On several occasions I have had the HTC Mail app stop syncing my work email from Exchange via ActiveSync. The calendar and contacts sync still appear to work, but mail stops flowing. If I look at the sync settings I see that when it tries to process mail a protocol error is reported and the sync fails. This has happened twice so far (about 7 - 10 days apart) and each time I've tried for more than a day to get the sync to work again with no luck. I've done things like deleting mail from the server around the time the sync stopped working, changing settings to get smaller amounts of email, cut out attachments, etc... none of that fixed the probelm. What has worked both times is to delete the exchange account and then re-add it. As soon as I do this, it starts working again. For a while. I expect I will be back in this situation in another week or two. Clearly it's not a problem on the server side or a delete/add of the account on my device would not fix it. Has anyone else run into this and found a better solution than wiping out the account?