Milter-greylist

Matthias Scheler wrote:
 > Emmanuel Dreyfus wrote:
 > > You can't fight on the HELO string, as the spammer can send whatever he
 > > wants. HELO filtering is only going to help in dealing with very special
 > > situations IMO.
 > 
 > But it works. I use "milter-regex" for this purpose and it rejected
 > 831 SMTP connections (on a low traffic mail server) which used
 > "HELO localhost" in the last 24 hours.

How many of those were spam?  And how many of those were
legitimate mails?  Can you even tell for sure?

It should be noted that using greylisting (which is still
the main purpose of milter-greylist) is perfectly RFC-
compliant.  But rejecting mails based on the HELO string
is not.

Therefore, if there's any mentioning of such HELO-based
filtering in the manpage or other docs, it should be
accompanied by a fat warning, IMHO.  So at least those
who intentionally make their servers violate the RFCs
are aware of it.

I expect that many people who use milter-greylist have
never read the appropriate RFCs.  The internet is becoming
more and more of a tough place because people don't read
standards or use "trial and error" methods.  I think that
milter-greylist should try not to make it worse, and at
least document the most critical things.  Milters often
operate at the very edge of RFC-compliance ...

Best regards
   Oliver

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Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M.
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