This article will guide you on use different features available in the #WHM Mail Queue Manager. Basically, the #Mail #Queue Manager feature in WHM is a handy tool that allows us to view, delete, and attempt to deliver queued emails that have not yet left the server.
Postfix is a free and open-source mail transfer agent (#MTA) that routes and delivers electronic mail.
postfix flush helps to Flush queued mail.
This command will attempt to redeliver all queued mail. Use the command sparingly, multiple flushes will impact the overall performance of your mail server
To check my mail queue in cPanel:
i. Log into WHM.
ii. Go to Main >> Email >> Mail Queue Manager.
iii. You can click on the message to see the details.