On Mon, 3 Aug 2020, Kishore Potnuru wrote:

> ===============
> Jul 28 11:14:23 auth: Fatal: Master passdb can't have pass=yes if there are
> no passdbs
> Jul 28 11:14:23 master: Error: service(auth): command startup failed,
> throttling
> ===============
>
> after the above error, I have commented "pass=yes" in production1 (old
> server) server, then I see the below error.
>
> ================
> Jul 28 11:17:10 auth: Fatal: No passdbs specified in configuration file.
> PLAIN mechanism needs one
> Jul 28 11:17:10 master: Error: service(auth): command startup failed,
> throttling
> ===============
>
> =========================================
> My old server dovecot.conf (production1):
> =========================================
>
> passdb {
>        args = /etc/dovecot/passwd
>        driver = passwd-file
>        master = yes
>        pass = yes
>        }

My interpretation of your error messages is you need 2 sets of credentials:
regular users and master users.  You've only supplied master passwords.
You'll need

        # Contains master users credentials
        passdb {
                args = /etc/dovecot/master-passwd
                driver = passwd-file
                master = yes
                pass = yes
        }

        # Contains regular user credentials
        passdb {
                args = /etc/dovecot/passwd
                driver = passwd-file
        }

Joseph Tam <jtam.home@gmail.com>