How to add a user as a Trusted mail user via WHM?

The Trusted mail users setting in WHM's Exim Configuration Manager allows you to specify cPanel users whose outgoing emails should bypass certain spam and routing restrictions. This is useful when a legitimate user's mail is being incorrectly filtered or when an application (like a script or CMS) needs to send email without additional Exim checks.

Step 1: Log in to WHM

Open your browser and navigate to your server's WHM login page (typically https://your-server-ip:2087 or https://hostname:2087). Log in with your root or reseller credentials.

Step 2: Open Exim Configuration Manager

In the WHM sidebar, navigate to Home » Service Configuration » Exim Configuration Manager.

Step 3: Locate the Trusted mail users Setting

Click on the Basic Editor tab (if not already selected). Use the search box or scroll to find the Trusted mail users option under the Access Lists section.

Step 4: Add the User

Click the Edit button next to the setting. In the popup box, enter the cPanel username of the user you want to trust. If adding multiple users, separate them with commas.

Step 5: Save the Setting

Click Save to close the popup, then click Save again at the bottom of the page to apply the Exim configuration changes. The system will rebuild the Exim configuration automatically.

Important Notes

• What this does: Trusted mail users are exempt from certain Exim SMTP restrictions, including sender verification checks and rate limiting rules.
• Only add users you trust: A user on this list has more relaxed email sending rules, which could be exploited if the account is compromised.
• cPanel usernames only: Enter the cPanel account username (not the email address or domain name).
• Changes take effect immediately after saving.

Troubleshooting

• Cannot find the setting: Make sure you are on the Basic Editor tab, not the Advanced Editor. Use the search box to type "Trusted mail users".
• Changes don't seem to apply: After saving, WHM rebuilds the Exim configuration. If issues persist, try restarting Exim from Home » Service Configuration » Exim Configuration Manager » Restart, or run /scripts/restartsrv_exim via SSH.
• User still having mail issues: Check the Exim mail logs at /var/log/exim_mainlog for specific error messages related to the user.

Reference: cPanel & WHM Documentation — Exim Configuration Manager