[Mimedefang] Received headers in general

David F. Skoll dfs at roaringpenguin.com
Wed May 23 15:06:39 EDT 2012

On Wed, 23 May 2012 11:49:56 -0700 (PDT)
kd6lvw at yahoo.com wrote:

> Wrong.  It directly states that we can't reject on the basis of
> trying to enforce SMTP trace header syntax upon non-SMTP trace
> headers.  That is all.

Nope.  It says:

   "As another consequence of trace header fields arising in non-SMTP
    environments, receiving systems MUST NOT reject mail based on the
    format of a trace header field and SHOULD be extremely robust in
    the light of unexpected information or formats in those header

Read it carefully: It says non-standard header fields may arise
in non-SMTP environments.  It says we MUST NOT reject mail based on
the format of a trace header field.  That's *any* trace header field,
whether generated by SMTP or not.

[In fact, you could argue circularly that since Microsoft Exchange is
not SMTP-compliant, it is not an "SMTP" environment and therefore its
Received: headers should be accepted. :)]


> Precisely, and as spammers often generate non-compliant messages,

Do you have data to support that?  My feeling is that spammers are no
more non-compliant than legitimate senders.

> Given that, tell me why I should accept any inproperly formatted
> message, especially when spammers fail to comply?

Again, what *you* do personally is your business.  I just don't think
your recommendations are good for most people, nor is this specific
policy justifiable by appealing to the RFCs.

> cf. https://issues.apache.org/SpamAssassin/show_bug.cgi?id=6781

Yes, I see your comment, but you dismissed
https://issues.apache.org/SpamAssassin/show_bug.cgi?id=6781#c9 with
a rather ingeneous redefinition of spam ("If it violates the RFC, it's
not a valid message.")



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