Before starting on The Book of IMAP by Peer Heinlein and Peer Hartleben, you'd better have a very good understanding of e-mail, and I recommend you at least have some experience with IMAP, or you'll probably close the book after a few pages only. I got the impression that the publisher dropped the original manuscript on the floor and upon gathering it up, they mixed up the order of the material. The book starts off with protocols and terms, moves into load distribution via load balancers, round robin DNS, IMAP proxies, selection of file systems for IMAP servers, Webmail clients and IMAP migration before starting on the IMAP servers proper! A beginner will find that very hard to follow and digest. The book is full of valuable information on the Courier and Cyrus IMAP servers, and the authors have collected plenty of tips on those programs. However, there is little information about interaction with client programs and with e-mail servers, so if you've never set up an e-mail server with an IMAP (or POP3) server, I think it will be difficult to follow. The (unofficial) Web site of The Book of IMAP has little additional information (at the time of this writing), but that may change.