We have a new Exchange 2013 server and moved a few pilot users from the 2010 environment to it.
Everything seems to work OK but we just encountered a strange issue. One of the users turned on his automatic out of office replies and when people send E-mail to his mailbox they receive a 'Delivery delayed' e-mail. All mails to this account seem to be stuck in the queue (shown in the Exchange Toolbox – Queue viewer) but they DO actually arrive in his Outlook.
The error message in the queue for his messages is: Recipients: User@domain.com;3;3;[{LRT=};{LED=432 4.2.0 STOREDRV.Deliver; Agent transient failure during message resubmission[Agent: Mailbox Rules Agent]};{FQDN=};
After turning off his out of office replies, the queue emptied instantly, and no duplicate mails arrived in his mailbox. After turning it back on the queue started filling up again with new mails.
Other pilot users have the same issue.
Has anybody seen this issue before? I checked space on the drives and there seems to be no issue there (so no back pressure issue).
thanks!