Hi, just wanted to let you know I solved my problem. In my case the issue was a particular email in the inbox on Exchange. The culprit was an email attachment. It was a tif file with Chinese characters in its name. This was from an Asia contact, so it was not corrupt per se, just caused the Droid to choke. I have seen this with Outlook before, so it was not a big surprise.
If it helps, this is how I went about fixing:
1. Create a folder that does not get synced with the Droid.
2. Move all the contents of your inbox to that folder.
3. Sync your Droid. If it syncs without a problem, your on to something.
4. Start moving items back into your inbox.
a. If you have an idea when the issues started, move all email that pre-dates the event first. This will save time and is a logical shortcut.
b. Sync your Droid. If you get all that email without crashing, again, your onto something.
5. Start moving smaller groups or one at a time -depending on your patience level. After each move, re-sync. If a corrupt - or merely undigestible - email is the culprit, it will crash at some point.
You can figure the rest I'm sure. Hope this helps.
Stephen