เมื่อ Qmail เกิดปัญหา:


alert: cannot start: unable to open mutex


แก้ด้วย:


mkdir /usr/local/psa/qmail/queue/lock
touch /usr/local/psa/qmail/queue/lock/sendmutex
chown qmails:qmail  /usr/local/psa/qmail/queue/lock/sendmutex
chown qmails:qmail  /usr/local/psa/qmail/queue/lock/
chmod 777 /usr/local/psa/qmail/queue/lock