This worked great for me
1 ) Go into your email from your desktop client
and delete or file away (archive) the latest emails that you suspect may’ve started to cause this issue.
2 ) From your Android device, go to Settings.
3 ) Select Applications
4 ) Select Manage Applications
5 ) Hit your Menu option/button (the one with four lines usually between the Back/Return button and the Home button)
6 ) Select Filter
7 ) Select Running in the Filter Options pop-up menu.
8 ) Scroll down and select Email. (If it’s not in the list, you probably killed it. Go back and start it first and then return to step 1.)
9 ) In the Email app’s Application Info screen, press the Clear data button. (Be advised that this will essentially clear all of your account info from the Email app, causing you to have to re-set everything up again like your login name, password, server names, etc. The exact prompt says, “All of this application’s data will be deleted permanently. This includes all files, settings, accounts, databases and so on.
” Don’t worry, this doesn’t mean it will delete your emails on the server.)
10 ) Open up the Email app again and it will prompt you to set everything up again (log in name, password, servers, etc.). Walah! The error message should now be gone.