Microsoft has confirmed problems with message delivery to BlackBerry mobile devices after installation of Rollup 4 for Microsoft Exchange 2010 SP2.
This issue occurs only in specific Microsoft Exchange and BlackBerry Enterprise Server environment.
In this scenario:
- You install Update Rollup 4 for Microsoft Exchange Server 2010 SP2 in an environment that is running against a Blackberry Enterprise Server (BES).
- The BES uses MAPI or Collaborative Data Objects (CDO), instead of Exchange Web Services (EWS), to communicate with Exchange servers.
- The mailbox contains many folders. For example, the mailbox contains more than 5000 folders.
You can encounter one or more of the following issues:
- Email message delivery to the mailbox on a BlackBerry mobile device is delayed.
- It takes a longer time to complete a folder hierarchy scan in the mailbox. For example, before Update Rollup 4 for Exchange Server 2010 SP2 was installed, a scan that typically takes 5 minutes may now take 30 minutes to 1 hour.
- The Microsoft Exchange Information Store process (store.exe) on the Exchange Mailbox server may use excessive CPU resources.
- Some BES event log entries are logged on the Exchange Mailbox server. Before Update Rollup 4 for Exchange Server 2010 SP2 was installed, these entries are less in occurrence or nonexistent.
- Some events are logged in the BlackBerry Messaging Agent (MAGT) log. These events that are logged in the BlackBerry MAGT log resemble the “Busy Working” threads that are described in the following article in the BlackBerry Knowledge Base: Users may experience delayed email after upgrading to Microsoft Exchange 2010 SP2 Rollup 4 or Microsoft Exchange 2010 SP2 Rollup 5
Currentl there is no HotFix to resolve those problems. Probably Rollup 6 for Exchange 2010 SP2 will fix this.
But Microsoft recommend below workaround:
Install Exchange Server Service Pack 2 RU 6 when it becomes available.
Add more agents on the BES if they are not already at the max of 15 agents.
Temporarily reduce the number of folders in the mailbox of the user.
Move all users who have high folder counts (>500) to their own instances of BESAgent.exe.
More informations you can find here: