Free documentation for beginners about mail server basis ?

[Christophe . Andreoli]

     Hello,

I agree that the installation and configuration documentation are well
made.

But It is not really helpful for a Mail Server beginner like me. Do you
know some Documentation

that explains the whole, that is, how does a mail server work, whre the
concept are explained , other than the Qmail books ?

               thank you



          Christophe