Electronic mail is a favorite topic of mine, but since you can always teach an old dog new tricks, I was pleased to receive a copy of Pro Open Source Mail authored by Curtis Smith. With a subtitle of Building an Enterprise Mail Solution, my expectations of the 400 page book were very high, as I feel quite proficient in building e-mail solutions for enterprises. :-) The book is well written and actually has most of what is needed for assembling an e-mail solution: a bit of history followed by the tools of the trade: sendmail, Dovecot as a POP3 and IMAP server, SquirrelMail for web-based mail, a bit of procmail, some ClamAV to fight off malware, and a pinch of SpamAssassin and MailScanner to get rid of the rest, followed by a drop of Mailman for generating what others might not want. Apart from two of the ingredients, I believe the author has put together the best that Open Source has to offer in the way of programs for assembling a Mail Solution. I personally would have used a different MTA, namely Exim, but that is a question of taste. Another ingredient that doesn't fit the picture is the operating system that the author chose to base his book on: Fedora Core 4 is not what I'd name an Enterprise-class base for a mail solution. Back to the subtitle: Building an Enterprise Mail Solution. The book covers all that is needed to set up e-mail for a few dozen users, maybe a hundred, but not for an multi-thousand employee enterprise. Smith leaves the complex topic of high- availability out of the picture (but he states that clearly). Monitoring, fail over, backup, user-management, and directory services (LDAP) aren't covered although they are essential for the enterprise. Enterprises mostly have a DMZ which can require several levels of internal mail routing (a complex topic), internal and external DNS, etc. Interoperability with existing or planned groupware systems is non-trivial and is a major building block in enterprise e-mail. Users in large environments often don't have real user accounts on a mail server; they are "virtual" in as much as a directory service provides the data necessary for both mail delivery and pickup. Such systems are widespread, but I missed their discussion in the book. There is much more in getting e-mail running in an enterprise than to smack a few programs onto a PC with a desktop-Linux distribution, but it may also be that I am too serious about such an undertaking. Once again. The book is good, and it is packed full of goodies. I feel the volume's subtitle to be way off target. If you are a beginning to intermediate systems administrator wanting to build an e-mail solution for a small to medium-sized environment, this book is for you. Apress have the full table of contents as well as a chapter 5 Configuring sendmail and DNS available for the interested reader.