I have an Exchange 2010 server and BES Server too.
Only is happening with one user.
If i configure on and Android or on IOS, the mailbox with activesync works fine, i see all the email.
But, if i configure a Q5, or a Q10 (tried on both), the account for this user, even with activesync or with the BES server, i only see email till de 24th of November. I cant see emails newers than taht, while in android and ios i can.
I have delete and create the user on the BES server multiple times, i have move the users mailbox to another Exchange database, restart servers… nothing worked.
Any tips why only this happens on Blackberry devices?