Having problems sending emails with Comcast? Read this:

http://www.pdxtc.com/wpblog/technology-articles/cant-send-mail-using-comcast/

I was having problems with my simplemachines forum and my home outlook client.  It seems that Comcast is quietly shutting down port 25 and moving to 587 for smtp traffic.  Definitely look into it if you are having problems.

My error was this in smf (or simple machines forum):
Could not connect to SMTP host: 10060 : A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.

and this:
2: fsockopen() [<a href=’function.fsockopen’>function.fsockopen</a>]: unable to connect to smtp.comcast.net:25 (A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.