If you’re like most Americans, sending and receiving e-mail has become a daily ritual—like brushing your teeth or letting the dog out. The Pew Research Center (Washington) reports that 91 percent of Americans have used e-mail and 58 percent send and receive messages every day.

Businesses are catching on, too. Today, communicating with customers via e-mail has become a no-brainer for most companies. Still, smaller business owners may hesitate to make the leap when it comes to marketing with e-mail.

They have god reason. E-mail marketing comes with a steep learning curve, and the consequences of a poorly managed list or campaign can be disastrous.  Your carefully worded messages can land in junk folders, internet service providers can label you a spammer, and you could end up with thousands of dollars in fines.

But there are responsible ways to e-mail your customers, and the potential benefits are huge. Compared to more traditional forms of advertising, e-mail campaigns are very inexpensive—costing merely pennies per message. The viral nature of electronic communication means that your message may reach many more people than the original recipient.

A little planning and research can go a long way to keeping you out of hot water and front-and-center in your customers' minds. We’ve outlined some of the most important dos and don’ts to get you started.

Do build your own list

It’s tempting to buy a list of e-mail addresses. But unless recipients have said they want to hear from you, that’s a big no-no. And it’s a common mistake.

“If you just suddenly start sending e-mail to people, they’re going to get ticked off,” said Anne Mitchell, chief executive officer and president of the Institute for Social Internet Public Policy (Santa Clara, Calif.)

Making recipients angry is bad enough. What’s worse is when they label your message as spam, which sends a direct message to their Internet service provider not to accept messages from you. In rare cases, you can be identified as a spammer, in which case ISPs may block your Web site. Or you may need to pay hefty fines for breaking state and federal laws.

All of these disasters can easily be avoided—build your own list. When you collect e-mail addresses, tell people that they may receive e-mail messages from you. Be specific if you can. Let them know how often you want to communicate with them and why. And give them a chance to opt-out of this service.

Dave Ratner, owner of Dave’s Soda & Pet City, a four-store chain headquartered in Agawam, Mass., asks customers for their e-mail addresses at his cash registers. His point-of-service system allows him to collect that information easily and accurately.

Don’t e-mail too often

What’s too often?  That depends. Kevin Jackson and his wife Trina Underseth, owners of Domesticated Designs (San Francisco), planned for e-mail campaigns when they started their fashionable pet bed and linens business last spring.

“We, as customers, hate receiving sales e-mails,” Jackson said. “So we want to limit our campaigns. We look at how we want to receive e-mails and how frequently.” 

Because their business is based on fashion seasons, it made sense to shoot for two messages each year—one in December and another in the summer.

On the other hand, Metropawlis, a pet boutique in Milwaukee, sends out its newsletter 12 times a year. “Every month, we showcase what’s going on at our store,” said owner Geri Ray.

Segmenting your list is a great way to reduce the number of messages broadcast to each customer. Along with his monthly newsletters, Tom Murray, owner of Villa La Paws LLC (Phoenix, Ariz)., sends specially targeted messages to his grooming, day-care and boarding customers. This way, he’s able to announce a special rate to grooming clients, without bothering boarding clients.

“The most successful e-mal marketing campaigns feel like they’re speaking directly to the person, and list segmentation is a great way to accomplish this,” notes Jennifer Perez of Benchmark Email, an e-mail service provider located in Long Beach, Calif., that specializes in managing e-mail lists of small businesses.

“Don’t worry about bugging your customers, as long as your e-mails are relevant,” said Ratner.

The 2007 pet food recall is a classic example. “Customers were starving for information,” Ratner said. “Here was a chance to show my expertise.”

Do keep a clean list

It’s crucial to keep track of any bounced messages—messages that never make it to the recipients’ inbox. This is when an e-mail service provider can be a huge help. With these inexpensive services, you’ll get a report of the bounces after each e-mail campaign, allowing you to simply delete the addresses or look into why they bounced.

Murray calls customers if an e-mail bounces, just to be sure that he has the correct address. “We don’t just ignore them,” he said. “We try to rectify those once a month.”

Bounce-backs are sure-fire signs of a mismanaged list, so ISPs frown on too many of them. Keeping a clean list will help you stay on their good side.

Don’t forget the legal stuff

CAN-SPAM (Controlling the Assault of Non-Solicited Pornography And Marketing Act of 2003) regulates commercial e-mail messages. Being in compliance with CAN-SPAM will keep you out of trouble with those on your e-mail list and legal authorities.

First, your e-mail--including newsletters and purely informational e-mails--needs to be clearly labeled as an advertisement and include your valid physical postal address. In addition, each e-mail you send must include an easy way for the recipient to unsubscribe from your list. You must comply with unsubscribe requests within 10 business days, and you are forbidden to sell that e-mail address to anyone else.

Do carefully consider your content

With all of the technical and regulatory concerns, it may be easy to put content on the back burner. But the e-mail’s content will determine whether or not your message is valuable to recipients.

“People don’t like to be sold, but they will tolerate being educated and love to be entertained,” said Gina Watkins, a regional development director for Constant Contact, an e-mail service provider with offices in Waltham, Mass., and Loveland, Colo.

Murray’s newsletter includes articles from his staff, humorous stories, a calendar of events and a featured rescue animal. The articles themselves don’t appear in the e-mail. Instead, Murray writes headlines that are linked to his Web site.

Links also send a good message to ISPs. When recipients click on them, it shows that the sender has permission and that the audience wants to read what’s in the message. “I would recommend putting as many as six or seven links in an e-mail, if possible,” Perez said.

Links also help gauge what content is working and what’s a yawn. “I can track to see which articles get hit and by whom,” Murray said. “The adoption story is the number one story every month.”

Think of what will encourage people to open your message. “We like to include a funny picture,” said Cindy DeGray, who handles e-mail marketing for Daves Soda & Pet City. “We never used to do that but we noticed that it improved our open rate.” 

But be careful with photos. Size does matter. Enormous images can clog up servers and make it difficult for recipients to view your message. Finally, make sure that you have permission to use any images that you include. Simply scouring the Web for cute photos or clip art is a big no-no.

Don’t overwhelm your readers

You can pack a lot of information in a small space, but that’s not advisable. Pick a message and stick to it. If you have more to say, think about using your Web site or saving it for the next e-mail.

“Don’t get too wordy,” said Ray. “One of the things that’s mentioned about our newsletter is how clean it is.”  That can take practice.

“Decide what you want your e-mail to look like, and don’t send subscribers something they didn’t ask for,” said Mitchell. “The simpler you can keep your e-mail, with lots of plain text, the better the deliverability. It’s all a balancing act.”

Do watch your subject line

“The subject line is probably the most important aspect of your e-mail, because it gets you in the door,” Perez said.

For example, think of the headlines on the covers of magazines: "5 Dog Training Secrets" or "What Your Vet May Not Have Told You About Rabies."

The subject line can also help brand your company, said Watkins. And the right one will have recipients forwarding your message even before opening it.

But avoid “spammy” words, which are sure to land your message in the junk folder. “Stay away from any talk that sounds like a used car salesman or carnival barker,” Perez said.  (See "Words to Avoid.")

Do look to the future

An e-mail campaign takes time to build. “Don’t expect a huge impact immediately,” said Jackson. “This is an accumulative effect.”

Murray agrees. “If after three to four months you don’t get what you want, don’t quit. It takes a while to build a readership.”

To get the most of your e-mail list, keep it fresh by adding new addresses and segments. Tweak your message and subject lines to get the most of them. And consider dipping into other technologies like Twitter, Face Book and video e-mails.