @@ different variants of this condition to describe briefly here. See sections .cindex "domain" "ACL checking" .cindex "&ACL;" "testing a recipient domain" .vindex "&$domain_data$&" -This condition is relevant only after a RCPT command. It checks that the domain +This condition is relevant only in a RCPT ACL. It checks that the domain of the recipient address is in the domain list. If percent-hack processing is enabled, it is done before this test is done. If the check succeeds with a lookup, the result of the lookup is placed in &$domain_data$& until the next @@ -32227,7 +32235,7 @@ which gives a custom error message for each denied host. .cindex "local part" "ACL checking" .cindex "&ACL;" "testing a local part" .vindex "&$local_part_data$&" -This condition is relevant only after a RCPT command. It checks that the local +This condition is relevant only in a RCPT ACL. It checks that the local part of the recipient address is in the list. If percent-hack processing is enabled, it is done before this test. If the check succeeds with a lookup, the result of the lookup is placed in &$local_part_data$&, which remains set until @@ -32261,7 +32269,7 @@ messages. Details are given in section &<>&. .cindex "&%recipients%& ACL condition" .cindex "recipient" "ACL checking" .cindex "&ACL;" "testing a recipient" -This condition is relevant only after a RCPT command. It checks the entire +This condition is relevant only in a RCPT ACL. It checks the entire recipient address against a list of recipients. .vitem &*regex&~=&~*&<&'list&~of&~regular&~expressions'&> @@ -32272,13 +32280,11 @@ content-scanning extension, and is available only in the DATA, MIME, and non-SMTP ACLs. It causes the incoming message to be scanned for a match with any of the regular expressions. For details, see chapter &<>&. -.new .vitem &*seen&~=&~*&<&'parameters'&> -.cindex "&%sseen%& ACL condition" +.cindex "&%seen%& ACL condition" This condition can be used to test if a situation has been previously met, for example for greylisting. Details are given in section &<>&. -.wen .vitem &*sender_domains&~=&~*&<&'domain&~list'&> .cindex "&%sender_domains%& ACL condition" @@ -32538,11 +32544,11 @@ This is usually the required action when &%dnslists%& is used with &%deny%& (which is the most common usage), because it prevents a DNS failure from blocking mail. However, you can change this behaviour by putting one of the following special items in the list: -.display -&`+include_unknown `& behave as if the item is on the list -&`+exclude_unknown `& behave as if the item is not on the list (default) -&`+defer_unknown `& give a temporary error -.endd +.itable none 0 0 2 25* left 75* left +.irow "+include_unknown" "behave as if the item is on the list" +.irow "+exclude_unknown" "behave as if the item is not on the list (default)" +.irow "+defer_unknown " "give a temporary error" +.endtable .cindex "&`+include_unknown`&" .cindex "&`+exclude_unknown`&" .cindex "&`+defer_unknown`&" @@ -32572,7 +32578,7 @@ or free for small deployments. An overview can be found at -.section "Specifying the IP address for a DNS list lookup" "SECID201" +.subsection "Specifying the IP address for a DNS list lookup" SECID201 .cindex "DNS list" "keyed by explicit IP address" By default, the IP address that is used in a DNS list lookup is the IP address of the calling host. However, you can specify another IP address by listing it @@ -32588,7 +32594,7 @@ MX hosts or nameservers of an email sender address. For an example, see section -.section "DNS lists keyed on domain names" "SECID202" +.subsection "DNS lists keyed on domain names" SECID202 .cindex "DNS list" "keyed by domain name" There are some lists that are keyed on domain names rather than inverted IP addresses (see, e.g., the &'domain based zones'& link at @@ -32618,7 +32624,7 @@ name. The whole condition is true if either of the DNS lookups succeeds. -.section "Multiple explicit keys for a DNS list" "SECTmulkeyfor" +.subsection "Multiple explicit keys for a DNS list" SECTmulkeyfor .cindex "DNS list" "multiple keys for" The syntax described above for looking up explicitly-defined values (either names or IP addresses) in a DNS blacklist is a simplification. After the domain @@ -32685,21 +32691,21 @@ The key that was used for a successful DNS list lookup is put into the variable -.section "Data returned by DNS lists" "SECID203" +.subsection "Data returned by DNS lists" SECID203 .cindex "DNS list" "data returned from" DNS lists are constructed using address records in the DNS. The original RBL just used the address 127.0.0.1 on the right hand side of each record, but the RBL+ list and some other lists use a number of values with different meanings. The values used on the RBL+ list are: -.display -127.1.0.1 RBL -127.1.0.2 DUL -127.1.0.3 DUL and RBL -127.1.0.4 RSS -127.1.0.5 RSS and RBL -127.1.0.6 RSS and DUL -127.1.0.7 RSS and DUL and RBL -.endd +.itable none 0 0 2 20* left 80* left +.irow 127.1.0.1 "RBL" +.irow 127.1.0.2 "DUL" +.irow 127.1.0.3 "DUL and RBL" +.irow 127.1.0.4 "RSS" +.irow 127.1.0.5 "RSS and RBL" +.irow 127.1.0.6 "RSS and DUL" +.irow 127.1.0.7 "RSS and DUL and RBL" +.endtable Section &<>& below describes how you can distinguish between different values. Some DNS lists may return more than one address record; see section &<>& for details of how they are checked. @@ -32710,7 +32716,7 @@ may start returning other addresses. Because of this, Exim now ignores returned values outside the 127/8 region. -.section "Variables set from DNS lists" "SECID204" +.subsection "Variables set from DNS lists" SECID204 .cindex "expansion" "variables, set from DNS list" .cindex "DNS list" "variables set from" .vindex "&$dnslist_domain$&" @@ -32756,7 +32762,7 @@ deny hosts = !