you can add nopassword attribute to the end. See https://wiki.dovecot.org/PasswordDatabase/ExtraFields
-------- Original message --------
From: J Doe <general@nativemethods.com>
Date: 07/07/2018 02:39 (GMT+02:00)
To: dovecot@dovecot.org
Subject: Question about password field in passwd-file
Hello,