user = mailuser
 password = fLxsWdf5ABLqwhZr
 hosts = 127.0.0.1
 dbname = mailserver
 query = SELECT 1 FROM virtual_users WHERE email='%s'

virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf

postmap -qv dave@example.co.za mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf

fatal: open database dave@example.co.za.db: No such file or directory