The static master username will be expanded to `DOVECOT_MASTER_USER@mailcow.local`.
To login as `test@example.org` this would equal to `test@example.org*mymasteruser@mailcow.local` with the specified password above.
A login to SOGo is not possible with this username. A click-to-login function for SOGo is available for admins as described [here](https://mailcow.github.io/mailcow-dockerized-docs/debug-admin_login_sogo/)