Let’s say that you need to delete a plesk domain with email and recreate it.
1. Recording the email addresses and passwords (over ssh you can use the command /usr/local/psa/admin/bin/mail_auth_view to show addresses and passwords)
2. Making a copy or renaming of the folder /var/qmail/mailnames/domain.com to something like /var/qmail/mailnames/domain.com.BAK
3. Deletion of the Alias and addresses
4. Creating domain.com as a domain in plesk
5. Manually recreating the email addresses for domain.com under the Mail tab for the domain in plesk.
6. Moving the /var/qmail/mailnames/domain.com.BAK directory back to its original location or rename back to /var/qmail/mailnames/domain.com
7. Ensure that the owner and group of the directory is popuser:popuser by running the command (chown -R popuser:popuser /var/qmail/mailnames/domain.com)
8. Run the plesk tool to rebuild the mail handlers. (/usr/local/psa/admin/sbin/mchk –with-spam)