LOS ANGELES - Stephanie Fessler doesn't drive a hybrid car, compost her orange peels or take reusable cloth bags to the supermarket.

But two months ago, Fessler joined countless other business people in doing one environmental good deed daily. At the bottom of every e-mail message she sends, she includes this message: "Save Trees. Print only when necessary."

"This is something I can contribute in my crazy busy life," said Fessler, 29, who works for a Los Angeles public relations company. "It reminds other people about environmental awareness and reminds me on a daily basis."

The trend took off last year, when the environmental Web site TreeHugger.com encouraged readers to add the "don't-print" plea to their automatic e-mail signatures.

Since then, the message has spread beyond the granola-and-Birkenstock crowd to the cubicle armies of corporate America. Architects, airline employees and even button-down accountants have gotten in the on act, as have companies such as media giant News Corp.

The parent of Fox Television offers employees a catchy admonition that riffs on the company's "Cool change" environmental initiative: "Be cool, consider the environment. Please don't print this e-mail unless you really need to."

At Bovis Lend Lease, a 10,000-person worldwide project management and construction company, so many employees began adopting the please-don't-print line that executives agreed to grant a sole exception to the company's rule against personal e-mail signatures.

As many as 1,000 button-down accountants and consultants at Deloitte & Touche have adopted some version of the line, an executive said.

"It's a testament to how cool green is that this particular message is appearing in so many business communications," said John Palfrey, executive director of the Berkman Center for Internet and Society at Harvard University Law School.

Environmentalists say the don't-print message has merit. Despite 20th-century predictions of a paperless office, Americans use enough letter-sized paper every year to build a 10-foot-high wall that would stretch from New York to Tokyo and beyond, according to Greenprint Technologies, which sells software to eliminate unnecessary pages before printing.

At the same time, an estimated 97 billion e-mail messages whisk through cyberspace every day. Technology trackers say more e-mail messages invariably mean more printouts, if for no other reason than that printing has become a habit. Last year, 53 percent of people surveyed told technology research company IDC that they print more because of e-mail. That means more paper, and more energy to either shred or recycle it.

The growing mountains of printed pages encouraged Michael Graham Richard, Treehugger's editor, to get behind the please-don't-print movement after he saw the auto-signature for the first time last winter.

"We all know that many people print e-mails for no good reason, wasting tons of paper," Richard wrote on the site last March. "Lets do something about it, dear reader ... Add the following lines to your e-mail signature: 'Eco-Tip: Printing e-mails is usually a waste. Make this tip go viral, add it to your e-mail signature.' "

To some, the incarnations of "please don't print this" -- personalized with clever witticisms or written in bold green text alongside a picture of a tree -- are a new, socially responsible form of viral marketing.

To others, the tips are an empty, greener-than-thou finger wag.

"You're saving a landfill by not using more paper, not saving the planet," said Jake Munsey, an executive at Fox Cable Network's Fuel TV who has stopped using the eco-tip. "I started thinking, 'What really is this going to change?' "

Lighting designer Rob Guglielmetti, a blogger and ride-his-bike-to-work-every-day environmentalist, said as much to his boss a few months ago when the leader suggested using the enviro-missive on all company e-mail.

"People get this kind of smug satisfaction about how green they are -- hey, look at me, look at how great we are, we as a company are trying to teach you about sustainability and saving trees and saving the planet," said Guglielmetti, who lives in Boulder, Colo.

On his blog, rumblestrip.org, Guglielmetti offered a sarcastic list of alternative green e-mail signatures, including, "Printing this message kills trees. Print is murder!"