For many of us, our e-mail client (mail program) chose us rather than the other way around. Apple's Mail sits in the dock of every new OS X-based Macintosh. If you're a Microsoft Office fan or liked Outlook Express back in the OS 9 days, inertia may have you using Entourage, Office's e-mail component. Or if you're partial to Web-based e-mail, such as Hotmail, Yahoo Mail or Gmail, you're probably using a browser by default to create, read and respond to e-mail.

But just because you didn't choose your e-mail program before, doesn't mean you can't choose one now. To get an idea of today's best of breed in Mac e-mail, I tried out the current versions of Apple's Mail (v. 2.1), Entourage 2004 (Microsoft) and Thunderbird 2 (a popular open-source e-mail client from Mozilla and kin to the Firefox browser).

I've taken a close look at all three contenders in five crucial areas of e-mail client performance -- components and capabilities, creating and sending messages, receiving and reading messages, searching, and message management -- and chosen a winner in each category. I'll also provide tips for switching from one program to another (in case what I found out tempts you away from your current choice), a list of little-known alternative clients and, of course, my overall recommendations.

Components and capabilities

The first question you probably have, and the first set of criteria for distinguishing among these programs, is "What's in the box?" What features are offered -- both core e-mail functions as well as any bonuses?

Mail server support

If an e-mail client doesn't support the types of mail servers you'll be accessing, its usefulness is nil. Most Internet service provider accounts for home and small business users run Post Office Protocol 3 (POP) mail servers. Some Internet providers, such as Apple's .Mac, provide both POP and Internet Message Access Protocol (IMAP). Mail, Entourage and Thunderbird all support POP and IMAP.

If you have a corporate e-mail account that runs on Exchange Server, you won't be able to use Thunderbird unless your account can be configured as a POP or IMAP account. (Ask your network administrator.) Mail and Entourage both support Exchange Server directly.

Entourage users can access and manage their Hotmail accounts without having to launch a browser. (Thunderbird provides Web-based account support via a Webmail add-on, but I couldn't get it to work.)

Ancillary features

In addition to handling your e-mail needs, Entourage and Thunderbird have other features that you may find useful (or essential). Because Entourage is "Command Central" for Microsoft Office, it provides the largest number of extras: an appointment calendar, a to-do list, notes and project management.

If your ISP offers newsgroup support, either Entourage or Thunderbird can double as a capable newsgroup reader. However, if you want to receive and read RSS Web site and blog feeds in your e-mail client, only Thunderbird is currently up to the task. Note: It's reasonable to expect that Entourage and Mail will add RSS support in their next versions.

Components and capabilities winner: Entourage.

Entourage supports every major type of account and server. Its excellent Hotmail support -- including the ability to check for new messages on a schedule -- is vastly superior to using a browser. Entourage provides an abundance of features that expands its scope beyond that of an ordinary mail client.