http://blogs.flaphead.dns2go.com/archive/2008/07/24/free-exchange-server-ebook.aspxJust discovered this blog and found a freebie ... Can't be bad. All you need to do is provide an email address you can download the 379 pdf doc that is made up from thses books: Mastering Exchange Server 2007 Chapter 2: Exchange Server Architecture ChapterenCommunityServer 2.1 SP2 (Build: 61129.2)