We do not have a Blackberry Enterprise Server. (too expensive) Instead for each of our blackberry users, we create a contact in Active Directory and forward all of the users messages to the contact which has the firstname.lastname@example.org address. This generally works quite well.
Occasionally however, users will complain of receiving thousands of the same message to their blackberry. This occurs about once a week to a single user for a single message. (we have 40 BB users) When I look into the Exchange System Manager, I can clearly see that the message has several hundred Retries. (though not the thousands that the users report - no surprise)
My impression is that our server is sending the message, Blackberry is receiving it, but not confirming the reception and therefore our Server feels that there was an error and it was never really received. Eventually the message is delivered correctly and the repeating messages stop by themself. Alternatively, I can manually delete the offending message in ESM. Sometimes the messages are very large (7+mb), other times only a few kilobytes in size.
Event logs contain no warnings or errors. Our internet connect is not congested. (100mbit fiber). This problem only exists when communicating with Blackberry and no other domains. Blackberry and Rogers "have never heard of this problem", though I see that others online that are experiencing the problem as well. (with no posted resolution).
Any help would be appreciated!