[Dovecot] Book on Postfix/Dovecot or Postfix/Dovecot/Clam/Spam Assassin?

I'm looking for a book on Postfix/Dovecot or Postfix/Dovecot/Clam/Spam Assassin

The blog posts and the mini-HowTo's I am reading lack the detail to be useful to me (due to my own ignorance).

Amazon does not list any books for sale. There are some hits when searching for Dovecot, but I expect them to be one section with the quality of a blog post or mini-HowTo. (I have two books on Red Hat and Fedora administration, and the discussions don't meet the quality of a blog post).

Does anyone know of a book on Postfix/Dovecot or Postfix/Dovecot/Clam/Spam Assassin?

If there are no books with a structured treatment, then O'Reilly is always looking for authors: http://oreilly.com/oreilly/author/intro.csp.