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?
By default, Postfix will keep trying to deliver mail for 5 days. The number of days is defined by the Postfix
To change this limit:
Connect to a server via SSH.
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.
Verify the changes:
# postconf | grep maximal_queue_lifetime
maximal_queue_lifetime = 1d
Note: Postfix service restart is not required.