by Tom Uijldert, in July 2006 (article #392)
Nothing remarkable about sending messages to and fro, relying on some distribution system that gets those letters to their destinations.
So unremarkable that you don't even notice how it sneaks up on you and suddenly (usually when the email service is down), you realise how dependent you've become on this technology - like electricity, like a telephone - and what an important part of your life it has become.
A good part of the day in the office now includes handling emails. And though there may be the odd “recreational” mail from the local fun-list in between, most of this handling is serious and productive work. It is considered normal to have your email client continuously active during office hours.
And even in private life, if you haven't opened your private mailbox for more than a week, people start asking questions like “didn't you get my email?“.
Also, when this realisation dawns on a small business or office, more questions follow, like: “Should we really be leaving the handling of such company-sensitive data up to our provider?”.
A scenario along these lines must've crossed the minds of the authors when thinking up the concept of this book.
Well, if you're that local sysadmin, you may want to read this.
The setup of the book is simple:
and describe in detail how to install these packages, configure them and set them up such that it all cooperates to handle email in concert and you have your book.
So what does it give the sysadmin?
A real timesaver therefore.
There is a big question-mark on who this book is written for. According the back-cover: “...'unofficial' sysadmins in small businesses...”. Because you immediately get on the narrow path of what these 'unofficial' sysadmins might actually be capable of doing. For me, such persons may well be able to follow a recipe on how to install a package, but building from source? Yet, here and there, the reader is expected to do this.
The book is undoubtedly very practical. Like in chapter 1 they immediately sum up a list of reasons why one might want to set up their own email-handling system in the first place. I particularly liked the paragraph on Sizing, stating that the old 'back-of-the-envelope' method would be more than precise enough to estimate your needs. “ hear”. The description of DNS though, is a but thin. Where stuff like SMTP is at least still handled at a rudimentary level ('what's it for?'), the paragraph on DNS merely states that the reader is supposed to be familiar with DNS and just dives into the details. That is inconsistent and a problem. Does the 'unofficial' sysadmin not know his SMTP but is he fluent in DNS? Doubtful.
It is the one issue I have with this book but I admit that it is a tricky one. How much does this unofficial sysadmin know? For that reason, I think that the authors might've given chapter 1 a bit more attention and possibly elaborate a bit more on the inner workings of such a system.
Apart from this, the subsequent chapters just march along, setting up the system piece-by-piece in a very experienced manner. This is proven by having gems like entire paragraphs devoted to Configuration debugging and remarks like “...when you do this, don't forget that or you'll spend days finding what the problem is...“.
It's fairly complete too. The last chapter, dealing with backups, is another gem. You may not want to deploy the scheme presented here but at least a complete overview is given on what needs to be backed up. And that is always useful (the stuff on version controlling your configuration files is a bit too much for my taste, but hey, better safe than sorry).
Following this book, you'll get a pretty decent and complete email handling system, including something like webmail - a must in corporate life nowadays - and very elaborate filtering possibilities, including spam-detection and virus-control.
In the meantime, if you need to set up an email system and are looking for the quickest way to go, this book must be it.
About the author
Tom is a member of the Dutch linuxfocus team and has been using email since the invention of domain addressing.
<tom.uijldert /at/ linuxfocus.org>