+local_networks -.section "Additional matching conditions for DNS lists" "SECTaddmatcon" +.subsection "Additional matching conditions for DNS lists" SECTaddmatcon .cindex "DNS list" "matching specific returned data" You can add an equals sign and an IP address after a &%dnslists%& domain name in order to restrict its action to DNS records with a matching right hand side. @@ -32802,7 +32808,7 @@ an odd number. -.section "Negated DNS matching conditions" "SECID205" +.subsection "Negated DNS matching conditions" SECID205 You can supply a negative list of IP addresses as part of a &%dnslists%& condition. Whereas .code @@ -32856,7 +32862,7 @@ deny dnslists = zen.spamhaus.org!&0.255.255.0 -.section "Handling multiple DNS records from a DNS list" "SECThanmuldnsrec" +.subsection "Handling multiple DNS records from a DNS list" SECThanmuldnsrec A DNS lookup for a &%dnslists%& condition may return more than one DNS record, thereby providing more than one IP address. When an item in a &%dnslists%& list is followed by &`=`& or &`&&`& and a list of IP addresses, in order to restrict @@ -32920,7 +32926,7 @@ between &`=`& and &`==`& and between &`&&`& and &`=&&`&. -.section "Detailed information from merged DNS lists" "SECTmordetinf" +.subsection "Detailed information from merged DNS lists" SECTmordetinf .cindex "DNS list" "information from merged" When the facility for restricting the matching IP values in a DNS list is used, the text from the TXT record that is set in &$dnslist_text$& may not reflect @@ -32969,7 +32975,7 @@ done. Only if there is a match is one of the more specific lists consulted. -.section "DNS lists and IPv6" "SECTmorednslistslast" +.subsection "DNS lists and IPv6" SECTmorednslistslast .cindex "IPv6" "DNS black lists" .cindex "DNS list" "IPv6 usage" If Exim is asked to do a dnslist lookup for an IPv6 address, it inverts it @@ -33003,16 +33009,15 @@ address you should specify alternate list separators for both the outer .endd -.new .section "Previously seen user and hosts" "SECTseen" -.cindex "&%sseen%& ACL condition" +.cindex "&%seen%& ACL condition" .cindex greylisting The &%seen%& ACL condition can be used to test whether a situation has been previously met. It uses a hints database to record a timestamp against a key. -host. The syntax of the condition is: +The syntax of the condition is: .display -&`seen =`& <&'time interval'&> &`/`& <&'options'&> +&`seen =`& <&'optional flag'&><&'time interval'&> &`/`& <&'options'&> .endd For example, @@ -33021,8 +33026,10 @@ defer seen = -5m / key=${sender_host_address}_$local_part@$domain .endd in a RCPT ACL will implement simple greylisting. -The parameters for the condition -are an interval followed, slash-separated, by a list of options. +The parameters for the condition are +a possible minus sign, +then an interval, +then, slash-separated, a list of options. The interval is taken as an offset before the current time, and used for the test. If the interval is preceded by a minus sign then the condition returns @@ -33040,6 +33047,8 @@ no record create or update is done. If a &%write%& option is given then a record create or update is always done. An update is done if the test is for &"since"&. +If none of those hold and there was no existing record, +a record is created. Creates and updates are marked with the current time. @@ -33052,7 +33061,6 @@ An explicit interval can be set using a Note that &"seen"& should be added to the list of hints databases for maintenance if this ACL condition is used. -.wen .section "Rate limiting incoming messages" "SECTratelimiting" @@ -33123,18 +33131,25 @@ behaviour. The lookup key is not affected by changes to the update mode and the &%count=%& option. -.section "Ratelimit options for what is being measured" "ratoptmea" +.subsection "Ratelimit options for what is being measured" ratoptmea .cindex "rate limiting" "per_* options" -The &%per_conn%& option limits the client's connection rate. It is not +.vlist +.vitem per_conn +.cindex "rate limiting" per_conn +This option limits the client's connection rate. It is not normally used in the &%acl_not_smtp%&, &%acl_not_smtp_mime%&, or &%acl_not_smtp_start%& ACLs. -The &%per_mail%& option limits the client's rate of sending messages. This is +.vitem per_mail +.cindex "rate limiting" per_conn +This option limits the client's rate of sending messages. This is the default if none of the &%per_*%& options is specified. It can be used in &%acl_smtp_mail%&, &%acl_smtp_rcpt%&, &%acl_smtp_predata%&, &%acl_smtp_mime%&, &%acl_smtp_data%&, or &%acl_not_smtp%&. -The &%per_byte%& option limits the sender's email bandwidth. It can be used in +.vitem per_byte +.cindex "rate limiting" per_conn +This option limits the sender's email bandwidth. It can be used in the same ACLs as the &%per_mail%& option, though it is best to use this option in the &%acl_smtp_mime%&, &%acl_smtp_data%& or &%acl_not_smtp%& ACLs; if it is used in an earlier ACL, Exim relies on the SIZE parameter given by the client @@ -33142,7 +33157,9 @@ in its MAIL command, which may be inaccurate or completely missing. You can follow the limit &'m'& in the configuration with K, M, or G to specify limits in kilobytes, megabytes, or gigabytes, respectively. -The &%per_rcpt%& option causes Exim to limit the rate at which recipients are +.vitem per_rcpt +.cindex "rate limiting" per_rcpt +This 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%&, or &%acl_smtp_data%& ACLs. In &%acl_smtp_rcpt%& the rate is updated one recipient at a time; in the other @@ -33150,27 +33167,40 @@ ACLs the rate is updated with the total (accepted) recipient count in one go. No in either case the rate limiting engine will see a message with many recipients as a large high-speed burst. -The &%per_addr%& option is like the &%per_rcpt%& option, except it counts the +.vitem per_addr +.cindex "rate limiting" per_addr +This option is like the &%per_rcpt%& option, except it counts the number of different recipients that the client has sent messages to in the last time period. That is, if the client repeatedly sends messages to the same recipient, its measured rate is not increased. This option can only be used in &%acl_smtp_rcpt%&. -The &%per_cmd%& option causes Exim to recompute the rate every time the +.vitem per_cmd +.cindex "rate limiting" per_cmd +This option