1 month old System Undeliverables

[anothracount]

I just recently rebooted our exchange server, and about 15 users recieved bunch of undeliverable messages that they had sent anywhere from 1-45days prior to the reboot. They all got the undeliverables as soon as the server was rebooted.
Can anyone give me any ideas where or what caused this.
I m wondering where and why they were waiting for a reboot.

 

[Davetoo]

Could have been stuck in a queue. Really, you should be posting in the Exchange forums:

2000:

http://www.tek-tips.com/threadminder.cfm?pid=858

2003:

http://www.tek-tips.com/threadminder.cfm?pid=955

2007:

http://www.tek-tips.com/threadminder.cfm?pid=1582

I'm Certifiable, not cert-ified.
It just means my answers are from experience, not a book.