Vendors that send e-mail marketing messages to Margaret Farmakis better monitor their unsubscribe inboxes carefully over the next three months. The senior director at Response Consulting is going undercover, as she puts it in a blog post, by unsubscribing from all the marketing e-mails she receives and tracking various data points in the opt-out experience.

The point? "To unearth the sometimes hazy business of the unsubscribe process for an upcoming Return Path email study," she says. Farmakis is investigating how responsive brands are to customers who opt-out of receiving their emails. She'll be looking at a wide range of factors from if there are clear unsubscribe options available to whether the marketers asks her to fill out a quick survey on the opt-out landing page to find out why she is unsubscribing.

Return Path's unsubscribe study will be released at the end of the year.

Careless

More than likely Farmakis is going to find that marketers are sloppy with their opt-out practices - at least that was the conclusion from a recent Responsys survey, which found  4% of retail email unsubscribe requests usually fail. Of more concern, though, are increases in the frequency and amount of emails being sent out to consumers after they have made unsubscribe requests - 30% of online retailers sent subscribers at least one email following an opt-out request in 2010, compared to 26% in 2008, the survey found.

Clamping Down

Senders that don't pay attention to their opt-out requests - or worse, deliberately ignore them - are toying dangerously with ISPs. Increasingly, ISPs are basing their reputation models on user complaints, according to a special report on domain reputation by MarketingVox. In other words, the more complaints that are generated about your e-mail operations - such as a failure to process an opt-out request - the more likely the rest of your mail will land in the spam folder