How to enable Dovecot debug logging?

Question

How to enable Dovecot debug logging?

Answer

1. Log into the server via SSH
2. Uncomment and configure the parameters in /etc/dovecot/dovecot.conf as below:

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

3. Restart Dovecot service: 

   # service dovecot restart

Note: to disable the debug logging, revert the changes: comment out the configuration parameters and restart Dovecot. Debug option "verbose_ssl = yes" doesn't work in Dovecot 2.4