Dovecot book for a newbie

Hi,

Please recommend a Dovecot book for a newbie... I have a fair amount of Linux PHP hosting experience - LAMP virtual host configurations. I'm new to BIND, Postfix, and Dovecot.

I'm running Ubuntu 20.04lts.

I have a test server almost working. Can send but not receive. Would like to understand more. I'm guessing it is a Zone (MX) / SSL / Client configuration issue.

Thanks in advance!!