How to change the mail queue lifetime in Postfix on a Plesk server

Question

In some cases, mail gets stuck for 5 days filling up the mail queue. How to change the mail queue lifetime in Postfix on a Plesk server?

Answer

By default, Postfix will keep trying to deliver mail for 5 days. The number of days is defined by the Postfix maximal_queue_lifetime parameter.

To change this limit:

1. Connect to a server via SSH.

2. Run the command below specifying the number of days. In this example, we are setting the limit to 1 day:

   # postconf -e 'maximal_queue_lifetime = 1d'

   Note: Specify 0 when mail delivery should be tried only once.

3. Verify the changes:

   # postconf | grep maximal_queue_lifetime
   maximal_queue_lifetime = 1d

   Note: Postfix service restart is not required.