If you experience email delivery issues on your VPS server, you can troubleshoot the problem within WHM. A Mail Troubleshooter tool is included in WHM, which traces the route an email takes when sent to a provided email address, allowing you to pinpoint the problem.
Log in to WHM and enter “Mail Troubleshooter” in the search box. Click Mail Troubleshooter to proceed.
On the Mail Troubleshooter page, enter an email address in the Email to trace text box, then click Submit.
The trace will begin. If you do not receive any error messages, the issue is most likely due to an email client configuration problem, rather than an issue with the server.
If you do receive error messages, explore the issue reported to restore email service.
If you notice any problems or if you need any help, please open a new support ticket from your HostPapa Dashboard. More details on how to open a support ticket can be found here.