Groupware Alternatives to Microsoft Exchange

KMS authenticates user access in one of three ways: using its own internal database, by authenticating to Windows NT domain accounts, or by authenticating to AD or Apple Open Directory using Kerberos 5. Unlike MDaemon and ICS, which ask you to select a single source to use to authenticate all email accounts, KMS lets you choose a different authentication method for different accounts. For each mail domain you create, you can specify the name of one Windows NT and one AD domain, which will be used to authenticate users who use Windows NT and Kerberos 5 authentication, respectively.

AD integration causes KMS to import all users and groups within the target AD domain. AD simplifies mail user administration, letting you enter the information KMS needs when you create or update a user's AD account. AD integration requires the installation of Kerio Active Directory Schema Extensions. Although I didn't install the schema extensions to test this functionality, KMS's implementation appears to be flexible, supporting KMS mail users sourced from one AD domain alongside users defined through the KMS administrative interface.

Installing KMS was simple: I had only to select a location for the software and enter the mail domain name and a name and password for a mail administrator. KMS includes a Web server in support of Web-based client and administrative users. By default, it uses all the standard ports, so you'll have conflicts if IIS is installed on the same server.

KMS offers two administrative interfaces: a GUI and a Web-based interface. The Web interface lets you manage only Users, Groups, and Aliases, so it isn't full featured, but I found it easy to use. KMS's Custom Setup option lets you install the GUI and Help files to your desktop for full remote administration. And the Help files actually do help.

I started my testing by using both the Web interface and the GUI to create a set of users and groups. In KMS, groups serve a dual purpose: They're used for folder authorization and for group email distribution. Creating an email address for a group is optional.

The Kerio Outlook Connector is a replacement MAPI provider and requires Outlook's presence on the computer before it can be installed. After the installation, which is a routine process, you must create a new Outlook profile. In Outlook 2000, you configure the Kerio MailServer option, then manually add Outlook Address Book support. In Outlook 2003, selecting Additional Server types presents the Kerio MailServer option with preconfigured address book support. The KMS MAPI provider can coexist with other POP3 and IMAP accounts but must be the only MAPI provider in the profile.

KMS offers three assignable levels of access rights—Reader, Editor, and Administrator—and assigns Owner rights to a folder's primary user. Implementing collaboration features was pretty easy. Anyone who has Administrator rights to a folder can create subfolders and assign rights within the folder structure using Outlook or Kerio WebMail. KMS supports six folder types: Mail, Calendar, Contacts, Tasks, Notes, and Journal.

Users can share private folders the same way an administrator shares public folders. On the Sharing and Security tab of a folder's Properties page, select or type the name of a user or group and assign the access privileges you want to allow. Users who aren't owners must ask to see the folder before it will appear in their folder list, a process called Folder Mapping (in Outlook) or Subscribing (in WebMail).

Free/busy meeting scheduling worked well and was the easiest to implement of the products I tested. KMS looks only at a user's primary calendar and its subfolders when collecting free/busy information. Names from each Contacts folder that I marked for display as an email address book were available when I selected meeting participants. Also, KMS collects free/busy data only from those who use a supported client: Outlook with the Outlook Connector, Entourage, or WebMail.

KMS's built-in Web server supports two Web-based interfaces: Kerio WebMail for desktop use and Kerio WebMail Mini, a lightweight Web interface for use with PDAs and other handheld devices. Users will enjoy the full-featured, easy-to-use Web-Mail interface. I adjusted easily to the layout, which is similar to an Outlook Folder view, as Figure 3 shows. Right-clicking a folder or a mail item produces useful context menus, and a Settings button provides entry to options such as Rules, Out-of-Office setup, and the client refresh interval. Reminders pop up and provide Snooze and Dismiss options.

I found it easy to navigate KMS's UIs and administrative interfaces. Additionally, the AD extensions add a dimension of integration and manageability unique to KMS among the products I reviewed.

A Win-Win-Win Situation
Whether you prefer the high configurability of MDaemon, the flexibility of Ipswitch Collaboration Suite, or the thoughtful attention to detail and easy administration of Kerio MailServer 6, you won't find a bad product in this group. I designate KMS as my Editor's Choice for its well-rounded feature set, which was designed with the needs of SMBs in mind. Implementing KMS should be a relatively easy experience for users and not particularly difficult for administrators. Overall, I found working with KMS a pleasure.