Split from this thread.

Error message received after doing what you suggested...

Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity.

Subject 'test'
Server: 'mail.twc.com'
Windows Live Mail Error ID: 0x800CCC0F
Protocol: SMTP
Port: 587
Secure(SSL): Yes
Socket Error: 10053