If you are having any problems with Exchange Activesync then this tool may be a great help. The AccessMyLan ActiveSync Tester simulates an ActiveSync client and provides a detailed diagnostic report with possible solution options. The tool can identify:
The ActiveSync Tester provides much more detailed and useful diagnostic and remediation information than handset ActiveSync error codes enabling you to quickly identify and resolve your ActiveSync issues. The tool does not transmit any user or server information to AccessMyLan.
You can get more details HERE