causes Exim to recompute the rate every time the condition is processed. This can be used to limit the rate of any SMTP command. If it is used in multiple ACLs it can limit the aggregate rate of multiple different commands. -The &%count=%& option can be used to alter how much Exim adds to the client's -measured rate. For example, the &%per_byte%& option is equivalent to -&`per_mail/count=$message_size`&. If there is no &%count=%& option, Exim +.vitem count +.cindex "rate limiting" count +This option can be used to alter how much Exim adds to the client's +measured rate. +A value is required, after an equals sign. +For example, the &%per_byte%& option is equivalent to +&`per_mail/count=$message_size`&. +If there is no &%count=%& option, Exim increases the measured rate by one (except for the &%per_rcpt%& option in ACLs -other than &%acl_smtp_rcpt%&). The count does not have to be an integer. +other than &%acl_smtp_rcpt%&). +The count does not have to be an integer. -The &%unique=%& option is described in section &<>& below. +.vitem unique +.cindex "rate limiting" unique +This option is described in section &<>& below. +.endlist -.section "Ratelimit update modes" "ratoptupd" +.subsection "Ratelimit update modes" ratoptupd .cindex "rate limiting" "reading data without updating" You can specify one of three options with the &%ratelimit%& condition to control when its database is updated. This section describes the &%readonly%& @@ -33211,7 +33241,7 @@ update mode defaults to &%readonly%& and you cannot specify the &%strict%& or next section) so you must specify the &%readonly%& option explicitly. -.section "Ratelimit options for handling fast clients" "ratoptfast" +.subsection "Ratelimit options for handling fast clients" ratoptfast .cindex "rate limiting" "strict and leaky modes" If a client's average rate is greater than the maximum, the rate limiting engine can react in two possible ways, depending on the presence of the @@ -33242,7 +33272,7 @@ attempt to send mail can be calculated with this formula: .endd -.section "Limiting the rate of different events" "ratoptuniq" +.subsection "Limiting the rate of different events" ratoptuniq .cindex "rate limiting" "counting unique events" The &%ratelimit%& &%unique=%& option controls a mechanism for counting the rate of different events. For example, the &%per_addr%& option uses this @@ -33280,7 +33310,7 @@ are logged incorrectly; any countermeasures you configure will be as effective as intended. -.section "Using rate limiting" "useratlim" +.subsection "Using rate limiting" useratlim Exim's other ACL facilities are used to define what counter-measures are taken when the rate limit is exceeded. This might be anything from logging a warning (for example, while measuring existing sending rates in order to define @@ -33497,10 +33527,17 @@ output before performing a callout in an ACL, to avoid unexpected timeouts in clients when the SMTP PIPELINING extension is in use. The flushing can be disabled by using a &%control%& modifier to set &%no_callout_flush%&. +.cindex "tainted data" "de-tainting" +.cindex "de-tainting" "using recipient verify" +A recipient callout which gets a 2&'xx'& code +will assign untainted values to the +&$domain_data$& and &$local_part_data$& variables, +corresponding to the domain and local parts of the recipient address. + -.section "Additional parameters for callouts" "CALLaddparcall" +.subsection "Additional parameters for callouts" CALLaddparcall .cindex "callout" "additional parameters for" The &%callout%& option can be followed by an equals sign and a number of optional parameters, separated by commas. For example: @@ -33688,7 +33725,7 @@ actual callouts are performed than when an empty sender or postmaster is used. -.section "Callout caching" "SECTcallvercache" +.subsection "Callout caching" SECTcallvercache .cindex "hints database" "callout cache" .cindex "callout" "cache, description of" .cindex "caching" "callout" @@ -33700,7 +33737,7 @@ a specific address, and the other records information that applies to the entire domain (for example, that it accepts the local part &'postmaster'&). When an original callout fails, a detailed SMTP error message is given about -the failure. However, for subsequent failures use the cache data, this message +the failure. However, for subsequent failures that use the cache data, this message is not available. The expiry times for negative and positive address cache records are @@ -35323,10 +35360,8 @@ discussed below. .vitem &*header_line&~*header_last*& A pointer to the last of the header lines. -.new .vitem &*const&~uschar&~*headers_charset*& The value of the &%headers_charset%& configuration option. -.wen .vitem &*BOOL&~host_checking*& This variable is TRUE during a host checking session that is initiated by the @@ -35610,11 +35645,11 @@ added zero byte is not included in the returned count. .vitem &*int&~lss_match_domain(uschar&~*domain,&~uschar&~*list)*& This function checks for a match in a domain list. Domains are always matched caselessly. The return value is one of the following: -.display -&`OK `& match succeeded -&`FAIL `& match failed -&`DEFER `& match deferred -.endd +.itable none 0 0 2 15* left 85* left +.irow &`OK`& "match succeeded" +.irow &`FAIL`& "match failed" +.irow &`DEFER`& "match deferred" +.endtable DEFER is usually caused by some kind of lookup defer, such as the inability to contact a database. @@ -35849,6 +35884,7 @@ The system filter is run at the start of a delivery attempt, before any routing is done. If a message fails to be completely delivered at the first attempt, the system filter is run again at the start of every retry. If you want your filter to do something only once per message, you can make use +.cindex retry condition of the &%first_delivery%& condition in an &%if%& command in the filter to prevent it happening on retries. @@ -36345,7 +36381,8 @@ incoming SMTP message from a source that is not permitted to send them. -.section "Resent- header lines" "SECID220" +.section "Header