Okay, so here’s some common issues with BES and the fixes:

• Emails not being received on the device: This is the catch-all error. Things to check are: BES Admin permissions on Exchange, mapi32.dll and cdo.dll versions.
• Calendar appointments being received as emails: Almost certainly a CDO mismatch. Check the CDO versions.
• Calendar appointments not arriving: Could be to do with an obscure property of the AD user called homeMTA. If you are getting MAPI_E_NETWORK_ERROR errors in the MATG log, check this link: MAPI_E_NETWORK_ERROR