messages sitting in the sendmail queue

Hi there,
I have Fedora 6 machine with sendmail 8.13.8.
Somehow about 20,000 messages are sitting in the queue /var/spool/
mqueue and not being delivered.
Maillog messages:
sendmail: grew Worklist for /var/spool/mqueue to 2000 then
subsequently to 12000
sm-msp-queue: starting daemon(8.13.8): queueing@01:00:00
How ever if I send a message it sends it right away.
Thanks a lot, Calin