Kerio MailServer 6.5 review

Microsoft’s Exchange may be the “you won’t be fired for buying it” choice for SMEs, but there are number of mail server choices available. With this release, Kerio MailServer becomes our favoured option, with numerous advantages over both Exchange and rivals like Gordano.

We’re impressed by Kerio’s ability to support a wide range of clients (more on that later), but it can also run under a wide variety of operating systems. From Windows 2000 Professional SP4 to 2003 Server to Vista Business, from Red Hat Linux to SUSE Linux to Mac OS X 10.4 and 10.5 – everything’s covered. Its only fault is that 64-bit versions of Windows and Linux aren’t supported.

We installed the Windows version on a desktop PC equipped with an AMD Athlon 64 X2 5000+ and 2GB of RAM, running Vista Business. We created several test users using the server’s own internal database for security, although we could just as easily have imported users from Active Directory. It’s possible to combine both methods, which can be useful when some users don’t need Active Directory accounts.

We tested the server using a program that sent several hundred messages to each user using plain text and HTML. We also included some spam and the EICAR test virus in various attachments. Everything went without a hitch.

Antivirus duties are handled by McAfee Anti-Virus, which is provided as standard. A second antivirus engine can be added if required, and products from suppliers such as Grisoft, NOD32 and Symantec are supported as well as the popular open-source ClamAV. Email is scanned in both directions and, to prevent an infected system from spreading a virus throughout the LAN, internal mail is also scanned. Infected mail may be disinfected or quarantined as required.

SpamAssassin is available to filter out unwanted mail, and real-time blacklist and Bayesian analysis options are also available. Other measures include both Microsoft’s Caller ID and Sender Policy Framework options.

The system can be administered through the local administration interface or remotely using the supplied software. In both cases the administrator can configure and monitor all aspects of the server’s operation. Email archives are becoming increasingly important, and Kerio automatically archives all messages for later review.

The new CalDAV feature allows Apple iCal users to share their calendar data with other users. Apple’s iCal client won’t play nicely with Microsoft Exchange, and while there are several workarounds available, this feature simplifies things and allows Mac users to use the collaborative features available to Windows users without having to resort to the web-based client or use Entourage.

Kerio has also extended the Outlook Connect feature. The previous version allowed the user to use Outlook as a client while connected to the server, but the new offline feature offers the chance to work with Outlook without being connected; Outlook will synchronise itself when the user connects to the server again. This is of great interest to users who need to work with tasks and arrange appointments while on the move.

Both Gordano’s Messaging suite and Kerio’s MailServer offer viable alternatives to Microsoft’s Exchange Server in the SME market. Neither one requires a Windows Server licence, and they will both run happily on quite modest hardware. Gordano will scale further than Kerio’s product, but it comes with a higher price.

Kerio MailServer’s support for mobile devices such as smartphones running Windows Mobile allows users to keep in touch even without an internet connection. This, combined with the price, should be enough to tempt even the most Microsoft-loving IT manager.