X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/e05f33e0b79c14608757a60f2f3f8588008355f7..13ca5f2522f4165a0aa6f1b7143a1a1cfa37bf5a:/doc/doc-misc/RFC.conform?ds=sidebyside diff --git a/doc/doc-misc/RFC.conform b/doc/doc-misc/RFC.conform index 2fc57cdf2..1ddd5b33d 100644 --- a/doc/doc-misc/RFC.conform +++ b/doc/doc-misc/RFC.conform @@ -1,5 +1,3 @@ -$Cambridge: exim/doc/doc-misc/RFC.conform,v 1.1 2004/10/08 10:38:47 ph10 Exp $ - Conformance with RFCs --------------------- @@ -100,7 +98,7 @@ enclosed in <> characters, so a header such as 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] @@ -182,22 +180,7 @@ incoming messages, but neither of these affect its handling of message data. 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 " 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.] @@ -216,7 +199,7 @@ before the response arrives. The subsequent arrival of the response then causes 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".] @@ -227,7 +210,7 @@ prefix. At present, it does not even recognize the prefix. When IPv6 becomes 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.] @@ -243,7 +226,7 @@ it will accept any old junk after EHLO or HELO. Such is the woeful state of 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.] @@ -254,18 +237,18 @@ not. Indeed, for some messages it might be both a relay and a final destination 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.] @@ -276,7 +259,7 @@ Exim configuration is compliant, but it is possible to configure Exim to behave 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.] @@ -288,7 +271,7 @@ does not add host routing to reverse-paths when processing a source-routed forward-path. -2.11 Loop detection [6.2] +2.10 Loop detection [6.2] ------------------------- [Loop count for Received: headers should be at least 100.] @@ -298,7 +281,7 @@ these days seem to accumulate less than half a dozen Received: headers, and 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 @@ -309,7 +292,7 @@ the source of the message, and likewise when it expands non-fully-qualified 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: @@ -327,7 +310,7 @@ 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.] @@ -343,7 +326,7 @@ as well as to locally-originated addresses. Address re-writing could also be 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.] @@ -360,7 +343,7 @@ domains in SMTP commands. Any such address that is accepted (including ) 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.] @@ -369,7 +352,7 @@ Exim does not support VRFY and EXPN by default, but a list of hosts and 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 @@ -389,13 +372,13 @@ It is possible to specify exception lists of hosts and/or networks for which 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 ##