What are frozen emails?

Messages are frozen when the email server has determined it cannot do anything to deliver the message and they time frozen emails created on the server and it caused problems like email queue because of that genuine emails also not able to deliver in time.

We can set a cronjob to delete frozen emails once in a day if your server facing heavy frozen email issues on daily basis or use the single command mentioned in the following thread to remove frozen emails from the server but make sure that you are logged in as a root user.

Kindly refer the following post to delete the Frozen emails

How to delete the Frozen emails

Note: Frozen messages really shouldn’t be a problem on most systems. They are often just spam messages that can’t get properly delivered.