X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/5ce637f7a74d392ddafb1d38e3cefb744996b287..43a1dac4b63c228775d92cdc2861b6f1e76c6f1f:/doc/doc-docbook/spec.xfpt diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index cc801a3a5..493c094cd 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -16640,15 +16640,21 @@ See also the ACL modifier &`control = suppress_local_fixups`&. Section .option localhost_number main string&!! unset .cindex "host" "locally unique number for" .cindex "message ids" "with multiple hosts" +.cindex multiple "systems sharing a spool" +.cindex "multiple hosts" "sharing a spool" +.cindex "shared spool directory" +.cindex "spool directory" sharing .vindex "&$localhost_number$&" Exim's message ids are normally unique only within the local host. If -uniqueness among a set of hosts is required, each host must set a different +uniqueness among a set of hosts is required +(eg. because they share a spool directory), +each host must set a different value for the &%localhost_number%& option. The string is expanded immediately after reading the configuration file (so that a number can be computed from the host name, for example) and the result of the expansion must be a number in the range 0&--16 (or 0&--10 on operating systems with case-insensitive file systems). This is available in subsequent string expansions via the variable -&$localhost_number$&. When &%localhost_number is set%&, the final two +&$localhost_number$&. When &%localhost_number%& is set, the final four characters of the message id, instead of just being a fractional part of the time, are computed from the time and the local host number as described in section &<>&. @@ -36455,8 +36461,6 @@ other MTAs, the way Exim handles line endings for all messages is now as follows: .ilist -LF not preceded by CR is treated as a line ending. -.next CR is treated as a line ending; if it is immediately followed by LF, the LF is ignored. .next @@ -36471,7 +36475,10 @@ people trying to play silly games. .next If the first header line received in a message ends with CRLF, a subsequent bare LF in a header line is treated in the same way as a bare CR in a header -line. +line and a bare LF in a body line is replaced with a space. +.next +If the first header line received in a message does not end with CRLF, a subsequent +LF not preceded by CR is treated as a line ending. .endlist @@ -39054,7 +39061,7 @@ selection marked by asterisks: .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 &`dkim_verbose`&   "separate full DKIM verification result line, per signature; DKIM signing" .irow &`dnslist_defer`& * "defers of DNS list (aka RBL) lookups" .irow &`dnssec`&   "DNSSEC secured lookups" .irow &`etrn`& * "ETRN commands" @@ -39180,6 +39187,10 @@ verifies successfully a tag of DKIM is added, with one of the verified domains. .cindex log "DKIM verification" .cindex DKIM "verification logging" &%dkim_verbose%&: A log entry is written for each attempted DKIM verification. +.new +Also, on message delivery lines signing information (domain and selector) +is added, tagged with DKIM=. +.wen .next .cindex "log" "dnslist defer" .cindex "DNS list" "logging defer" @@ -42236,10 +42247,16 @@ The lookup will return the same result strings as can appear in .subsection "SRS (Sender Rewriting Scheme)" SECTSRS .cindex SRS "sender rewriting scheme" +.cindex VERP "variable envelope return path" SRS can be used to modify sender addresses when forwarding so that SPF verification does not object to them. -It operates by encoding the original envelope sender in a new +It can also be used to identify a received bounce message as +likely (or not) having been trigged by a message from the +local system, and for identifying dead addresses in mailing lists. +It is one implementation of a VERP (Variable Envelope Return Path) method. + +SRS operates by encoding the original envelope sender in a new sender local part and using a domain run by the forwarding site as the new domain for the sender. Any DSN message should be returned to this new sender at the forwarding site, which can extract the