The CAN-SPAM Act has now been law in the US for more than four and a half years, yet many marketers misunderstand the law, how it applies to their business, or fail to know where the law falls short of best practices.

The Federal Trade Commission (FTC) has moved to enforce some key measures of the Act by going after those that egregiously use e-mail for fraudulent or deceptive activity, yet spam hasn't abated. Major Internet service providers (ISPs) continue to block 80% to 90% of the e-mail reaching their networks as spam or phishing, much of it actually being CAN-SPAM compliant! This is why marketers should not only seek to comply with the law, but understand how listening to the wants and needs of each subscriber is the best action they can take toward optimizing their e-mail program.

First, do no harm. Follow CAN-SPAM by providing a clear and easy way for your subscribers to opt-out of your e-mail messages, then honor those requests as quickly as possible. The recent FTC rulings say that you can't require the recipient to visit more than a single Web page or provide a password or any other information to unsubscribe, so do some checking to ensure your unsubscribe mechanism is compliant. However, don't forget that the Act also does explicitly permit you to provide a menu of subscription choices to your subscribers, such that they may opt-out of your promotions, for example, but stay subscribed to your monthly newsletter.

Companies who provide this type of profile/subscription page see fewer complete opt-outs since they've provided their subscribers with a way to opt-down.

Second, avoid temptation. CAN-SPAM allows marketers to send unsolicited e-mail messages…but don't do it! The Act says as long as you provide a notice of advertising or solicitation, your physical mailing address, and a working reply address or other internet mechanism to manage opt-outs that this is an accepted practice, but it will damage your brand, e-mail reputation, and in turn the ROI from your e-mail channel.

The best practice for deliverability and optimizing the return from e-mail is to send only to those that raised their hands and gave you explicit approval to send them e-mail. CAN-SPAM calls it affirmative consent, and with it, you still have to provide your physical mailing address and an unsubscribe mechanism, but you can do away with that notice of advertising or solicitation, which should aid your ability to avoid content-based spam filters.

Last, leverage your transactions. CAN-SPAM allows you to send transactional or relationship messages without offering an unsubscribe mechanism. The first e-mail you send to a subscriber or new customer is often as a result of something he or she has done, such as made a purchase or subscribed to your publication. This first welcome e-mail is often the most opened or clicked communication a marketer ever sends and can include commercial information, provided that the e-mail subject line is non-commercial (for example Welcome to Widget Co., Order Receipt Enclosed), and that the transactional information precedes the commercial or advertising information.

Even better is if you can make that ad relevant to the product the customer just bought. In fact, learning to plan and optimize each communication with each individual subscriber is the ultimate key to a thriving e-mail marketing program.