postfix queue filling up

What is filling up my postfix queue (/var/spool/postfix/deferred/)?

I had a perl script running via crontab to monitor my IP connection and send me a mail via sendmail. Now I have a huge queue of emails I keep getting. I've removed the crontab and the script. If I clear out /var/spool/postfix/deferred/, it gets repopulated. What is routing the messages here? How can I stop it?

(/var/spool/mqueue/ has always been empty)

Thanks!