Don't worry! It's only stuff...

# view mailqueue
mailq
 
# view email count in mailqueue
mailq | egrep '^--'
 
# delete singel mailqueue
postsuper -d ID
 
# delete all mailqueues
postsuper -d ALL
 
# send waiting messages
postfix flush
 
# Links
http://www.huschi.net/4_277_de-postfix-mail-queue-bearbeiten.html