Intersting problem here. I have a user that gets the following error message when he tries to add a sender to his blocked senders list in OWA:
"an error occurred processing your junk e-mail lists. You are over the size limit allowed on the server."
We do not have any limits setup on the server making this error message more baffling. Furthermore, when he switched to Outlook 2003, he's able to add that sender to the blocked senders list.
We are running Exchange 2003 on Windows 2003.