-SRS (Sender Rewriting Scheme) Support
+SRS (Sender Rewriting Scheme) Support (using libsrs_alt)
--------------------------------------------------------------
+See also below, for an alternative native support implementation.
-Exiscan currently includes SRS support via Miles Wilton's
+Exim currently includes SRS support via Miles Wilton's
libsrs_alt library. The current version of the supported
library is 0.5, there are reports of 1.0 working.
+SRS (Sender Rewriting Scheme) Support (native)
+--------------------------------------------------------------
+This is less full-featured than the libsrs_alt version above.
+
+The Exim build needs to be done with this in Local/Makefile:
+EXPERIMENTAL_SRS_NATIVE=yes
+
+The following are provided:
+- an expansion item "srs_encode"
+ This takes three arguments:
+ - a site SRS secret
+ - the return_path
+ - the pre-forwarding domain
+
+- an expansion condition "inbound_srs"
+ This takes two arguments: the local_part to check, and a site SRS secret.
+ If the secret is zero-length, only the pattern of the local_part is checked.
+ The $srs_recipient variable is set as a side-effect.
+
+- an expansion variable $srs_recipient
+ This gets the original return_path encoded in the SRS'd local_part
+
+- predefined macros _HAVE_SRS and _HAVE_NATIVE_SRS
+
+Sample usage:
+
+ #macro
+ SRS_SECRET = <pick something unique for your site for this>
+
+ #routers
+
+ outbound:
+ driver = dnslookup
+ # if outbound, and forwarding has been done, use an alternate transport
+ domains = ! +my_domains
+ transport = ${if eq {$local_part@$domain} \
+ {$original_local_part@$original_domain} \
+ {remote_smtp} {remote_forwarded_smtp}}
+
+ inbound_srs:
+ driver = redirect
+ senders = :
+ domains = +my_domains
+ # detect inbound bounces which are SRS'd, and decode them
+ condition = ${if inbound_srs {$local_part} {SRS_SECRET}}
+ data = $srs_recipient
+
+ inbound_srs_failure:
+ driver = redirect
+ senders = :
+ domains = +my_domains
+ # detect inbound bounces which look SRS'd but are invalid
+ condition = ${if inbound_srs {$local_part} {}}
+ allow_fail
+ data = :fail: Invalid SRS recipient address
+
+ #... further routers here
+
+
+ # transport; should look like the non-forward outbound
+ # one, plus the max_rcpt and return_path options
+ remote_forwarded_smtp:
+ driver = smtp
+ # modify the envelope from, for mails that we forward
+ max_rcpt = 1
+ return_path = ${srs_encode {SRS_SECRET} {$return_path} {$original_domain}}
+
+
+
+
DCC Support
--------------------------------------------------------------
Distributed Checksum Clearinghouse; http://www.rhyolite.com/dcc/
Specification: https://tools.ietf.org/html/draft-ietf-dmarc-arc-protocol-11
Note that this is not an RFC yet, so may change.
+[RFC 8617 was published 2019/06. Draft 11 was 2018/01. A review of the
+changes has not yet been done]
+
ARC is intended to support the utility of SPF and DKIM in the presence of
intermediaries in the transmission path - forwarders and mailinglists -
by establishing a cryptographically-signed chain in headers.
an intermediary. One might do verify for local destinations.
ARC uses the notion of a "ADministrative Management Domain" (ADMD).
-Described in RFC 5598 (section 2.3), this is essentially the set of
-mail-handling systems that the mail transits. A label should be chosen to
-identify the ADMD. Messages should be ARC-verified on entry to the ADMD,
-and ARC-signed on exit from it.
+Described in RFC 5598 (section 2.3), this is essentially a set of
+mail-handling systems that mail transits that are all under the control
+of one organisation. A label should be chosen to identify the ADMD.
+Messages should be ARC-verified on entry to the ADMD, and ARC-signed on exit
+from it.
Building with ARC Support
hosts_require_ocsp will fail
+
+Dovecot authenticator via inet socket
+------------------------------------
+If Dovecot is configured similar to :-
+
+service auth {
+...
+#SASL
+ inet_listener {
+ name = exim
+ port = 12345
+ }
+...
+}
+
+then an Exim authenticator can be configured :-
+
+ dovecot-plain:
+ driver = dovecot
+ public_name = PLAIN
+ server_socket = dovecot_server_name 12345
+ server_tls = true
+ server_set_id = $auth1
+
+If the server_socket does not start with a / it is taken as a hostname (or IP);
+and a whitespace-separated port number must be given.
+
+
+
+Twophase queue run fast ramp
+----------------------------
+To include this feature, add to Local/Makefile:
+ EXPERIMENTAL_QUEUE_RAMP=yes
+
+If the (added for this feature) main-section option "queue_fast_ramp" (boolean)
+is set, and a two-phase ("-qq") queue run finds, during the first phase, a
+suitably large number of message routed for a given host - then (subject to
+the usual queue-runner resource limits) delivery for that host is initiated
+immediately, overlapping with the remainder of the first phase.
+
+This is incompatible with queue_run_in_order.
+
+The result should be a faster startup of deliveries when a large queue is
+present and reasonable numbers of messages are routed to common hosts; this
+could be a smarthost case, or delivery onto the Internet where a large proportion
+of recipients hapen to be on a Gorilla-sized provider.
+
+As usual, the presence of a configuration option is associated with a
+predefined macro, making it possible to write portable configurations.
+For this one, the macro is _OPT_MAIN_QUEUE_FAST_RAMP.
+
+
+
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projects / exim.git / blobdiff