[Mimedefang] OT - MS Exchange 2003 SP2 and greylisting

[Yizhar Hurwitz]

HI.

I have just published a post at www.greylisting.org about a bug in MS 
Exchange 2003 SP2,
that sometimes fails to retry mails to greylisting hosts.

This isn't related directly to MD but I know that some MD users also 
implement greylisting,
and I think that it is important to know about this bug.

Here is the link to my recent post about this problem:
MS Exchange 2003 SP2 bug related to greylisting:
http://www.greylisting.org/forums/showthread.php?tid=18
If you are using greylisting - please also read the links in the 
discussion itself.

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).
That doesn't mean much because greylisting at DATA isn't common, but I 
think that it worth to mention.

BTW #2 - We have already disussed this problem here on the list at Feb-2006:
[Mimedefang] Re: Justifying greylisting to management:
http://lists.roaringpenguin.com/pipermail/mimedefang/2006-February/029632.html
I don't want to raise the argue about how good or bad greylisting is,
just to mention the technical details to you all.
I want to let you know that there is still a bug in MS Exchange 2003 SP2 
at the sending side,
and that the bug is sporadic, difficult to predict or track, so that you 
should be aware of it,
and know what to tell to the innocent Exchange admin that doesn't 
understand what happend,
and why his users complain about old emails being delayed for several weeks.

Bye

Yizhar Hurwitz
http://yizhar.mvps.org