Root email notifications not being delivered

Symptoms

The root email notifications are not delivered to the server's admin contact email address, and running a trace to the root account gives output similar to the following.

[root@server ~]cPs# exim -bt root
root@server.hostname.tld is undeliverable: The mail server could not deliver mail to root@server.hostname.tld.  The account or domain may not exist, they may be blacklisted, or missing the proper dns entries.

Description

The issue is typically caused by the root forwarder not being configured and/or the server's hostname not having an entry within /etc/localdomains.

Workaround

1. Log into WHM as the ‘root’ user.
2. Navigate to "Home / Server Contacts / Email System Mail Preferences."
3. Scroll down to the root forwarder.
4. Enter the desired address for the root forwarder.
5. Click the "Update" button for the root forwarder.
6. Access the server's command line as the 'root' user via SSH or "Terminal" in WHM.
7. Open /etc/localdomains in your preferred text editor.
8. Ensure that the first entry is the server's hostname.
9. Save the changes and exit the text editor.

Additional resources

Edit System Mail Preferences