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Enterprise Functionality for the SMB

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Kerio Mail Server: Secure and easily managed e-mail and groupware server designed for SMBs.

SMBs seeking a secure e-mail and groupware server that is easily managed need look no further than Kerio Mail Server.

Positioned somewhere between the ISP mail server and an in-house behemoth (Microsoft Exchange) are independent e-mail server products that provide the accessibility of a public service with the security of a private system — without the administrative overhead.

This is where’s Kerio Mail Server 6 competes. And with its many features at a reasonable price, it competes very well.

In fact, at least for small and midsize businesses (SMBs), Kerio Mail Server positions itself as an alternative to Microsoft’s ubiquitous e-mail and groupware server. We tested its new and enhanced groupware features (e-mail, calendaring, and task management) and found them to perform on a par with Microsoft Exchange.

In addition to its own Web Mail client, Kerio supports Microsoft Outlook and Entourage (on Apple) for e-mail and groupware. For Outlook, it requires the Kerio Outlook Connector be installed on each client. The Outlook support requires online connection to the Kerio server, otherwise another product, Kerio Synchronization plug-in, is required to provide local Outlook storage for offline operation. Despite these hitches, the groupware features in Kerio Mail Server are robust and responsive, and the Kerio Web Mail client works under Linux and Apple as well as Windows. For those considering moving from Microsoft Exchange, Kerio sweetens the bait with a free and slick migration tool.

Easy Installation and Administration

Kerio Mail Server has a small footprint. Deerfield recommends a 1 GHz processor, 512 MB of RAM, and 120 GB disk space. For reasons of compatibility and resource use, it is probably best operated on a dedicated server. In a crowded field, Kerio stands out for its attention to detail; for example, documentation and how it goes about explaining itself. This also pays off in a wizard that smoothly handles installation and configuration. Kerio Mail Server supports many protocols (e.g., POP3, SMTP, IMAP4, WAP, and Blackberry) as well as a number of connection configurations, including, dial-up, LAN, and leased-line. The support for relatively sophisticated scheduling of e-mail operations for dial-up connections may be particularly useful.

In a crowded field, Kerio stands out for its attention to detail; for example, documentation and how it goes about explaining itself. This also pays off in a wizard that smoothly handles installation and configuration.

The Kerio server can be administered from either the Administration Console (generally operated on the server machine) or remotely with the Web Administration feature. Both are utilitarian in design, offer some Wizard support for common tasks, and get the job done easily for an administrator only moderately familiar with e-mail and network operation. A number of logs (Config, Mail, Security, Warning, Error, Spam, and Debug) provide information and statistics on all areas of operation. In general, the relative simplicity of administration also reflects fewer options and customization capabilities.

One of the things we liked most about Kerio were features that would be expected for very large installations, for example, the ability to synchronize with Microsoft Active Directory and Apple Open Directory — not just download and update, but transparently connect with and integrate information. This simplifies administration, especially in larger organizations where Active or Open directory are likely to be in use. Kerio has a template system for entering standardized information for blocks of new users. All of this greatly simplifies and speeds-up the onerous task of user management.

On the Defense

Over the years, Kerio has been ahead of the curve in matters of security, although it is difficult for a smaller independent company to deal with global problems like spam and e-mail viruses. Kerio has taken the sensible road of buying and not building much of its security. In a partnership with McAfee, Kerio offers a version of the server with McAfee anti-virus built in.

Alternatively, many other anti-virus products can be used as plug-ins — even in combination with McAfee. Its main spam fighter is the open-source SpamAssassin. Kerio bolsters its defense with a solid implementation of e-mail encryption, which can more easily be controlled within a corporate e-mail system. It also adds MAPS and ORDB blacklisting databases, and authentication procedures through Cram-MD5, Digest-MD5, Kerberos, and NTLM. To regulate the server e-mail traffic, there are relay controls (who can or can’t relay messages), maximum limits on messages from one source, and other tricks of the defense trade. Add all this together, and Kerio ranks among the best mail servers for security.

There are slicker groupware products and more powerful email servers, but the price to pay (beyond the dollar amount) is complexity. Kerio Mail Server delivers what it promises (besides e-mail), which is good performance over a range of e-mail and groupware features in an easy-to-manage package. It makes for an attractive product for organizations with smaller networks or those wishing to simplify their email management.

Pros: Multiplatform (Windows, Linux, and Mac OS X) support for e-mail and groupware features; Mailing list support.

Cons: Firewall support is limited (Kerio sells a separate firewall product).

Reviewed by: Nelson King
Original Review Date: 03/08/2006
Original Review Version: 6.1.2

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