E-mail is still one of the best ways for small businesses to reach customers and prospective buyers. But send too many unsolicited marketing messages and you run the risk of people thinking you’re a spammer.

Thankfully, there are weapons in the war on spam that companies can use to make sure their legitimate marketing messages aren’t mistaken for spam.

Certifying outgoing e-mail

One new tool is signing up with an e-mail certification service, which puts a sender through a rigorous authentication process to prove they’re the real deal. The services work on the same principle as website verification services such as eTrust or VeriSign. Companies submit certain information about themselves to a certification agency, including a physical address, Dun & Bradstreet listing, what their e-mail practices are, or how they obtain their e-mail mailing lists. If they’re approved, they can place an icon on messages they send showing that they’ve passed inspection.

One of these e-mail certification services is GoodMail, which uses a seal of approval that looks like a blue ribbon hanging from a white envelope. When a company has the GoodMail seal of approval, the blue ribbon icon appears on the outside of an unopened message in the recipient’s e-mail inbox, as well as on a toolbar near the top of the opened email message.

GoodMail has already signed up 400 companies for the service, including brand names like Shutterfly, Petco and StubHub. The four-year-old Mountain View, Calif., company also has deals with Internet service providers and e-mail service providers that account for about 65 percent of all e-mail traffic in the United States and is negotiating others, says Charles Stiles, vice president of business development. The service costs $1 to $2.50 per million messages, based on volume.

Although most early customers are big companies, GoodMail is actively pursuing small businesses too, because they’re most likely not to have IT staff to deal with spam problem, Stiles says.

GoodMail isn’t the only company with an e-mail authentication service. Return Path offers an e-mail white-list service, called Sender Score Certified, that the company claims covers 1.2 billion e-mail inboxes. Return Path recently announced it was acquiring another competitor, Habeas, which markets a service that follows large e-mail senders to see whether they’re complying with federal spam laws. Other companies with e-mail security technologies of one favor or another are Cloudmark and Commtouch.

SIDEBAR: Other Strategies to Avoid Looking Like a Spammer

Certifying outgoing e-mail is one step companies can take to let customers know they’re not spammers, but there are others. E-mail experts say they also need to:

  • Deliver material the customer expects. If customers sign up for a free newsletter about pet care, don’t mail them mortgage offers.
  • Stick to stated mailing frequencies. “If you say you’re going to send weekly mailings, don’t send out three in one week to make quota,” says Stiles, who was the postmaster at AOL before joining GoodMail and dealt with spam-related issues on a daily basis.
  • Make unsubscribing as easy as subscribing. If someone chooses to unsubscribe, do it immediately. “Don’t ask them 15 times, just get them off the list” as quickly as possible, Stiles says.
  • Block employees’ access to unauthorized Websites. The further employees wander on the Web, the greater the risk they could inadvertently let a hacker get onto the company’s network and use it as a botnet to launch spam attacks. Avoid it by using Web blocking software and creating explicit policies about where employees can and can’t go online.
  • Check your online reputation. If you get on a spam blacklist like the kind kept by Habeas, your customers might not receive your mailings.
  • Avoid spammer language. Pick your words carefully so you don’t accidentally include language in email marketing pitches that set off spam filters at ISPs and email service providers.