About 3 weeks ago, my MS Live Mail stopped sending out my emails.  I still receive email just fine.  Other computers in the office using the same ISP are working fine.  I have double checked the SMTP protocol settings: nothing has been changed.  I have not had any new updates or installs.  

An unknown error has occurred.

Server: 'smtp.qwestoffice.net'
Windows Live Mail Error ID: 0x8007007A
Protocol: SMTP
Port: 465
Secure(SSL): Yes

I tried the alternative port 587 without success.

I'm not sure what else to try.