Split from this thread.

... an error message appears.

Error messages are designed to help diagnose the problem. They are not always equally helpful (Something went wrong doesn't really help much), but usually they give valuable clues to what's wrong. Please click on the error message to select it, then use right-click to copy it and paste it into your reply here.

I am having the same problem...lost ability to send

An unknown error has occurred.

Server: 'smtp.comcast.net'
Windows Live Mail Error ID: 0x80004005
Protocol: SMTP
Port: 25
Secure(SSL): Yes