lines" +.subsection "Resent- header lines" SECID220 .chindex Resent- RFC 2822 makes provision for sets of header lines starting with the string &`Resent-`& to be added to a message when it is resent by the original @@ -36386,14 +36423,14 @@ The logic for adding &'Sender:'& is duplicated for &'Resent-Sender:'& when any -.section "The Auto-Submitted: header line" "SECID221" +.subsection Auto-Submitted: SECID221 Whenever Exim generates an autoreply, a bounce, or a delay warning message, it includes the header line: .code Auto-Submitted: auto-replied .endd -.section "The Bcc: header line" "SECID222" +.subsection Bcc: SECID222 .cindex "&'Bcc:'& header line" If Exim is called with the &%-t%& option, to take recipient addresses from a message's header, it removes any &'Bcc:'& header line that may exist (after @@ -36401,13 +36438,13 @@ extracting its addresses). If &%-t%& is not present on the command line, any existing &'Bcc:'& is not removed. -.section "The Date: header line" "SECID223" +.subsection Date: SECID223 .cindex Date: If a locally-generated or submission-mode message has no &'Date:'& header line, Exim adds one, using the current date and time, unless the &%suppress_local_fixups%& control has been specified. -.section "The Delivery-date: header line" "SECID224" +.subsection Delivery-date: SECID224 .cindex "&'Delivery-date:'& header line" .oindex "&%delivery_date_remove%&" &'Delivery-date:'& header lines are not part of the standard RFC 2822 header @@ -36418,7 +36455,7 @@ set (the default), Exim removes &'Delivery-date:'& header lines from incoming messages. -.section "The Envelope-to: header line" "SECID225" +.subsection Envelope-to: SECID225 .chindex Envelope-to: .oindex "&%envelope_to_remove%&" &'Envelope-to:'& header lines are not part of the standard RFC 2822 header set. @@ -36429,7 +36466,7 @@ messages in transit. If the &%envelope_to_remove%& configuration option is set messages. -.section "The From: header line" "SECTthefrohea" +.subsection From: SECTthefrohea .chindex From: .cindex "Sendmail compatibility" "&""From""& line" .cindex "message" "submission" @@ -36472,7 +36509,7 @@ user, this is replaced by an address containing the user's login name and full name as described in section &<>&. -.section "The Message-ID: header line" "SECID226" +.subsection Message-ID: SECID226 .chindex Message-ID: .cindex "message" "submission" .oindex "&%message_id_header_text%&" @@ -36487,7 +36524,7 @@ in this header line by setting the &%message_id_header_text%& and/or &%message_id_header_domain%& options. -.section "The Received: header line" "SECID227" +.subsection Received: SECID227 .chindex Received: A &'Received:'& header line is added at the start of every message. The contents are defined by the &%received_header_text%& configuration option, and @@ -36503,7 +36540,7 @@ changed to the time of acceptance, which is (apart from a small delay while the -H spool file is written) the earliest time at which delivery could start. -.section "The References: header line" "SECID228" +.subsection References: SECID228 .chindex References: Messages created by the &(autoreply)& transport include a &'References:'& header line. This is constructed according to the rules that are described in @@ -36517,7 +36554,7 @@ incoming message. If there are more than 12, the first one and then the final -.section "The Return-path: header line" "SECID229" +.subsection Return-path: SECID229 .chindex Return-path: .oindex "&%return_path_remove%&" &'Return-path:'& header lines are defined as something an MTA may insert when @@ -36528,7 +36565,7 @@ default), Exim removes &'Return-path:'& header lines from incoming messages. -.section "The Sender: header line" "SECTthesenhea" +.subsection Sender: SECTthesenhea .cindex "&'Sender:'& header line" .cindex "message" "submission" .chindex Sender: @@ -36933,7 +36970,7 @@ square bracket of the IP address. -.section "Errors in outgoing SMTP" "SECToutSMTPerr" +.subsection "Errors in outgoing SMTP" SECToutSMTPerr .cindex "error" "in outgoing SMTP" .cindex "SMTP" "errors in outgoing" .cindex "host" "error" @@ -37168,7 +37205,7 @@ however, available with &'inetd'&. Exim can be configured to verify addresses in incoming SMTP commands as they are received. See chapter &<>& for details. It can also be configured to rewrite addresses at this time &-- before any syntax checking is done. See -section &<>&. +section &<>&. Exim can also be configured to limit the rate at which a client host submits MAIL and RCPT commands in a single SMTP session. See the @@ -37176,7 +37213,7 @@ MAIL and RCPT commands in a single SMTP session. See the -.section "Unrecognized SMTP commands" "SECID234" +.subsection "Unrecognized SMTP commands" SECID234 .cindex "SMTP" "unrecognized commands" If Exim receives more than &%smtp_max_unknown_commands%& unrecognized SMTP commands during a single SMTP connection, it drops the connection after sending @@ -37186,7 +37223,7 @@ abuse that subvert web servers into making connections to SMTP ports; in these circumstances, a number of non-SMTP lines are sent first. -.section "Syntax and protocol errors in SMTP commands" "SECID235" +.subsection "Syntax and protocol errors in SMTP commands" SECID235 .cindex "SMTP" "syntax errors" .cindex "SMTP" "protocol errors" A syntax error is detected if an SMTP command is recognized, but there is @@ -37200,7 +37237,7 @@ broken clients that loop sending bad commands (yes, it has been seen). -.section "Use of non-mail SMTP commands" "SECID236" +.subsection "Use of non-mail SMTP commands" SECID236 .cindex "SMTP" "non-mail commands" The &"non-mail"& SMTP commands are those other than MAIL, RCPT, and DATA. Exim counts such commands, and drops the connection if there are too @@ -37229,7 +37266,7 @@ specific badly-behaved hosts that you have to live with. -.section "The VRFY and EXPN commands" "SECID237" +.subsection "The VRFY and EXPN commands" SECID237 When Exim receives a VRFY or EXPN command on a TCP/IP connection, it runs the ACL specified by &%acl_smtp_vrfy%& or &%acl_smtp_expn%& (as