Here are simple steps to troubleshoot 'email is not syncing on particular device' problem:
- send test message to BB user that carries device in question
- open up BES log file with 'MAGT' component in the name
- look for 'Queuing new mail through notification' message in above log confirming that it was delivered to BES mailstore
- If above log message is found then it indicates that email message in question was delivered into the store and BB agent was notified about it, however agent failed to deliver it over to device. This indicates that the issue is most likely is on the RIM's side - i would try to investigate DISP, POLC, ROUT, SYNC for any obvious failures.
- if above log message is absent in MAGT log then it may indicate that connector failed to sync this message from zimbra server. In this case the first thing i would try to do is stopping BB controller and trying to repair corresponding zdb file (representing user in question) using scanPST utility. In addition, zcb log files maybe also be helpful in this case. Please use this link describing procedure on how to enable zcb logs:
ZCB and BES Logs - BlackBerry - Zimbra :: Wiki
If nothing helps, please open support case(support@zimbra.com) and submit:
- time when test message was sent
- MAGT + zcb logs covering above time