-$Cambridge: exim/doc/doc-misc/RFC.conform,v 1.1 2004/10/08 10:38:47 ph10 Exp $
-
Conformance with RFCs
---------------------
From: @a,@b:c@d
-is syntactally invalid. Exim does not enforce this restriction.
+is syntactically invalid. Exim does not enforce this restriction.
1.6 Local parts [3.4.1]
achieves what the user wants more often than other strategies.
-2.3 Use of EHLO/HELO [3.2]
---------------------------
-
-[Client MTAs should always start with EHLO, not HELO.]
-
-Exim sends EHLO only when it finds the string "ESMTP" in an SMTP greeting
-message. If EHLO is refused with a 5xx return code, it then reverts to HELO as
-required, but it does not contain logic for converting to HELO on other errors
-such as loss of connection or timeout after EHLO. That is one reason why it
-doesn't always send EHLO; there are reported to be ancient SMTP servers out
-there which collapse on receiving EHLO. (There is also at least one server
-whose banner reads "<host name> ignores ESMTP", but it is RFC 821 compliant in
-that it responds with 5O0 to EHLO, so Exim successfully reverts to HELO.)
-
-
-2.4 Closing the connection [4.1.1.10]
+2.3 Closing the connection [4.1.1.10]
-------------------------------------
[Client must wait for response to QUIT before closing the connection.]
bad behaviour.
-2.5 IPv6 address literals [4.1.2]
+2.4 IPv6 address literals [4.1.2]
---------------------------------
[IPv6 address literals are introduced by "IPv6".]
more widespread, Exim will follow whatever the common usage is.
-2.6 Underscores in domain names [4.1.2]
+2.5 Underscores in domain names [4.1.2]
---------------------------------------
[Underscores are not legal in domain names.]
some SMTP clients.)
-2.7 Removal of return-path headers [4.4]
+2.6 Removal of return-path headers [4.4]
----------------------------------------
[Relaying MTAs should not remove return-path.]
MTA for the same message.
-2.8 Randomizing the order of addresses of multihomed hosts [5]
+2.7 Randomizing the order of addresses of multihomed hosts [5]
--------------------------------------------------------------
[Multihomed host addresses should not be randomized.]
Exim does randomize a list of several addresses for a single host, because
-caching in resolvers will defeat the round-robinning that many namerservers
+caching in resolvers will defeat the round-robinning that many nameservers
use. (Note: this is not the same as randomizing equal-valued MX records. That
is required by the RFC.)
-2.9 Handling "MX points to self" [5]
+2.8 Handling "MX points to self" [5]
------------------------------------
[MX points to self must be treated as an error.]
differently, and there are several situations where this can be useful.
-2.10 Source routing [6.1]
+2.9 Source routing [6.1]
-------------------------
[Source routes should be stripped.]
forward-path.
-2.11 Loop detection [6.2]
+2.10 Loop detection [6.2]
-------------------------
[Loop count for Received: headers should be at least 100.]
even a couple of forwardings don't bring this anywhere near 30.
-2.12 Addition of missing headers [6.3]
+2.11 Addition of missing headers [6.3]
--------------------------------------
[Missing headers may be added, and domains qualified, only if client is
domains, it does so independently of the message's source.
-2.13 Syntax of MAIL and RCPT commands [4.1.1.2, 4.1.1.3]
+2.12 Syntax of MAIL and RCPT commands [4.1.1.2, 4.1.1.3]
--------------------------------------------------------
Exim is more relaxed than the RFC requires:
unquoted full stops.
-2.14 Non-fully-qualified domains [2.3.5]
+2.13 Non-fully-qualified domains [2.3.5]
----------------------------------------
[All domains must be fully qualified.]
used for this purpose.
-2.15 Unqualified addresses [4.1.2]
+2.14 Unqualified addresses [4.1.2]
----------------------------------
[Addresses in SMTP commands must include domains.]
<postmaster>) is qualified by adding the value of the qualify_domain option.
-2.16 VRFY and EXPN [3.5.1, 3.5.2, 3.5.3, 7.3]
+2.15 VRFY and EXPN [3.5.1, 3.5.2, 3.5.3, 7.3]
---------------------------------------------
[VRFY and EXPN should be supported.]
networks for which they are permitted can be given.
-2.17 Checking of EHLO/HELO commands [4.1.4]
+2.16 Checking of EHLO/HELO commands [4.1.4]
-------------------------------------------
[Client must send EHLO. Server must not refuse message if EHLO/HELO check
this check does not apply.
-2.18 Format of delivery error messages [3.7]
+2.17 Format of delivery error messages [3.7]
--------------------------------------------
[Standard report formats should be used if possible.]
-Exim's delivery failure reports do not conform to the format described in RFC
-1894.
+Exim's delivery failure reports are MIME format, and might be RFC1894
+conformant, but this has not been verified.
## End ##