Hi,
# clean up postmaster 00 30 * * * root /usr/bin/find /var/qmail/maildirs/postmaster@telbit.pt/Maildir/new -type f -print0 | xargs -0 -n 50 rm
If that is the actual crontab entry, then it is not valid, as the second column is the hour (there is no hour 30). You probably want this:
30 00 * * * root /usr/bin/find /var/qmail/maildirs/postmaster@telbit.pt/Maildir/new -type f -print0 | xargs -0 -n 50 rm
I'm getting old, i guess :(
Warm regards