Normally you would get a FolderClosedException to indicate this. Because of the place where the error is being
detected, that requires special handling. I fixed that problem for IMAP some time ago, but I didn't fix it for POP3. :-(
It should be fixable; contact me at firstname.lastname@example.org if you want to try the fix when I have it available.
In the mean time I think you're stuck catching the EOFException.