E-mail etiquette may be poor, but that’s helping Elizabeth Danziger’s business.

Danziger has run her one-woman corporate writing consultancy, Worktalk Communications in Venice, for 28 years. Because e-mail is the biggest challenge in business communication today, she has developed guidelines for electronic messages and teaches them to executives at her client companies, including Southern California Edison, Ernst & Young and Metropolitan Water District.

Her first rule: don’t be in a hurry to push the “Send” button.

“People are upset, they type out their feelings and hit ‘send,’ ” she said. “As the message vanishes from their screen, they realize it’s going to the wrong person or they made a promise they can’t keep. But by then it’s too late.”

Danziger also suggests that writers start messages with a salutation and briefly introduce their topic to avoid e-mails that sound demanding or brusque. She warns that readers will judge a writer’s professionalism by the grammar and punctuation in a short e-mail.

Finally, senders need to know that e-mails are often redirected to people never intended as recipients.

“You should assume that the one person you don’t want to get the e-mail will get it within 24 hours,” Danziger said. “People often forget that e-mails last forever.”