Basic Mail Server Security
Ipswitch iMail Server
SuSE Linux OpenExchange
What to look for
A must when contemplating a Sendmail environment is to purchase a copy of the O'Reilly -Bat" book (Building, Installing, and Administering Sendmail by Bryan Costales with Eric Allman) -- this is a comprehensive guide to pretty much anything one needs to know about Sendmail and is extremely easy to follow.
One thing that Sendmail has never been known for is its ease of configuration (particularly the virtually cryptographic Sendmail.cf file), while it is simple to get up and running fine tuning and tweaking it can leave one a little wobbly in the knees let alone in the head. Don't worry if you need help or extra features and are willing to pay for them, the developers of the freeware version of Sendmail have a commercial company, see www.sendmail.com.
A myriad of open-source plug-in applications are available for managing and monitoring Sendmail. A very popular tool for those with a GUI bend on Linux is Webmin. I ran up a server with Slackware 10.0, Sendmail and installed Webmin for the purposes of this review. Webmin not only manages Sendmail but also many other aspects of Linux applications and their associated configuration. And the best bit is the author of Webmin comes from Melbourne. Ok so it is a bit of a soft option for most hardcore Linux nuts out there who prefer the CLI but some people must eventually grow up and realise not everyone is a ubergeek super programmer who live, eat and breath in vi commands. In that vein if you are looking for a laugh then check out www.ubergeek.tv.
It is a very reliable, robust, scalable solution when combined with Webmin, and a decent Linux distribution should give the owner many years of faithful service. If you haven't tried it, get the book and give it a spin in a test environment -- you should be pleasantly surprised.
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