So hotmail stopped popping to thunderbird the other day. The solution I found is:-
1. Ask thunderbird to create a new email account (not a web mail just a basic email account)
2. Put in your hotmail address, set the pop3 to pop3.live.com
3. In the server settings go to security settings and click the SSL box (make use the use secure auth box is NOT clicked). This will game the portto 995.
4. Restart thunderbird