You will need to download and install qmHandle which you can get from
here.Next you need to stop qmail. I saw a reply saying the proper way to stop qmail was
svd -d /service/xxx
but I tried this and it didn't work so I used the following
#/etc/rc7.d/S80qmail stop
#/etc/rc7.d/S85smtpfront-qmail stop
Once qmail is stopped from the command line run
#/usr/bin/qmHandle -D
(
WARNING - this will delete
ALL the mail from both the local and remote mail queue's). Now you can restart qmail.
#/etc/rc7.d/S80qmail start
#/etc/rc7.d/S85smtpfront-qmail start
Hope that helps.
Regards Lloyd