I have 3 Hotmail accounts which i monitor through Mailwasher and then use OE 6 to send and receive.
I've just had OE and Mailwasher lock up on me because it tells me there is a message called "Don't let your MSN Hotmail account freeze up!" in the mail box which may have been removed.
Thinking this could be some sort of clever e-mail that locks up your account I went in through the website and removed the message from all 3 accounts. Each time if i tried to open the message (from Hotmail by the way) it said the message didn't exist!