On certain occasions enabling the Dovecot's mail server to debug mode is necessary to find answers to indexes, authentication, and inbox issues.
This how-to provides information on how to enable all of the above debug contexts.
1. Log in to the server via SSH as root.
2. Open the Dovecot's main configuration file with your favorite text editor, which is located in "/etc/dovecot/dovecot.conf
3. Enable the following settings by uncommenting the directive and configuring the following:
auth_verbose = yes
auth_verbose_passwords = no
auth_debug = yes
auth_debug_passwords = yes
mail_debug = yes
verbose_ssl = yes
4. Make sure to save the changes.
5. Restart the Dovecot service by executing the following command:
Once the above steps have been performed, you can see debug entries within the "/var/log/maillog" file, for example, login debug:
Sep 2 12:07:57 cptest.local dovecot: auth: dict(email@example.com,126.96.36.199): Password mismatch (given password: REDACTED_NOPASS)
Sep 2 12:07:57 cptest.local dovecot: auth: Debug: dict(firstname.lastname@example.org,188.8.131.52): CRYPT(REDACTED_NOPASS) != '$6$$ZsNQwThU4RYXrLfrqpyXem27D.8mJKfjGkAVojS0.S/LJVTHqRhqKr8GjDNo7oaP.FLmyjtIypj8s6sKx3BxO0'