[slodave]

Is your email client set up to have smtp authentication? It used to be ok for your email client to only use a username and password to check for email from a remote server. Most providers now want you to use the same username ans password in order to send email as well. This cuts down on a lot of poeple being able to spoof email addresses and send email thru servers they are not supposed to. Maybe Comcast is now requiring this?

Dave