[Mimedefang] Suggestions on rejecting relays that provide syntactically-invalid arguments to HELO/EHLO

[Joseph Brennan]

--On Friday, May 23, 2003 01:22 -0500 Michael Sims 
<michaels at crye-leike.com> wrote:

> For that reason I decided to create a wrapper function around
> spam_assassin_check() called my_spam_assassin_check().  I plan to use
> this to  do various tests inside MIMEDefang and then add the results to
> the spam  assassin score.  This way a non-fqdn HELO argument won't be
> bounced, it will  just increase the spam score of the message.  This I
> feel a little better about.


I've started doing something like this too.  Some factors related
to the smtp transaction are relevant to spamminess.  Note that
sendmail has not yet written the new Received header so Spamassassin
can't get at them with a header test (different from SA run out of
.procmailrc because at that stage the Received has been written).

We're interested in the HELO string, whether the remote host has
rDNS, and (for local reasons) the way the RCPT addresses are written.
At this point I get the score and test name in filter_begin() and
store them in variables.  If the message goes to Spamassassin in
filter_end(), then we add the Mimedefang-generated score and test
name to what SA said, just as in Michael's example.

Joseph Brennan          Columbia University in the City of New York
postmaster at columbia.edu                 Academic Technologies Group