If your receiving this error, and your able to "receive" email, then your ISP (Internet Service Provider) is blocking remote SMTP Service,
its your ISP answer to controlling spam -

Please use our TroubleShooter for Mail - select -
How to test if an ISP or Firewall is blocking SMTP
http://occsupport.com/menu/index.php?_m=troubleshooter&_a=steps&troubleshootercatid=2&parentid=0

If the problem continues, select Troubleshooter "error message: "

The specified server was found but there is no response from the server. Please verify the port and SSL information"