How To Change SMTP Port On VPS OR Dedicated Server

With just a few clicks, servers deployed with cPanel can have their SMTP configuration changed to an extra port. For ISPs who block port 25, it is helpful.

Simply login to your server via WHM as root. Access options Service Configuration » Service Manager & look for exim on another port. Check both the options as in snapshot below & enter additional port number on which SMTP should work.

Click on Save & open the port in your server firewall. Try performing a telnet to server IP on additional SMTP port & check if you can connect.