Is port 25 blocked on my cable?

[MrGecko]

Warning: fsockopen() [function.fsockopen]: unable to connect to alt2.gmail-smtp-in.l.google.com:25 (Operation timed out)
Am I getting that because my cable company is blocking port 25?

[supermanjnk]

I know some Cable companies block outgoing SMTP so that people can't just set up mail servers all over the place. Most of the time you have to use your cable company's SMTP server

[MrGecko]

I am trying to verify email addresses by sending an message to the server at an address to see if it accepts it as shown in a tutorial. I guess I can just check to see if it has MX records or not.