My research and communications with Scalix Support on those Mail For Exchange Sync problems has resulted in the following:
MfE will not sync correctly and report a server error if a mail is in the Inbox that does not contain a "To:" in the header and is only addressed to or or more BCC receipients (as it is often the case with newsletters)
The bug can be reproduced easily by these steps:
- Create a new account, Premium user with Activesync rights
- Send testmail to account
- Configure E51 with latest firmware and latest MfE to sync mail.
- Everything works fine, the testmail can be seen on the Nokia
- Now send a mail to the account that has no "To:" recipient, only a single or multiple BCC recipients
- Try to sync the Nokia again: It will hang while syncing or fail with "Systemfehler: Versuchen sie es später erneut" (System Error: Try again later)
I've submitted those findings to Mr. Hoener from Support, and hope this will be fixed. As it currently stands, a single BCC-only email will prevent the entire Nokia eMail Sync from working.
I'm also publishing my findings here in case someone else stumbles upon problems with Nokia Devices (I would assume that not only the E51 is affected), so it's properly documented in the forums.