When Subscribers Stop Opening Emails

As you continue to send marketing emails over time, your list continues to grow, and your engagement metrics continue to drop. Over time, the number of long-time subscribers on your list increases. These subscribers have a higher chance of becoming uninterested in your email messages, which they express by failing to open or click. This growing population of unengaged subscribers causes the overall metrics of your emails to drop.

So What?

ISPs are monitoring email engagement metrics and making decisions based on this. If your subscribers are less engaged than a competitor’s, then your email may get delivered later.

It is not uncommon to see Gmail “hold” your email for a delayed delivery if your engagement metrics are sub-par. If you are not monitoring sending to live seed email addresses, or using a deliverability monitoring service, you could be missing these warning signs.

Delayed Sending

How can you tell if your sends have been delayed? In Gmail, you can tell from the timestamp difference before and after opening the email. In the Gmail inbox, you will see a timestamp like the following:


After you open the email, you will see the timestamp for when the email was sent. If the times match, like in this case from Bed, Bath & