IN JORGE LUIS BORGES' short story, the "Library of Babel," the universe is a near-infinite library, filled with identical-size books. Their texts are random strings of letters. Most are devoid of meaning, though here and there, by sheer chance, are phrases, sentences, even entire pages of apparent sense.

The occupants of this universe are tormented by the certainty that somewhere in this impossibly vast collection are books of perfect wisdom and beauty, including one book that would explain the meaning of the library.

The story comes to mind sometimes when I look in my e-mail inbox. I've never bothered to install the proper spam filters. So I still get dozens of offers for mortgages, imitation Rolex watches, discount drugs, porn and pirated software. They are all doing their best to disguise themselves. Some look like missives from long forgotten friends, baited with subject lines that say "Write back to me, please," or "Missed you last week."

Most, however, look like snippets from the "Library of Babel." They have incoherent subject lines, such as "To dance an battery," or "You wakeup it demise stores." Within is more gibberish, sometimes several hundred words of it. The sales pitches hide inside image files or reside a click away on some Web site. The nonsense words are there to trick the spam detectors, so-called Bayesian filters, which rely on word probabilities to distinguish between junk mail and real e-mail.

Certain words and phrases are more common in spam ("refinance now," "Viagra," "babes"). So, the spammers load their pitches with irrelevant and statistically improbable words to make them appear human and idiosyncratic. Some look like SAT study sheets: "transmutation oblique a dichotomize," and "ammeter try partook" says one ad for "topqualitydrugs."

But filter-evading spam come in different styles. Some have a grammar of sorts. Instead of random-word generators, they use random phrase-generators. Some skirt the edge of meaning, or manage to sound evocative: "Rule enough forest land. Build, yard ice divide, the like order. We, door appear, very night," reads one.

Not surprisingly, some people see poetry in this, or use the phrases to make poetry. The e-culture's term for this is spamoetry. A Google search turns up a few examples on blogs and on bulletin boards. A gamer called Creepy_Smell posted a spam-based composition that begins: "Let us show you the magic spaniard/ The giant rubber inflatable disk drive."

I prefer the prose versions of spam nonsense, and was surprised for a while by flashes of brilliance, until I discovered that they copped phrases and sentences from classic literature. Sentences from the works of L. Frank Baum, author of the "Oz" books, have made for some interesting spam. It took a bit of Googling to discover that the source of one dull spam series was an analysis of George Washington's will. Tracts from "David Copperfield," peppered with references to Dora, Micawber and Uriah Heep, have been cropping up in my mailbox of late.

Even plagiarism can be have a degree of originality, however. It took sentence fragments from two different chapters of David Copperfield to arrive at this intriguing spam sentence: "I began the day with another dive into the Roman bath, and it was so expressively done, that she had no need to say a word."

It's hard to believe that a computer program made that combination. But who knows exactly how it was done. Chance, like the monkeys at the typewriters, or the mystical creator of Borges' library, can theoretically mimic anything produced by human intelligence. The game between spam generators and spam filters is a contest between computer programs. It's all about probabilities and algorithms.

I see a subject line like "Is hurt in sad," and I involuntarily register little hits of emotion, before I remember that this is a computer talking. But then, I'm only human.

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