I’ve now seen this problem with 2 HTC Desire Android Phones.   

Exchange activesync will be working fine, then all of a sudden it’ll report a problem with the Exchange server – resulting in no further emails downloading.


There are two workarounds to this problem:

1) Delete your Exchange Account and re-add it again

2) Go to the account details screen and press “Save”

Hopefully the next Android release will fix this bug.