Hi all,
We just had a case where we missed some mails from a vendor, and those mails now have arrived with three month delay. After some investigation we found the reason for the delay: the vendor is using Exchange 2003 SP2, which has a known, still unfixed bug. It causes outbound mail to domains that implement greylisting to be jailed in a black hole until the SMTP service is restarted.
If you are having an issue with greylisting, please review the problem description below. Should your problem match the description below and the workaround works for you, Microsoft has advised me to ask you to raise a support call with them. When you raise your support call, please ask that they link the call to the EMEA case SRZ060302000872. This way, should a number of customers be seeing the problem, it can be tracked within Microsoft.
SYMPTOMS =========
When Exchange tries to send mails to certain domains that implement "greylisting", the mails fail to get delivered, without any intimation to the sender on the first attempt. Thereafter on either restarting the server or SMTP service, the mails get delivered to the destination domains. At times, NDRs for these delayed mails are also generated after rebooting.
PROBLEM ========
The issue is intermittent and occurs only when the destination domains have greylisting implemented and mail is sent to the greylisted domain the very first time.
WORKAROUNDS ===========
1. Write a script to restart the SMTP service at least once a day. 2. Modify the registry on the sender Exchange server, to change the Glitch Retry key. 3. Clarify that there is no 3rd party AV software in the environment which could be causing the issue.
-- Martin
Martin Blapp, mb@imp.ch mbr@FreeBSD.org ------------------------------------------------------------------ ImproWare AG, UNIXSP & ISP, Zurlindenstrasse 29, 4133 Pratteln, CH Phone: +41 61 826 93 00 Fax: +41 61 826 93 01 PGP: <finger -l mbr@freebsd.org> PGP Fingerprint: B434 53FC C87C FE7B 0A18 B84C 8686 EF22 D300 551E ------------------------------------------------------------------