I have 2x 3rd party email accounts mapped to Windows Live Mail:

1) NWlink.com (thru Infinity Internet), POP3 setup

2) Gmail.com, IMAP Setup

I can receive messages fine. 

Earlier this year WLM's ability to send just stopped.  I didn't change any settings prior to this happening.

I did some trouble shooting some months ago with no success.

Ideas anyone?