These instructions are written for RPM-based systems (RedHat, Fedora, CentOS, etc.). Instructions for DEB-based systems (Debian, Ubuntu) can be found in KB article #115980.
Please perform the following steps to recreate Qmail's queue.
All current messages will be removed from the queue and cannot be restored.
1. Stop Qmail and xinetd.
mv /var/qmail/queue /var/qmail/queue_old
3. Reinstall "psa-qmail" RPM to recreate qmail queue structure with the command:
rpm -Uvh --force psa-qmail....
4. (Optional) Reinstall "drweb-qmail" RPM if you use the Dr. Web anti-virus feature which comes with Plesk.
rpm -Uvh --force drweb-qmail....
5. Start Qmail and xinetd:
You can obtain the current "psa-qmail" RPM, "drweb-qmail" RPM, and Plesk build version by running the following commands on Linux systems:
rpm -q psa-qmail
rpm -q drweb-qmail
rpm -q psa