http://gnufreakz.wordpress.com/2010/06/08/postfix-queue-management

http://blog.gtuhl.com/2008/08/14/basic-postfix-queue-management

http://postfixmail.com/blog/index.php/manage-mail-in-the-deferred-queue/

These systems use Postfix as the MTA:

• Virtualmin
• Zimbra

postqueue -p

View a particular message:

postcat -q <messageID> | head --lines 100

grep "Nov 13 06:13:" /var/log/maillog*

grep "D233911382F9" /var/log/maillog*

• Default queue_run_delay (interval between send attempts) is 300s or 300 seconds

Attempt to send queued mail now:

postqueue -f

View a deferred message:

postcat -q 022412012A | head -40

or:

postcat /var/spool/postfix/deferred/0/022412012A

Delete all queued mail:

postsuper -d ALL