Yesterday 3 users (out of over 700) were not receiving mail for over an hour. They had full coverage, units were rebooted several times, etc. But new messages would just sit pending in the queue. They could send messages successfully from the units though. They could not perform Lookups or certificate searches either. I could not re-send their policy or service book either because they would not reach the BB during this time frame.

There were no hung threads in my controller log and I didn't notice anything else in other logs. I did eventually stop and start the dispatcher and router service. Their pending messages reached their units, but I'm not certain if that fixed the problem or if it was coincidence.

What logs should I be checking to see what the problem was? Any ideas as to what would cause that problem? Other users on their Exchange server were working fine during that time also. I was right next to those people and my Blackberry worked fine and I could perform lookups and cert searches.

Thanks.

Several factors could affect the receipt of messages to some units. The fact that they could send means that the device is recognized on the wireless network. Not being able to do lookups/certificate searches means that the initial challenge response sent to the device was not acknowledged, hence the reason for pending messages. A look at the MAGT (messaging agent) and Synchronization logs may show some non-response items for affected users. The non-acknowledgement may be attributed to loss of connectivity by the device to wireless the network. The BES server however, maintains a constant, direct TCP/IP connection to the wireless network.
By restarting the dispatcher and router service, the BES server sends a fresh (refreshes) challenge response to the BES Infrastructure (NOC). This causes the refreshing of the challenge responses for each "active" device. Hence a flushing of pending messages for affected users.