How to enable Dovecot's debug log options

Question

How can I enable Dovecot's debug log options?

Answer

On certain occasions, enabling debug mode in Dovecot's mail server is necessary to find answers to indexes, authentication, or inbox issues. The following provides information on enabling further debug logging in Dovecot.

1. Log in to the server via SSH as root.
2. Open Dovecot's main configuration file, which is located in /etc/dovecot/dovecot.conf, with your favorite text editor.

3. Enable the following settings by adding the following directives:

   Dovecot 2.3

   Note: The following instructions are for cPanel 130 and below.

   CONFIG_TEXT: auth_verbose = yes
   auth_verbose_passwords = no
   auth_debug = yes
   auth_debug_passwords = yes
   mail_debug = yes
   verbose_ssl = yes

   Dovecot 2.4

   Note: The following instructions are for cPanel 132+.

   CONFIG_TEXT: log_debug = category=ssl category=auth
   auth_verbose = yes
   auth_verbose_passwords = no
   auth_debug_passwords = yes
   mail_debug = yes

4. Save the changes.

5. Restart the Dovecot service by executing the following command:

   # /scripts/restartsrv_dovecot

Once the above steps have been performed, you will see debug entries in the /var/log/maillog file like these:

CONFIG_TEXT: Sep 2 12:07:57 cptest.local dovecot: auth: dict(cptest@cptest.local,198.51.100.225): Password mismatch (given password: REDACTED_NOPASS)
Sep 2 12:07:57 cptest.local dovecot: auth: Debug: dict(cptest@cptest.local,198.51.100.225): CRYPT(REDACTED_NOPASS) != 'REDACTED'