“…details at eleven.”

If you grew up watching local news broadcasts in the ’80s, you probably recall the teasers touting all sorts of hidden dangers that could affect your family. And of course, when the payoff came, there was a sigh of relief as we all realized the story was blown way out of proportion – merely a ploy to raise ratings. Fortunately for us, our pantries, medicine cabinets, and refrigerators were not just teeming with potential killers, and now we can all read our scary “hiding right in your cupboard!”-style headlines on Facebook or Twitter instead.

Even though those ’80s news threats were mostly imagined, there are some legitimate “hidden killers” when it comes to email marketing. For senders, one of the biggest potential minefields comes when you decide to send to an old list of email addresses. It’s probably happened to you: someone from another team (or a superior on your own team) brings you a list of addresses that is clearly outdated. They were acquired sometime during the Clinton administration, last mailed 2 years ago (or was it 3?), and probably haven’t been updated…ever. They gave you permission to send all those years ago, so sending to them now is no problem. You’ll remove the hard bounces, then you’re left with a good list of opted-in contacts just waiting to boost your sales numbers. Sounds like a win-win, right?

Not so fast. Even if you received permission to email these contacts, if it happened very long ago there are a number of reasons that permission may not matter. The address may have been abandoned, deactivated, reallocated to a new user, or even repurposed as a spam trap. Let’s look at each of these scenarios and how they can wreak havoc on your sender reputation.

Abandoned addresses

Email addresses, though personal, are a somewhat disposable commodity. With workers switching jobs more than ever, and freemail services providing a myriad of email address options, it’s not uncommon for a recipient to simply abandon an email address. The address remains active and accepts mail, but the user rarely if ever accesses the mailbox.

Most mailbox providers, as we’ve previously discussed, rely heavily on engagement metrics to filter mail. Senders who see good engagement rates from their recipients are more likely to reach the inbox. What you may not know is that many of these providers also look at how many “zombie” mailboxes you send to regularly. If you are frequently mailing to recipients who rarely if ever check their mail, that can have a negative impact on your delivery rates.

Deactivated addresses

This one tends to be the easiest to see: when you send to an address, the message is bounced and you receive a rejection response. Many senders simply gloss over this point because their ESP automatically suppresses bounces, so they know they won’t be mailing to them again. But even a single send to a large number of invalid addresses can cause delivery issues. Once you’ve damaged your sending reputation, the time and effort required to repair it are often much more than would have been required to ensure the list was clean before sending.

Reallocated addresses

If you haven’t mailed to an address in months or years, it’s possible the address was abandoned or surrendered by the previous owner and now belongs to someone else. If this is the case, that recipient hasn’t provided you permission so any mail you send to them is technically unsolicited. These recipients are much more likely to mark your message as spam or report it to a blacklist or spam filter provider.

This scenario is most likely if you haven’t mailed a recipient in well over a year: most webmail providers keep an address active for a minimum of 6 months before it is deactivated, and it’s not uncommon to see another 6 months or more lapse before the address is reassigned to a new user. If the address belongs to a corporate domain, though, the turnover time is often faster.

Spam trap addresses

Of all the problematic addresses, these have the potential to cause the most damage to your reputation and sending ability. Abandoned addresses (and sometimes entire domains) are brought back to life to serve as spam traps, either for the domain owner or a third-party provider like Spamhaus. These trap admins monitor all mail sent to their traps and take action against senders who are seen to be mailing traps with regularity. (For more on spam traps, check out Deliverability 101: Spam Traps.)

Spam traps are most dangerous because they are inconspicuous. They don’t reject mail or throw any red flags to indicate the address has been repurposed as a trap. If you haven’t sent to an address in more than a year, the potential risk of it being a spam trap is greatly increased. While there’s no hard and fast rule, it’s often said that addresses typically remain dormant for 6 to 12 months before being reactivated as a trap.

As a marketer trying to squeeze all possible value from limited resources, sending to an old list can be quite appealing. That appeal, however, vanishes pretty quickly when that old list causes spam folder placement, an ISP block, or even a major blacklisting – preventing all of your recent, engaged recipients from getting the mail as well.

– BG