RIM have release BlackBerry Enterprise Server Service Pack 3 Maintenance Release 7 for Microsoft Exchange Server.
The release includes new fixes for the BlackBerry Administration Service, BlackBerry Mail Store Service, BlackBerry MDS Connection Service, BlackBerry Messaging Agent and BlackBerry Policy Service
Select and download the update here, https://swdownloads.blackberry.com/Downloads/browseSoftware.do.
Installation is straight forward as usual and covered in the release notes, http://docs.blackberry.com/en/admin/deliverables/41482/BlackBerry_Enterprise_Server_for_Microsoft_Exchange-Maintenance_Release_Notes-1327683428293-5.0.3-en.pdf.