How can we improve the quality of our email distribution lists?


Clients often ask questions about email engagement in the quest to fine-tune their marketing practices.  Those conversations typically lead to discussions about email hygiene.  Most marketers carefully watch open and click rates of different customer segments.  They experiment with different sales messages, email creative and offers.  Many layer in additional tests of send times, split subject line testing and other mechanisms to optimize performance.  This in turn leads to evaluating metrics and how they compare with other organizations of similar size.

The piece that is too often missing from these conversations is list quality, so we will explain why this is important.

Improving Email List Performance

My experience is that most publishers are not disciplined about cleaning their email lists. Success of the channel is too often judged by list size and not quality/performance. If a list grows, it's deemed a winner, and if not, the list manager is questioned. This problem is often worse in instances where advertising is sold (in these emails) on a CPM basis, rather than on % opened.

Good hygiene practices often lead to improved performance, not worse. It's a recommended practice to clean your list on a consistent schedule. Granted, to what level will vary by company, but it is absolutely a 'best practice' to make it an ongoing process.

The Importance of Email Hygiene

At the risk of oversimplification, how a list performs (engagement) has a lot to do with its condition. Every send contributes (no matter how large or small), so overall performance is measured by much more than any single send. When you launch an email campaign, the ISPs are monitoring many things, from open rate and send frequency, to known SPAM traps and bounce rates. If you have a lot of junk on your list - e.g., old or made-up addresses, inactive addresses - your in-box placement will suffer. Over time, the bad behaviors have a cumulative impact and the whole IP is impacted. This can take months to remedy, and it is a slow, arduous and debilitating process.

Beginning the Hygiene Process

Start by examining your data collection practices. At every possible entry point - including call centers, websites, live events, sweepstakes, etc. - make sure that email addresses are collected with a clear description of how the address will be used. If the use cases vary, make sure that they're tracked and tagged in some way that all company users understand the conditions of opt-in. Do not buy, rent or trade email lists. Most credible ESPs will not allow these lists to run on their IPs, so save your money. Getting a direct opt-in from a customer is an invitation to communicate. Treat it with respect, providing only what they asked for, and at the frequency you promised.

Most outbound email from businesses are one-way communications, not a dialog. Consequently, email engagement metrics help you "read" how customers feel about your communications. How often (and if) they open your email tells you a lot about their level of interest. At least their level of interest in hearing from you via email. Studying behaviors of customers versus non-customers, frequent versus infrequent users, new customers versus old - these types comparisons will inform your sales and marketing efforts. The lack of activity can be even more informative. Using it to clean your list strategically can drastically improve list performance.

Isolate email addresses that have never opened an email. If the addresses are more than about 180 days old, consider a "last chance" email before removing them from your list permanently. Old addresses can be recycled by ISPs into honeypots ("decoy" email addresses) and you don't want to take the chance of having those on your list because of the negative impact on deliverability. For the remaining, inactive addresses, deploy similar re-engagement messaging, with a clear plan to suppress non-responders over time. Pay careful attention to the subject lines in your efforts, as the "click" response is critical. This indicates there is a person on the other end, and that you have a viable email address. While you would like them to re-engage of course, knowing the address is good is more important from a hygiene perspective for an address that has never clicked.

If you want to take it a step further, look at the syntax of the email addresses (never opened) if your in-house systems do not screen emails at the time of capture.  Some general guidelines including making sure all email addresses have an "@" character (it is required) and removing role-based and group email addresses (e.g.,, as these are often accessible by multiple users and you do not know which signed up for email (it is likely unwanted by the others). Note: the tolerance for inactivity will vary by company, and by type and/or frequency of sends, but I would recommend 90 days as a starting point. If you are sending a daily communication however, 3 months is probably too long to ignore a "no activity" email address.

Remember too, that email engagement from a deliverability standpoint is completely siloed from all other channels. You could have a customer using your app or website every day and yet emails, to the very same customer, sitting unopened in their inbox for months, could be doing damage to your send reputation. This is precisely why discussion of email engagement must be paired with around send practices and hygiene.

Once you've started intelligent hygiene practices, your open and click rates should increase. Your list will be smaller, but the focus on active, engaged email behaviors will have a positive impact on your sales and marketing practices.

Wendy Hurwitz is a highly-regarded media executive with responsibility for creative development, campaign design and execution, marketing automation processes and business strategy consulting for LEAP's client community. Prior to joining LEAP, Wendy served as Vice President of Audience at Sightline Media Group. She is a Certified eMarketer (CeM) and author of the book, "An Executives Guide to Managing Email."

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