Long thread I haven't followed (just noticed) so haven't read everything (that'd take days), but just skimming through.

It started as "is it supported" then went in various directions. I can confirm trouble with Exch07, Google's EAS implementation and nuevasync. The problems vary depending on the server-side I'm using, but I can verify problems with receiving often 'server unavailable' messages (particularly with Google) that I've never had except very rarely for known issues (like not Internet connection :-/ )on any other device. I've used Google successfully with other mobile devices as well as a couple Macs (Calendar/Contacts - mail I just IMAP).

My biggest issue across all services is the N900's MfE doesn't a) pull over all fields per EAS protocol spec, b) doesn't properly map fields (Exch07/Google are most problematic - esp. calendar/contact notes), c) doesn't properly update N900 changes back to server, d) IM fields are not pulled into the contact they are associated with - for Google, this is really problematic - two IM addresses = 4 contacts in addition to the primary contact they came from which no longer has an IM info. Why 4 new contacts? 1 for IM address, 1 for email of that IM address x 2 = 4. Merge 50 on your phone to correct? Doesn't 'stick' - if you have to do a full resynch, you have to re-merge PLUS the 4 additional contacts created on the phone get stuck back on Google for you to go delete a couple hundred entries.

Nuevasync had so many problems (which is not the case with other devices I've used it on now and then) that after a couple hours, I went back to MfE -> Google/Exch07 direct because Nuevasync finally admitted that it seems to be a problem with how the EAS protocol was implemented.

So, I've noticed some asking for the code. If that's made available, that'd be great, but IMO there are so many issues, this should be a strong focus on Nokia/Maemo's end. I suspect the strong majority of users need this functionality whether for work or personal (Google). A BIG stretch would be to allow multiple accounts. A smaller stretch would be to support what many are growing used to and I see in forums of other devices that have implemented changes such as supporting multiple calendars (work/personal/shared) and multiple contact groups. IIRC, some are working on more than one account.

Sorry if I repeated what was said somewhere along the thread, but rather than running along smoothly with MfE by now after generations of it being out there (granted, it was on S60, I used Roadsync flawlessly on the N97 because MfE was so limited - including no HTML), a better description is I'm limping along having to do full resynchs too often.

Most of what I've noticed seems to be an issue with the protocol implementation.