appropriate) in order to decide whether the command should be accepted or not. @@ -37250,12 +37287,12 @@ EXPN is treated as an &"address test"& (similar to the &%-bt%& option) rather than a verification (the &%-bv%& option). If an unqualified local part is given as the argument to EXPN, it is qualified with &%qualify_domain%&. Rejections of VRFY and EXPN commands are logged on the main and reject logs, and -VRFY verification failures are logged on the main log for consistency with +VRFY verification failures are logged in the main log for consistency with RCPT failures. -.section "The ETRN command" "SECTETRN" +.subsection "The ETRN command" SECTETRN .cindex "ETRN" "processing" .cindex "ESMTP extensions" ETRN RFC 1985 describes an ESMTP command called ETRN that is designed to @@ -38321,7 +38358,7 @@ LOG_FILE_PATH, and uses the first item it finds that is neither empty nor &"syslog"&. This means that an empty item in &%log_file_path%& can be used to mean &"use the path specified at build time"&. If no such item exists, log files are written in the &_log_& subdirectory of the spool directory. This is -equivalent to the setting: +equivalent to the configuration file setting: .code log_file_path = $spool_directory/log/%slog .endd @@ -38332,7 +38369,7 @@ that is where the logs are written. A log file path may also contain &`%D`& or &`%M`& if datestamped log filenames are in use &-- see section &<>& below. -Here are some examples of possible settings: +Here are some examples of possible Makefile settings: .display &`LOG_FILE_PATH=syslog `& syslog only &`LOG_FILE_PATH=:syslog `& syslog and default path @@ -38507,16 +38544,16 @@ One line is written to the main log for each message received, and for each successful, unsuccessful, and delayed delivery. These lines can readily be picked out by the distinctive two-character flags that immediately follow the timestamp. The flags are: -.display -&`<=`& message arrival -&`(=`& message fakereject -&`=>`& normal message delivery -&`->`& additional address in same delivery -&`>>`& cutthrough message delivery -&`*>`& delivery suppressed by &%-N%& -&`**`& delivery failed; address bounced -&`==`& delivery deferred; temporary problem -.endd +.itable none 0 0 2 10* left 90* left +.irow &%<=%& "message arrival" +.irow &%(=%& "message fakereject" +.irow &%=>%& "normal message delivery" +.irow &%->%& "additional address in same delivery" +.irow &%>>%& "cutthrough message delivery" +.irow &%*>%& "delivery suppressed by &%-N%&" +.irow &%**%& "delivery failed; address bounced" +.irow &%==%& "delivery deferred; temporary problem" +.endtable .section "Logging message reception" "SECID251" @@ -38835,65 +38872,64 @@ log_selector = +arguments -retry_defer .endd The list of optional log items is in the following table, with the default selection marked by asterisks: -.display -&` 8bitmime `& received 8BITMIME status -&`*acl_warn_skipped `& skipped &%warn%& statement in ACL -&` address_rewrite `& address rewriting -&` all_parents `& all parents in => lines -&` arguments `& command line arguments -&`*connection_reject `& connection rejections -&`*delay_delivery `& immediate delivery delayed -&` deliver_time `& time taken to attempt delivery -&` delivery_size `& add &`S=`&&'nnn'& to => lines -&`*dkim `& DKIM verified domain on <= lines -&` dkim_verbose `& separate full DKIM verification result line, per signature -&`*dnslist_defer `& defers of DNS list (aka RBL) lookups -&` dnssec `& DNSSEC secured lookups -&`*etrn `& ETRN commands -&`*host_lookup_failed `& as it says -&` ident_timeout `& timeout for ident connection -&` incoming_interface `& local interface on <= and => lines -&` incoming_port `& remote port on <= lines -&`*lost_incoming_connection `& as it says (includes timeouts) -&` millisec `& millisecond timestamps and RT,QT,DT,D times -&`*msg_id `& on <= lines, Message-ID: header value -&` msg_id_created `& on <= lines, Message-ID: header value when one had to be added -&` outgoing_interface `& local interface on => lines -&` outgoing_port `& add remote port to => lines -&`*queue_run `& start and end queue runs -&` queue_time `& time on queue for one recipient -&`*queue_time_exclusive `& exclude recieve time from QT times -&` queue_time_overall `& time on queue for whole message -&` pid `& Exim process id -&` pipelining `& PIPELINING use, on <= and => lines -&` proxy `& proxy address on <= and => lines -&` receive_time `& time taken to receive message -&` received_recipients `& recipients on <= lines -&` received_sender `& sender on <= lines -&`*rejected_header `& header contents on reject log -&`*retry_defer `& &"retry time not reached"& -&` return_path_on_delivery `& put return path on => and ** lines -&` sender_on_delivery `& add sender to => lines -&`*sender_verify_fail `& sender verification failures -&`*size_reject `& rejection because too big -&`*skip_delivery `& delivery skipped in a queue run -&`*smtp_confirmation `& SMTP confirmation on => lines -&` 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 -&`*tls_certificate_verified `& certificate verification status -&`*tls_cipher `& TLS cipher suite on <= and => lines -&` tls_peerdn `& TLS peer DN on <= and => lines -&` tls_resumption `& append * to cipher field -&` tls_sni `& TLS SNI on <= lines -&` unknown_in_list `& DNS lookup failed in list match - -&` all `& all of the above -.endd +.itable none 0 0 3 2.8in left 10pt center 3in left +.irow &`8bitmime`&   "received 8BITMIME status" +.irow &`acl_warn_skipped`& * "skipped &%warn%& statement in ACL" +.irow &`address_rewrite`&   "address rewriting" +.irow &`all_parents`&   "all parents in => lines" +.irow &`arguments`&   "command line arguments" +.irow &`connection_reject`& * "connection rejections" +.irow &`delay_delivery`& * "immediate delivery delayed" +.irow &`deliver_time`&   "time taken to attempt delivery" +.irow &`delivery_size`&   "add &`S=`&&'nnn'& to => lines" +.irow &`dkim`& * "DKIM verified domain on <= lines" +.irow &`dkim_verbose`&   "separate full DKIM verification result