[Mimedefang] Blacklist vs Access_db

[David F. Skoll]

On Wed, 11 Dec 2002, Mycrom wrote:

> Spamassassin can only view and evaluate your headder "From" address as it
> just scannes the message body (The one you see in your e-mail client when
> you open the message). Only the MTA's in message transmission keep track of
> the real envelope "From" address.

This is correct.  However, some MTA's usually add a "Return-Path:" header
with the envelope address, which (theoretically) SpamAssassin could use.
I believe most Sendmail configurations add Return-Path:

Under MIMEDefang, the Return-Path: header does *not* exist yet (it only
gets added by Sendmail upon delivery), so SpamAssassin has no information
about the envelope sender.

Both the envelope sender and the From: header are easily faked, so they
are more useful (IMO) for whitelisting than for blacklisting.  And if
you are whitelisting someone, it's unlikely the From: header and envelope
sender will be different (except for mailing lists.)

--
David.