Overloaded Postfix Mail Queue

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http://www.cyberciti.biz/tips/howto-postfix-flush-mail-queue.html

Copied here as it is just so useful!

Postfix Flush the Mail Queue

by VIVEK GITE on OCTOBER 25, 2007 · 12 COMMENTS

Traditionally you use the "sendmail -q" command to flush mail queue under Sendmail MTA. Under Postfix MTA, just enter the following command to flush the mail queue:
# postfix flush
OR
# postfix -f

To see mail queue, enter:
# mailq

To remove all mail from the queue, enter:
# postsuper -d ALL

To remove all mails in the deferred queue, enter:
# postsuper -d ALL deferred

postfix-delete.pl script

Following script deletes all mail from the mailq which matches the regular expression specified as the first argument (Credit: ??? - I found it on old good newsgroup)

#!/usr/bin/perl   $REGEXP = shift || die "no email-adress given (regexp-style, e.g. bl.*\@yahoo.com)!";   @data = qx; for (@data) {   if (/^(\w+)(\*|\!)?\s/) {      $queue_id = $1;   }   if($queue_id) {     if (/$REGEXP/i) {       $Q{$queue_id} = 1;       $queue_id = "";     }   } }   #open(POSTSUPER,"|cat") || die "couldn't open postsuper" ; open(POSTSUPER,"|postsuper -d -") || die "couldn't open postsuper" ;   foreach (keys %Q) {   print POSTSUPER "$_\n"; }; close(POSTSUPER);  

For example, delete all queued messages from or to the domain called fackspamdomain.com, enter:
./postfix-delete.pl fackspamdomain.com
Delete all queued messages that contain the word "xyz" in the e-mail address:
./postfix-delete.pl xyz