Don't know where Amavisd config file is? check this tutorial: Locations of configuration and log files of mojor components.
To turn on debug mode in Dovecot, please update below parameter in Dovecot
config file dovecot.conf:
mail_debug = yes
Restart Dovecot service.
If you need authentication and password related debug message, turn on related settings and restart dovecot service.
auth_verbose = yes
auth_debug = yes
auth_debug_passwords = yes
auth_verbose_passwords = yes
If you found something wrong in this document, please do contact us to fix it.
This tutorial is published under a CC BY-ND 3.0 license.