E-mail messages have frustrated me for years because they are primarily plain old text. Almost all the other communications we see every day include different fonts, colours and pictures. By comparison, most e-mail is boring to look at.

This is changing, however. With the adoption of Windows- and Macintosh-based e-mail client programs that can send and display information in HTML, an e-mail message can convey graphical information in the same way as Web pages.

One e-mail client that supports HTML, Microsoft's Outlook Express, is becoming widely used because it is included with Microsoft Internet Explorer. Microsoft also sells a commercial program with HTML features called Outlook 98 (a separate program from Outlook Express, despite the similarity of their names).

Outlook Express and other e-mail clients with "rich text" features have begun to define a new way of communicating. Outlook Express 4.0 can send messages that contain different sizes and styles of fonts (including boldface and italics), embedded graphics, video, sounds, backgrounds (known as "stationery"), and more. If Outlook Express is configured to send plain text, you can click Format-Rich Text in a new message window and insert any HTML effects you like.

To get around the fact that many PC users are still stuck with plain-text e-mail clients, Outlook Express sends an HTML message in two parts.

The first part contains only your message's printable characters. This section of the message is displayed normally by plain-text e-mail clients. The second part is a full HTML file, complete with fonts and graphics. Plain-text e-mail clients interpret this as an attachment. Anyone with a Web browser can view the attachment as an HTML file, although doing this requires an extra step.

Rich-text e-mail clients, such as Outlook Express, however, display the HTML contents as the main message. The recipient never sees plain text unless he or she happens to click File-Properties-Details-Message Source. Then the HTML code, complete with bracketed tags, becomes visible.

A lively interest group has sprung up on the Internet to exploit the secrets of rich-text e-mail (not to be confused with the Rich Text Format, or .rtf, files supported by Microsoft Word and other word processors).

David Guess has created a Web site in which he reveals ways to insert scrolling messages, sounds, and marquee backgrounds into Outlook Express messages. His Stationery help page, at www.mindspring.com/~majik/docs.htm, is packed with tricks to make your e-mail distinctive for recipients with HTML-enabled e-mail clients while still being readable to plain-text users.

Guess has found many workarounds that make rich-text messages flow better on some less-than-compatible e-mail clients. For example, he describes how to edit an HTML file so recurring graphics appear correctly in Eudora 4.0.

To find a host of other sites with information on rich-text e-mail, go to www.webring.org/cgi-bin/webring?ring=oestationery;list.

• Brian Livingston's latest book is Windows 98 Secrets (IDG Books).