This article is for cPanel Accounts. Determine where your account is with this guide.
Most local Internet Service Providers [ISPs] block port 25 for outgoing mail traffic to try and combat spam being sent through their network connections. For this reason the default outgoing WestHost port is 2525, so we suggest always using that port for your SMTP or outgoing server settings.
If you want to test to see whether port 25 is being blocked for you locally, test with this online tool: http://port25.icannotconnect.com/
Please note: telnet is disabled on Windows 7 by default and you may need to enable it on your computer.