• Remember that e-mail is not private.
You can add to your signature line as many disclaimers as you like that your e-mails are "privileged and confidential," but the reality is that once you put something out on the Internet, or even on your company's internal system, you have no control over where it ultimately ends up and who sees it. Don't count on simply deleting messages to protect you; most e-mail systems have automatic storage features, meaning that your e-mails could eventually be recovered. No matter how much you trust the person you are corresponding with, the best rule is to never put in an e-mail anything that you would not want on the front page of a newspaper or as the lead news story on television.

• Casual is okay, sloppy is not.
E-mails do not require the structure of traditional, formal, written correspondence. It's perfectly acceptable to begin an e-mail with "Hi, Bill," or even just "Bill," instead of "Dear Mr. Smith:" but take care to use correct grammar and make sure everything is spelled properly. Proofread, proofread, proofread! It's far too easy to accidentally leave out a word that changes the entire meaning of your message.

• Observe accepted e-mail etiquette.
Be concise and to the point. Don't type in all capital letters (that's considered shouting), but don't type entirely in lower case, either; capitalize where appropriate. Don't spam, forward messages or attachments without permission, forward chain letters, or send or forward e-mails that contain libelous, defamatory, offensive, racist, sexist, or obscene comments.

• Before you hit send, be sure your message is complete and is going to the right person.
Sending a blank or incomplete message can be embarrassing or worse. When replying to an e-mail, take care not to hit the “send” button prematurely. For e-mails you originate, make entering the address the last thing you do so the message can't be sent until you are ready, and always check to make sure the address is accurate. We may laugh at stories of people who have sent messages to the wrong people, but the reality is, such errors can damage your reputation, cost you business and money, and ruin relationships.

• Remember that e-mail is not 100 percent reliable.
Spam filters and system failures can cause messages to end up lost in cyberspace. If it's important, request a receipt confirmation, either by using the tool in your e-mail software or by specifically asking the receiver to acknowledge the message.

• Use your out-of-office auto-reply if you are not going to be able to answer e-mails promptly.
If you won't have access to your e-mail for a day or more, use an auto-reply to let people know that there will be a delay in your response. Let them know who to contact if the situation is urgent. When you are in the office, answer your e-mails as promptly as possible while still maintaining your productivity. You may, for example, want to set aside two or three times a day that you read and reply to e-mail. Stopping to read and reply each time a message comes in could mean you will do little else besides deal with e-mail. Conversely, be understanding when you do not receive prompt replies from others. Recognize that they may be busy, in meetings, or out of the office, and be patient. If an immediate response is required, pick up the phone.

• Be cautious with abbreviations and acronyms.
E-mail has spawned a language of its own, but don't use abbreviations and acronyms your reader might not understand, or worse, might misunderstand. For example, SWAG usually means "scientific, wild-ass guess" but in some circles, it also means "soft ware and giveaways." Even the common LOL, which usually means “laughing out loud," could instead be intended to mean "lots of luck." It's always better to spell things out and be clear.

• Use humor sparingly or not at all.
E-mail is a one-dimensional communication without the benefit of tone or facial expression. Even including a smiley face or other humor indicator may not achieve the desired effect. It's much safer to just avoid using humor completely.

• E-mail praise, but not reprimands.
E-mail is a great tool for quick and timely electronic pats on the back, but should never be used for any sort of negative appraisal.

• Include a subject line appropriate for your message.
Focus on one issue per e-mail and make it clear in your subject line so the recipient can find your message quickly and will know what it's about. If you develop a long email exchange and the subject shifts, change the subject line.

• Use a signature line with your full name, title, and contact information in case the person you are e-mailing wants to contact you by a means other than e-mail. Include links to your website and blog if you have one. A brief marketing message is also acceptable.

• Do not let e-mail replace human interaction.
E-mail may be efficient, but we still need real face-to-face conversation.

If you have a business, it should have a comprehensive e-mail policy, and every employee should be trained on what that policy includes. Make e-mail work for you, not against you.

Jacquelyn Lynn (www.jacquelynlynn.com) is a business writer and speaker, and the author of "The Entrepreneur's Almanac."