Old Undeliverable / NDR's just showed up 1

[ls62]

Hi,

Our exchange 2003 server seemed to have been working fine. We were receiving and sending emails without any issue.

Yesterday we had to reboot the server and after it came back up many of our users started receiving a few 'undeliverable' NDR's from the system administrator for emails they had sent days and weeks ago. Not everyone received these but several users receive 3, 4, 5 of them.

Additionally I had one outside vendor call me because he 'just' received an email dated 8/5/2013. The odd thing about this email as that I sent it two people at the same domain. One of them I definately know recieved the email on the day I sent it, while the other didn't ... until today.

It seems like some of these emails (undeliverables and misc outbound emails) where stuck in exchange and then released when we rebooted.

Has anyone seen this before or have any explaination for what might of caused this?

Thanks
Lee

 

[ShackDaddy]

It typically has to do with files stored in the queue folders on the C: drive of the Exchange server. For one reason or another the file gets ignored or put aside (due to AV or greylisting, or processing glitch) it basically sits there until the next server restart, at which time it gets resubmitted to the outbound queue.

The most common reason is failure to appropriately respond to greylisting: the remote server answers the connection by saying "not right now, please attempt again after X number of minutes/hours". The sending server is supposed to put the email aside and retry later. But it doesn't do this properly. It's a known glitch...until the next time the server reboots or the SMTP service is restarted. Then whatever was neglected gets resubmitted and you have what you witnessed.

If you want to create a workaround to resolve this, write a script that restarts the SMTP service every night. That will release those emails (if there are any), so that delivery doesn't end up being weeks/months after they were put aside.

Hope that helps.

Dave Shackelford
ThirdTier.net

 

[ShackDaddy]

BTW, here's a thread discussing this same thing:

https://groups.google.com/forum/#!topic/microsoft.public.exchange.admin/KsfVz8hxlCc

Dave Shackelford
ThirdTier.net

 

[ls62]

Dave

Thanks for the response. I'll try the batch job reset and see how things work.

Lee

 

[ShackDaddy]

BTW, you may also want to check out this article. Apparently there's a hotfix for the specific problem:

http://support.microsoft.com/kb/950757

Dave Shackelford
ThirdTier.net