Possible Blackberry Mail Delivery Delay with Exchange 2010

If this is not a performance issue due to:

• CPU issues on the CAS or Mailbox Servers

• Disk latencies on the Mailbox Server

Then consider the follwoing:- 

1) Update 5.0.2 Maintenance Release 4 of Blackberry Enterprise Server
2) Update MAPI/CDO on the BES servers to

Microsoft Exchange Server MAPI Client and Collaboration Data Objects 1.2.1
https://www.microsoft.com/downloads/en/details.aspx?familyid=E17E7F31-079A-43A9-BFF2-0A110307611E&displaylang=en

3) Exchange 2010 SP1 RU3 on the CAS and Mailbox server.

Still having problems ? Consider trying BES script/program to promote MAPI properties (From RIM)