How R U? : Letter writing may have been transformed by computer, but the same, old rules still apply : THE ELEMENTS OF E-MAIL STYLE: Communicate Effectively via Electronic Mail, <i> By David Angell and Brent Heslop (Addison-Wesley Publishing: $12.95; 157 pp.)</i>

Poor William Strunk Jr. Sure, he’s achieved immortality; thanks tB. White’s revival and expansion of his classic, “The Elements of Style,” he lives on wherever clear, forceful writing is cherished. But thank God the late professor didn’t live to see the bevy of illegitimate “Elements of” progeny stumbling along in his durable footsteps.

The latest of these descendants, perhaps reflecting the declining vigor of the genre, is surely among the most dim-witted. “The Elements of E-mail Style” takes as its premise that electronic mail, to which I confess a middling addiction, is a different medium that requires a different kind of writing--one “that is clear and concise without sacrificing speed.”

Unfortunately, authors David Angell and Brent Heslop have largely proven the opposite. Their inane handiwork is enough to send anyone scurrying back to the vastly wiser teachings of Strunk and White, next to whose volume this new book is what is known on the Internet as a core dump .

“Choosing the right words for your e-mail messages is the foundation of effective communication,” Angell and Heslop grandly assert, as if it’s news that you shouldn’t write tenacious when you mean strawberry.

They suggest using “jargon only if you’re sure your reader will understand it,” and in a section headed “Use Cliches Sparingly,” the authors advocate “a careful use of modern, reasonable cliches” in e-mail, perhaps chosen from a list of 87 “commonly used cliches” (what other kind are there?) that they include. Or how about this advice: “For the best results, put what your reader wants to hear above what you want to say.”

To these guys, the ideal e-mail not only panders to its reader and relies on jargon and cliches, it’s also politically correct. E-mailers are urged not to refer to a “self-made man,” presumably even if the subject is Andrew Carnegie, and international e-mailers are warned: “Don’t say no directly to an offer made by a Japanese person.” But what if the question is, “Will you join me in seppuku?”

Worst of all is their endorsement of those little smileys--keyboard combinations known as “emoticons” that make sense only when you hold your head sideways; :- is a happy face, for example--”to help the reader decipher the writer’s original intent.” What a great idea! I have always felt that the absence of these accounts for most of the heavy going in Kant’s “Critique of Pure Reason.”

What Angell and Heslop have proven, at the end of the day, is that e-mail does not in fact require a new kind of writing--certainly not the kind of witless and self-indulgent raving of which there is already too much on that fast-developing frontier known as cyberspace, and certainly not the bloodless prose committed in this book, either. Clear, honest expression will do just fine.

E-mail is wonderful for a lot of reasons, not the least being the way it has all sorts of people writing--and reading--again. Just as it seemed that harried schedules, cheap long-distance rates and a clownish Postal Service had buried letter-writing forever, the art makes like Lazarus and bounces back to life in the form of electronic mail.

The troubles people have in this medium are the troubles they would have writing on paper, if they ever did such a thing: making themselves clear, not giving unintentional offense, avoiding bombast, knowing how casual to be and keeping the reader from dying of boredom. These problems are exacerbated only a little by how quickly one can pull the trigger on an electronic missive.

Fortunately, writing e-mail isn’t hard. As is the case with most self-help books, a better version of Angell and Heslop’s treatise could be written in just a few sentences. When writing e-mail:

* Be brief.

* Get to the point.

* Use plain English.

* Don’t try to impress by affecting an exaggeratedly formal style.

* Spell everything right; don’t be too proud to use spell-checking software, which even the best spellers find useful.

* In replying to a message, quote all or part of the original, but not so much that you’re a nuisance.

* Write important messages off-line with your word processor. It makes editing easier and permits more careful thought.

* Bear your audience in mind. In casual exchanges, e-mail is really a hybrid of writing and speech, so when e-mailing your sister in Philadelphia it doesn’t matter if your messages look like e.e. cummings on a bender. If you’re e-mailing an important business contact, on the other hand, you’ll want to get dressed up, so to speak.

All that said, there’s no harm in e-mailers consulting a writing guide. The book to look for is a slender volume by a couple of fellows named Strunk and White, who can be proud that what they set down about writing generations ago remains true whether your implement is a quill or a microchip.