Stalker’s CommuniGate Pro is a Linux application designed as a network-wide mail server. The product has an amazing collection of supported features and abilities, making it one of the most talented mail servers available on any platform, let alone Linux. A quick glance through the alphabet soup of supported protocols gives you an idea of CommuniGate Pro’s flexibility. There’s support for all the standard mail protocols (POP3 and IMAP4), Internet mail exchange through SMTP and ESMTP, central directory and LDAP support, as well as antispam features!

We installed CommuniGate Pro on a RedHat Linux system for testing. Installing CommuniGate Pro is through RPM, and the installation routine create a bunch of other scripts that take care of routine tasks for you. As part of the installation, CommuniGate Pro replaces standard mail handlers such as sendmail binaries with its own versions, as well as providing startup and shutdown scripts. The interface to CommuniGate Pro is through HTML, allowing any Web browser to configure the software from any platform. Remote administration is also supported through CLI and SMTP. Using the Web interface (you don’t need to have Web server software running in order to use the HTML interface) you can configure CommuniGate Pro quite quickly, although the task of setting up mailboxes and aliases can take a while for a larger company. The Web connection is protected by SSL, but for those who dislike Web interfaces of any kind, standard ASCII editors can be used to modify the configuration files. On-line help is accessible through the Web interface and is quite good. Setting up a site with 100 users and a bunch of virtual routes took a couple of hours, but the process quickly becomes routine.

Administration tasks are light because scripts handle most of the tasks for you, including logging and log file handling. An administrator can monitor the behavior of CommuniGate Pro, including mail transfers and connection behavior, as well as observer the flow of mail to users. The anti-spam measures are good, although there will always be some mail that sneaks through. You can block mail by a number of mechanisms, including source names, domains, or IP addresses. Administrators can set up multiple mailboxes per user as well as shared mailboxes, and allow multiple domains to be handled by a single installation of CommuniGate Pro.

The default setup provided with CommuniGate Pro will suffice for most installations, but you can modify practically every aspect of the mail server and clients. You can establish server rules that dictate who CommuniGate Pro will behave and how it is accessed, which allows you to set policies and stick with them. You can invoke or disable scripts for mail handling, as well as executing external scripts (such as backup routines). The list of customizable aspects can be truly staggering, and you can apply completely different sets based on a network-wide, domain-specific or even user-specific approach.

The default client access method for CommuniGate Pro is through the Web, and while Web-based mail clients tend to get a lot of complaints they are becoming more common and useful. You aren’t stuck with the Web mail client, of course. You can use practically any client that talks one of the protocols provided by CommuniGate Pro. After playing with the Web interface for a few days, we were struck by the ability to modify just about every aspect of the system: how many mail messages appear on the screen at once, how mail is displayed, setting up hidden and common mailboxes, and so on. If you do use the Web interface you’re still stuck with the browser buttons for many tasks, and there are a few quirks where the order of messages gets jumbled up and read mail is mixed with unread, but on the whole the Web interface works surprisingly well. We suspect most users will be using commercial mail packages, through, and CommuniGate Pro works well with all of them.

We tried CommuniGate Pro with a 50 user license and bombarded the system with tons of mail, including lots of bogus addresses and stuff we would treat as spam. We kept recycling the messages, so we put through over 1,000 pieces of mail per hour. The CommuniGate Pro server kept up with the load without a problem, although our mailboxes and log files grew quite large! We had no problem at all with the CommuniGate Pro server of Web clients, as they continued to work throughout the one-week testing period without a crash. CommuniGate Pro is not an inexpensive mail handler, but compared to packages like Microsoft’s Exchange Server, it is a bargain. The flexibility of the package is wide, but be prepared to spend a while getting it set up properly. The software runs on a wide number of platforms, so it’s likely there is a version for your network.

CommuniGate Pro
$499 50 users
Stalker Software
655 Redwood Highway, Suite 275
Mill Valley
California, 94941
800 262 4722
415 383 7164
415 383 7461 fax

Summary: A surprisingly powerful and flexible mail server and client with tons of configurability and excellent robustness.