[Mimedefang] OT - MS Exchange 2003 SP2 and greylisting

David F. Skoll dfs at roaringpenguin.com
Sat Jun 16 10:37:30 EDT 2007


Yizhar Hurwitz wrote:

> BTW - I have noticed the problem (at the sender side) against hosts that
> do greylisting at the "RCPT TO" stage,
> and haven't noticed it against hosts that greylist after DATA (such as
> Canit).

We do post-DATA greylisting in CanIt for this reason.  There were
other older MTAs (I think old versions of Novell Groupwise) that
didn't handle RCPT-time greylisting properly.  It seems like MSFT is
re-inventing old bugs. :-)

> I don't want to raise the argue about how good or bad greylisting is,
> just to mention the technical details to you all.

We find it is still surprisingly effective.  Log in as demo/demo to
see our statistics:

https://www.roaringpenguin.com/canit/statistics.php?pe=1&r=hourly-greylisting&domain=&cur_stream_only=0
https://www.roaringpenguin.com/canit/statistics.php?pe=1&r=daily-greylisting&domain=&cur_stream_only=0

"Entered Hit-and-Run" means a message was greylisted.  "Exited Hit-and-Run"
means a message was retransmitted.

Regards,

David.



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