line, per signature" +.irow &`dnslist_defer`& * "defers of DNS list (aka RBL) lookups" +.irow &`dnssec`&   "DNSSEC secured lookups" +.irow &`etrn`& * "ETRN commands" +.irow &`host_lookup_failed`& * "as it says" +.irow &`ident_timeout`&   "timeout for ident connection" +.irow &`incoming_interface`&   "local interface on <= and => lines" +.irow &`incoming_port`&   "remote port on <= lines" +.irow &`lost_incoming_connection`& * "as it says (includes timeouts)" +.irow &`millisec`&   "millisecond timestamps and RT,QT,DT,D times" +.irow &`msg_id`& * "on <= lines, Message-ID: header value" +.irow &`msg_id_created`&   "on <= lines, Message-ID: header value when one had to be added" +.irow &`outgoing_interface`&   "local interface on => lines" +.irow &`outgoing_port`&   "add remote port to => lines" +.irow &`queue_run`& * "start and end queue runs" +.irow &`queue_time`&   "time on queue for one recipient" +.irow &`queue_time_exclusive`&   "exclude recieve time from QT times" +.irow &`queue_time_overall`&   "time on queue for whole message" +.irow &`pid`&   "Exim process id" +.irow &`pipelining`&   "PIPELINING use, on <= and => lines" +.irow &`proxy`&   "proxy address on <= and => lines" +.irow &`receive_time`&   "time taken to receive message" +.irow &`received_recipients`&   "recipients on <= lines" +.irow &`received_sender`&   "sender on <= lines" +.irow &`rejected_header`& * "header contents on reject log" +.irow &`retry_defer`& * "&&retry time not reached&&" +.irow &`return_path_on_delivery`&   "put return path on => and ** lines" +.irow &`sender_on_delivery`&   "add sender to => lines" +.irow &`sender_verify_fail`& * "sender verification failures" +.irow &`size_reject`& * "rejection because too big" +.irow &`skip_delivery`& * "delivery skipped in a queue run" +.irow &`smtp_confirmation`& * "SMTP confirmation on => lines" +.irow &`smtp_connection`&   "incoming SMTP connections" +.irow &`smtp_incomplete_transaction`&   "incomplete SMTP transactions" +.irow &`smtp_mailauth`&   "AUTH argument to MAIL commands" +.irow &`smtp_no_mail`&   "session with no MAIL commands" +.irow &`smtp_protocol_error`&   "SMTP protocol errors" +.irow &`smtp_syntax_error`&   "SMTP syntax errors" +.irow &`subject`&   "contents of &'Subject:'& on <= lines" +.irow &`tls_certificate_verified`& * "certificate verification status" +.irow &`tls_cipher`& * "TLS cipher suite on <= and => lines" +.irow &`tls_peerdn`&   "TLS peer DN on <= and => lines" +.irow &`tls_resumption`&   "append * to cipher field" +.irow &`tls_sni`&   "TLS SNI on <= lines" +.irow &`unknown_in_list`&   "DNS lookup failed in list match" +.irow &`all`&   "&*all of the above*&" +.endtable See also the &%slow_lookup_log%& main configuration option, section &<>& @@ -39089,7 +39125,7 @@ On accept lines, where PIPELINING was offered but not used by the client, the field has a minus appended. .cindex "pipelining" "early connection" -If Exim is built with the SUPPORT_PIPE_CONNECT build option +If Exim is built without the DISABLE_PIPE_CONNECT build option accept "L" fields have a period appended if the feature was offered but not used, or an asterisk appended if used. Delivery "L" fields have an asterisk appended if used. @@ -39391,12 +39427,12 @@ but the format of the output is different. For this reason, there are some system configuration options that configure exactly how &'exiwhat'& works. If it doesn't seem to be working for you, check the following compile-time options: -.display -&`EXIWHAT_PS_CMD `& the command for running &'ps'& -&`EXIWHAT_PS_ARG `& the argument for &'ps'& -&`EXIWHAT_EGREP_ARG `& the argument for &'egrep'& to select from &'ps'& output -&`EXIWHAT_KILL_ARG `& the argument for the &'kill'& command -.endd +.itable none 0 0 2 30* left 70* left +.irow &`EXIWHAT_PS_CMD`& "the command for running &'ps'&" +.irow &`EXIWHAT_PS_ARG`& "the argument for &'ps'&" +.irow &`EXIWHAT_EGREP_ARG`& "the argument for &'egrep'& to select from &'ps'& output" +.irow &`EXIWHAT_KILL_ARG`& "the argument for the &'kill'& command" +.endtable An example of typical output from &'exiwhat'& is .code 164 daemon: -q1h, listening on port 25 @@ -39491,9 +39527,7 @@ overriding the built-in one. .endlist There is one more option, &%-h%&, which outputs a list of options. -.new At least one selection option, or either the &*-c*& or &*-h*& option, must be given. -.wen @@ -39876,11 +39910,10 @@ in a transport) .cindex "&'exim_dumpdb'&" The entire contents of a database are written to the standard output by the &'exim_dumpdb'& program, -.new taking as arguments the spool and database names. -An option &'-z'& may be given to regest times in UTC; +An option &'-z'& may be given to request times in UTC; otherwise times are in the local timezone. -.wen +An option &'-k'& may be given to dump only the record keys. For example, to dump the retry database: .code exim_dumpdb /var/spool/exim retry @@ -39985,11 +40018,9 @@ resets the time of the next delivery attempt. Time values are given as a sequence of digit pairs for year, month, day, hour, and minute. Colons can be used as optional separators. -.new Both displayed and input times are in the local timezone by default. If an option &'-z'& is used on the command line, displayed times are in UTC. -.wen @@ -41012,7 +41043,6 @@ was received, in the conventional Unix form &-- the number of seconds since the start of the epoch. The second number is a count of the number of messages warning of delayed delivery that have been sent to the sender. -.new There follow a number of lines starting with a hyphen. These contain variables, can appear in any order, and are omitted when not relevant. @@ -41023,7 +41053,6 @@ If there is a value in parentheses, the data is quoted for a lookup. The following word specifies a variable, and the remainder of the item depends on the variable. -.wen .vlist .vitem "&%-acl%&&~<&'number'&>&~<&'length'&>" @@ -41342,8 +41371,8 @@ where you accept mail from relay sources (internal hosts or authenticated senders). -.section "Signing outgoing messages" "SECDKIMSIGN" -.cindex "DKIM" "signing" +.subsection "Signing outgoing messages" SECDKIMSIGN +.cindex DKIM signing For signing to be usable you must have published a DKIM record in DNS. Note that RFC 8301 (which does not cover EC keys) says: @@ -41368,6 +41397,7 @@ The domain(s) you want to sign with. After expansion, this can be a list. Each element in turn, lowercased, +.vindex "&$dkim_domain$&" is put into the &%$dkim_domain%& expansion variable while expanding the remaining signing options. If it is empty after expansion, DKIM signing is not done, @@ -41377,6 +41407,7 @@ and no error will result even if &%dkim_strict%& is set. This sets the key selector string. After expansion, which can use &$dkim_domain$&, this can be a list. Each element in turn is put in the expansion +.vindex "&$dkim_selector$&" variable &%$dkim_selector%& which may be used in the &%dkim_private_key%& option along with &%$dkim_domain%&. If the option is empty after expansion, DKIM signing is not done for this domain, @@ -41524,8 +41555,8 @@ both creation (t=) and expiry (x=) tags will be included. RFC 6376 lists these tags as RECOMMENDED. -.section "Verifying DKIM signatures in incoming mail" "SECDKIMVFY" -.cindex "DKIM" "verification" +.subsection "Verifying DKIM signatures in incoming mail" SECDKIMVFY +.cindex DKIM verification Verification of DKIM signatures in SMTP incoming email is done for all messages for which an ACL control &%dkim_disable_verify%& has not been set. @@ -41994,7 +42025,7 @@ The lookup will return the same result strings as can appear in -.section "SRS (Sender Rewriting Scheme)" SECTSRS +.subsection "SRS (Sender Rewriting Scheme)" SECTSRS .cindex SRS "sender rewriting scheme" SRS can be used to modify sender addresses when forwarding so that @@ -42030,6 +42061,7 @@ There is no need to periodically change this key; a timestamp is also encoded. The second argument should be given as the envelope sender address before this encoding operation. +If this value is empty the the expansion result will be empty. The third argument should be the recipient domain of the message when it arrived at this system. .endlist @@ -42115,7 +42147,8 @@ This description assumes that headers will be in /usr/local/include, and that the libraries are in /usr/local/lib. -. subsection +.subsection Configuration SSECDMARCCONFIG +.cindex DMARC configuration There are three main-configuration options: .cindex DMARC "configuration options" @@ -42156,9 +42189,9 @@ If not set (the default), the From: header is expanded from the dsn_from option, and <> is used for the envelope from. -. I wish we had subsections... - +.subsection Controls SSECDMARCCONTROLS .cindex DMARC controls + By default, the DMARC processing will run for any remote, non-authenticated user. It makes sense to only verify DMARC status of messages coming from remote, untrusted sources. You can @@ -42189,9 +42222,10 @@ send them.) There are no options to either control. Both must appear before the DATA acl. -. subsection +.subsection ACL SSECDMARCACL +.cindex DMARC "ACL condition" -DMARC checks cam be run on incoming SMTP messages by using the +DMARC checks can be run on incoming SMTP messages by using the &"dmarc_status"& ACL condition in the DATA ACL. You are required to call the &"spf"& condition first in the ACLs, then the &"dmarc_status"& condition. Putting this condition in the ACLs is required in order @@ -42203,16 +42237,16 @@ The &"dmarc_status"& condition takes a list of strings on its right-hand side. These strings describe recommended action based on the DMARC check. To understand what the policy recommendations mean, refer to the DMARC website above. Valid strings are: -.display -&'accept '& The DMARC check passed and the library recommends accepting the email. -&'reject '& The DMARC check failed and the library recommends rejecting the email. -&'quarantine '& The DMARC check failed and the library recommends keeping it for further inspection. -&'none '& The DMARC check passed and the library recommends no specific action, neutral. -&'norecord '& No policy section in the DMARC record for this RFC5322.From field -&'nofrom '& Unable to determine the domain of the sender. -&'temperror '& Library error or dns error. -&'off '& The DMARC check was disabled for this email. -.endd +.itable none 0 0 2 20* left 80* left +.irow &'accept'& "The DMARC check passed and the library recommends accepting the email" +.irow &'reject'& "The DMARC check failed and the library recommends rejecting the email" +.irow &'quarantine'& "The DMARC check failed and the library recommends keeping it for further inspection" +.irow &'none'& "The DMARC check passed and the library recommends no specific action, neutral" +.irow &'norecord'& "No policy section in the DMARC record for this RFC5322.From field" +.irow &'nofrom'& "Unable to determine the domain of the sender" +.irow &'temperror'& "Library error or dns error" +.irow &'off'& "The DMARC check was disabled for this email" +.endtable You can prefix each string with an exclamation mark to invert its meaning, for example "!accept" will match all results but "accept". The string list is evaluated left-to-right in a @@ -42257,7 +42291,8 @@ are "none", "reject" and "quarantine". It is blank when there is any error, including no DMARC record. .endlist -. subsection +.subsection Logging SSECDMARCLOGGING +.cindex DMARC logging By default, Exim's DMARC configuration is intended to be non-intrusive and conservative. To facilitate this, Exim will not @@ -42284,7 +42319,8 @@ Configure, somewhere before the DATA ACL, the control option to enable sending DMARC forensic reports .endlist -. subsection +.subsection Example SSECDMARCEXAMPLE +.cindex DMARC example Example usage: .code @@ -42378,13 +42414,13 @@ within &%proxy_protocol_timeout%&, which defaults to 3s. The following expansion variables are usable (&"internal"& and &"external"& here refer to the interfaces of the proxy): -.display -&'proxy_external_address '& IP of host being proxied or IP of remote interface of proxy -&'proxy_external_port '& Port of host being proxied or Port on remote interface of proxy -&'proxy_local_address '& IP of proxy server inbound or IP of local interface of proxy -&'proxy_local_port '& Port of proxy server inbound or Port on local interface of proxy -&'proxy_session '& boolean: SMTP connection via proxy -.endd +.itable none 0 0 2 30* left 70* left +.irow $proxy_external_address "IP of host being proxied or IP of remote interface of proxy" +.irow $proxy_external_port "Port of host being proxied or Port on remote interface of proxy" +.irow $proxy_local_address "IP of proxy server inbound or IP of local interface of proxy" +.irow $proxy_local_port "Port of proxy server inbound or Port on local interface of proxy" +.irow $proxy_session "boolean: SMTP connection via proxy" +.endtable If &$proxy_session$& is set but &$proxy_external_address$& is empty there was a protocol error. The variables &$sender_host_address$& and &$sender_host_port$& @@ -42431,15 +42467,15 @@ is an IP address and any subsequent elements are options. Options are a string =. The list of options is in the following table: -.display -&'auth '& authentication method -&'name '& authentication username -&'pass '& authentication password -&'port '& tcp port -&'tmo '& connection timeout -&'pri '& priority -&'weight '& selection bias -.endd +.itable none 0 0 2 10* left 90* left +.irow &'auth'& "authentication method" +.irow &'name'& "authentication username" +.irow &'pass'& "authentication password" +.irow &'port'& "tcp port" +.irow &'tmo'& "connection timeout" +.irow &'pri'& "priority" +.irow &'weight'& "selection bias" +.endtable More details on each of these options follows: @@ -42555,11 +42591,11 @@ This is usually for use in a Message Submission Agent context, but could be used for any message. If a value is appended it may be: -.display -&`1 `& mandatory downconversion -&`0 `& no downconversion -&`-1 `& if SMTPUTF8 not supported by destination host -.endd +.itable none 0 0 2 5* right 95* left +.irow &`1`& "mandatory downconversion" +.irow &`0`& "no downconversion" +.irow &`-1`& "if SMTPUTF8 not supported by destination host" +.endtable If no value is given, 1 is used. If mua_wrapper is set, the utf8_downconvert control @@ -42659,26 +42695,25 @@ Events have names which correspond to the point in process at which they fire. The name is placed in the variable &$event_name$& and the event action expansion must check this, as it will be called for every possible event type. -.new The current list of events is: -.display -&`dane:fail after transport `& per connection -&`msg:complete after main `& per message -&`msg:defer after transport `& per message per delivery try -&`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 host per delivery try; host errors -&`msg:fail:delivery after transport `& 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 -&`tls:fail:connect after main `& per connection -&`smtp:connect after transport `& per connection -&`smtp:ehlo after transport `& per connection -.endd -.wen +.itable all 0 0 4 25* left 10* center 15* center 50* left +.row auth:fail after both "per driver per authentication attempt" +.row dane:fail after transport "per connection" +.row msg:complete after main "per message" +.row msg:defer after transport "per message per delivery try" +.row msg:delivery after transport "per recipient" +.row msg:rcpt:host:defer after transport "per recipient per host" +.row msg:rcpt:defer after transport "per recipient" +.row msg:host:defer after transport "per host per delivery try; host errors" +.row msg:fail:delivery after transport "per recipient" +.row msg:fail:internal after main "per recipient" +.row tcp:connect before transport "per connection" +.row tcp:close after transport "per connection" +.row tls:cert before both "per certificate in verification chain" +.row tls:fail:connect after main "per connection" +.row smtp:connect after transport "per connection" +.row smtp:ehlo after transport "per connection" +.endtable New event types may be added in future. The event name is a colon-separated list, defining the type of @@ -42694,24 +42729,25 @@ should define the event action. An additional variable, &$event_data$&, is filled with information varying with the event type: -.display -&`dane:fail `& failure reason -&`msg:defer `& error string -&`msg:delivery `& smtp confirmation message -&`msg:fail:internal `& failure reason -&`msg:fail:delivery `& smtp error message -&`msg:host:defer `& error string -&`msg:rcpt:host:defer `& error string -&`msg:rcpt:defer `& error string -&`tls:cert `& verification chain depth -&`tls:fail:connect `& error string -&`smtp:connect `& smtp banner -&`smtp:ehlo `& smtp ehlo response -.endd +.itable all 0 0 2 20* left 80* left +.row auth:fail "smtp response" +.row dane:fail "failure reason" +.row msg:defer "error string" +.row msg:delivery "smtp confirmation message" +.row msg:fail:internal "failure reason" +.row msg:fail:delivery "smtp error message" +.row msg:host:defer "error string" +.row msg:rcpt:host:defer "error string" +.row msg:rcpt:defer "error string" +.row tls:cert "verification chain depth" +.row tls:fail:connect "error string" +.row smtp:connect "smtp banner" +.row smtp:ehlo "smtp ehlo response" +.endtable The :defer events populate one extra variable: &$event_defer_errno$&. -For complex operations an ACL expansion can be used in &%event_action%& +For complex operations an ACL expansion can be used in &%event_action%&, however due to the multiple contexts that Exim operates in during the course of its processing: .ilist @@ -42727,11 +42763,12 @@ 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 -&`tcp:connect `& do not connect -&`tls:cert `& refuse verification -&`smtp:connect `& close connection -.endd +.itable all 0 0 2 20* left 80* left +.row auth:fail "log information to write" +.row tcp:connect "do not connect" +.row tls:cert "refuse verification" +.row smtp:connect "close connection" +.endtable All other message types ignore the result string, and no other use is made of it.