I've seen your article on this subject, thanks. My wife's account, dheuvel, has this problem. I changed the password about ten hours ago, and no change. Can you please lift the ban on her account.
I've checked her login using MalwareBytes (and it's already under guardianship of Eset antivirus) and her account is clean.
Is it possible this occurred because she downloaded a lot of accumulated email (about 3,500 items) in one hit? She normally reads on her ipad, but downloads onto the main computer only occasionally.
Regards and thanks,