[Dovecot] both passwd-file and MySQL

Hello all!

Wondering if it is possible to use a flat passwd-file for some domains and for some other a MySQL-database for queries?

All of our domains are handled by

passdb { args = /etc/dovecot/passwd driver = passwd-file } userdb { args = /etc/dovecot/passwd driver = passwd-file }

Can one use MySQL in addition for another domain?

Greetings

Andreas