Get the mailids of all email currently in queue:

postqueue -p|egrep “[A-F0-9]{11}”|awk ‘{print $1}’

Get the count of emails in queue:

mailq | tail -n 1


postqueue -p|egrep “[A-F0-9]{11}”|awk ‘{print $1}’|wc -l

List all message in queue:

postqueue -p

To flush the mail queue:

postqueue -f

To remove all mails from the queue:

postsuper -d ALL

To remove all mails in the deferred queue:

postsuper -d ALL deferred

To view message content in queue with id xxxxxxxxxxx

postcat -vq xxxxxxxxxxx