Updated: 28 September 2026 · Applies to: cPanel & WHM 138 (WHM, root access)
Some internet providers block outgoing port 25, so mail programs cannot connect to your server on it. cPanel can run the Exim mail server on an extra port as well.
Steps
- Log in to WHM as root (
https://your-server:2087). - Open Service Configuration › Service Manager.
- Tick the Exim entry for another port (the default extra port is
26), change the port number if you want, and tick Monitor. - Click Save.
Also open the port in your firewall. Mail programs can then use it as the outgoing (SMTP) port.
Tip: Mail programs normally use port 587 (STARTTLS) or 465 (SSL) for sending, which are rarely blocked. Try those before adding another port.
