Dovecot book for a newbie

[techlists]

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!!