(FORTUNE Small Business) – Feeling overwhelmed by e-mail? Just plain annoyed? You're not alone. E-mail may have become a valuable business tool, but your in box is probably cluttered with unsolicited messages, sales pitches, and annoying discussions that were once held around the water cooler. You can't slam your door to shut out all the nonsense, but many popular e-mail programs have tools to help you manage the rising tide of paperless correspondence.

I will focus on two of the most widely used: Outlook Express, which comes as part of Windows 95 or 98 (or Office 98 on the Mac), and Qualcomm's Eudora, which has both a shareware version and a more elaborate commercial edition, Eudora Pro.

I have to admit that Outlook Express is among the rare Microsoft products that work well in their first iteration. Don't confuse Outlook Express with Outlook, a bloated product (part of the Microsoft Office suite for Windows) that does calendars, meeting notes, and other desktop tasks in addition to e-mail. Express is a pure e-mail product that, like other e-mail software, can collect mail from several different accounts so that you can consolidate and manage all your messages.

But getting the mail is just the first step. Sorting the digital wheat from the chaff is the priority in using your time better. The filtering tools in e-mail are variously labeled RULES or FILTERS or IN-BOX ASSISTANT. Whatever their nomenclature, it is worth investing the 20 to 30 minutes it takes to learn to use them.

Both Eudora and Outlook Express have tried to make the process as simple as possible. Eudora Pro lets you pick a message as an example and apply several preset rules to it. You could, for instance, create a rule that moves any incoming message not addressed specifically to you into a junk mail folder. This will reroute much of the Internet spam, which often uses fake names or mailing list names. I prefer not to send these messages directly to the trash just in case an important message gets dumped.

Filters can also flag important messages, setting up, for example, a rule that sends any mail from your boss to a special folder. Some programs will even let you change the color of the message title, to make sure you don't overlook it. You can create rules to move messages with certain topics or key words into folders automatically. You can ship mail from annoying correspondents directly to the trash. And you can also send automatic responses, so people who write to you will know that you're away on business or on vacation when they don't hear from you.

The biggest advance in e-mail in the past couple of years is in the way it looks. The HTML codes used for Web pages have worked their way into e-mail. The newer e-mail products handle these messages well, showing them in all their glory, complete with eye-straining fonts, ad banners, and flashing graphics. If your e-mail supports viewing HTML, you probably have templates to send your own eye-straining mail and not feel left out of the design frenzy.

HTML mail provides an opportunity to send lively messages to your customers, but remember that a simple message with substantive content beats out a fancy pulsating billboard of no relevance. Otherwise, your mail may end up moved directly to the trash without ever being seen.