CommuniGate Pro Mail Server

With the Internet continuing to grow by leaps and bounds and more people becoming exposed to it, a proliferation of new network and Internet-specific software is coming out, giving potential buyers a confusing array of software from which to choose. Free web hosting and “free e-mail for life” sites now number in the hundreds at least, and seem to be multiplying daily. Most companies now require Internet access, including at least a corporate web site and employee e-mail. Many sites are either running NT and the Microsoft Solution for mail and web services, or using UNIX systems such as Sendmail along with a POP3 or IMAP server. After all, Sendmail has been with us for ages, and it's something most UNIX administrators are familiar with. MS Exchange and Sendmail pretty much dominate most mail-server markets today, so why change? Stalker Software (http://www.stalker.com/), a company with a background in Macintoshes and mail software, intends to change all that with their CommuniGate Pro (CGP) mail server.

While Stalker appears to have their work cut out for them, they are also off to a good start. The company has received numerous awards for the CGP product, ranging from UNIX Review to the Linux World Editor's Choice. Not being content to blindly listen to others' reviews, I sat down to install CGP on my mail server running Red Hat 6.0. If you don't use UNIX for your mail server, they've got you covered there as well. CGP runs on a broad range of platforms, including most UNIX variants, Mac OS X Server and Windows, and is currently in version 3.1 as of this writing, with a 3.2 beta available for testing.

Installation is fairly straightforward for all versions I've tested, those being Red Hat 5.2 and 6.0 (RPM and tgz) and Windows NT 4 Server. For review purposes, I'll be concentrating on the Linux version, although everything aside from the installation itself should apply across all platforms. The install script adds its init scripts for startup and shutdown, replaces the mail binary with a CGP-compatible version, and you're off and running. We're not done yet, though. Stalker realizes many users will be migrating from another system, such as an IMAP or POP server. CGP/Stalker provides some simple tools to import users and mailboxes, which can mean the difference between a relatively quick and easy installation, or an all-day (or longer) process for companies with hundreds or thousands of users. You can, of course, also add users manually. Users can even be imported/created via a simple text file, which can easily be made from your password file.

Once the server is up and running, administration is normally handled via a web interface. For the more security-conscious, a nice feature is that with versions 3.1 and later, this can be done via an SSL web connection. For the truly stubborn, it can also be configured via text files. While I am not a fan of web interfaces, this one is quite good. On-line HTML help is part of the system and just a click away. Earlier versions had pointed to the Stalker web site, but now all documentation is available locally. Mail domains and routing, access rules, log levels and all configuration is easily done. It does take a while to become used to getting around the interface the way it's laid out, as well as learn some of their terms, so the help does come in handy for the more unusual features.

After the initial configuration is done, you have a large number of choices to make. For the most part, the defaults may be acceptable and are enough to get the system up and running, but the fact that this is certainly no trimmed-down mail server becomes readily apparent once you spend some time in the Admin screen. You have quite a few options, such as allowing web-based mail access, using SSL, allowing IMAP, POP, ACAP and PWD clients, maximum number of connections allowed, log rotation and levels, mailing-list configuration, blacklisted domains and more. Most of these will already be familiar to mail administrators, and others may be new to some. Administrators may also limit system resources, message size, allowable services, and web space on a per user/list or per domain basis, as well as setting new defaults.

A very nice feature is server-wide rules, which allow us to bid adieu to fighting with procmail recipes. Or perhaps not—the rules also allow the execution of external scripts, if you so choose. They allow anything from simple redirections to auto-replies using the sender's information inside of the reply message.

An LDAP module is included as part of CGP. CGP also provides its own web server module, allowing users to create their own web sites and update them via the Web Mail interface. The list goes on and on—after using CGP for several months, I'm sure there are yet more pleasant surprises to be discovered.