Research from Pivotal Veracity and other deliverability service providers shows that 20% of marketers' opt-in messages were blocked or sent to junk folders in 2009. Deliverability is a challenge that is becoming more complex as consumers read e-mail across multiple platforms such as work laptops, home PCs, iPhones and Blackberries. Your e-mail subscribers are also talking about your brand and reposting your offers and content on their Facebook and Twitter pages.

For years, deliverability has been the bogeyman of e-mail marketing. Warding off its negative consequences has been a black art practiced by deliverability specialists, shrouded in the mystery of their technical talismans. While the complex nature of deliverability can't be denied, the fundamentals are simply good marketing practices predicated on a respect for customer preferences. It's time to put the 'ability' back in deliverability.

As many e-mail marketers know, to comply with CAN-SPAM you must include an unsubscribe link and your postal address in e-mails, as well as make sure your e-mail headers or subject lines are not deceiving.

There are plenty of reasons to keep your list clean. First and foremost is reputation management. As your stream of e-mails reaches receiving servers, it is actively monitored to determine whether or not you are a spammer. A high bounce rate is one sure indicator.

When attempting to comply with CAN-SPAM requirements that prevent advertisers from sending e-mail to consumers who have unsubscribed, many share their physical suppression lists or opt-out lists with their third-party advertising partners.

For many years, direct marketing messages were mostly about a company and its products, with little thought given to the recipients and their needs. With inboxes filled thanks to the popularity of e-mail marketing, irrelevant information is likely to be ignored or treated as spam.

As the CEO of an e-mail marketing service provider, I receive a lot of e-mail. That shouldn't surprise anyone, least of all me. But even I was startled when I read Forrester Research's US E-mail Forecast 2009-2014 report. In the report, Forrester predicts that by 2014 individual consumers will receive an average of 9,000 opt-in e-mail messages a year. That breaks down to an average of more than 24 e-mail messages a day, or more than one e-mail per hour.

Most progressive marketers know that relevance is essential to driving strong customer response. To move to the next stage in customer engagement, deepen loyalty and encourage brand advocacy through e-mail programs that are not only meaningful, but connected to an integrated marketing strategy.

In a down economy, one might think a sale is the way to a consumer's wallet, but you may be surprised to know an innovative group of marketers is focusing on why to buy. Fashion retailers are proving to be trendsetters in more ways than one — they're giving e-mail subscribers a strong point of view.

The days of "one-size-fits-all," "batch-and-blast" e-mail marketing are gone. In its place is "e-mail-plus," a new age e-mail marketing strategy that uses e-mail in combination with other one-to-one marketing tactics and technologies to accelerate conversation and optimize ROI.