original title: I am receiving the error message below when trying to send e-mail via Windows Live.  I can receive e-mail, but can not send them, even to myself.

An unknown error has occurred.

Subject ''
Server Error: 554
Server Response: 554 omta01.westchester.pa.mail.comcast.net comcast Port 25 not allowed - http://customer.comcast.com/help-and-support/internet/email-client-programs-with-xfinity-email/
Server: 'smtp.comcast.net'
Windows Live Mail Error ID: 0x800CCC6F
Protocol: SMTP
Port: 25
Secure(SSL): No