[Dovecot] Authenfication on 2 databases

[LeeJaY]

Hello,

I have 2 databases MySQL. I would like to do that:

If the user does not existe in the first base, it goes in the second
database.

my configuration 

auth default {
        mechanisms = plain
        passdb sql {
                args = /etc/dovecot-sql-1.conf
        }

        passdb sql {
               args = /etc/dovecot-sql-2.conf
        }

        userdb sql {
                args = /etc/dovecot-sql-1.conf
        }

        userdb sql {
               args = /etc/dovecot-sql-2.conf
        }
}

but it don't work, my version est 1.0.alpha1

if you not understand this message, i am sorry, my english is bad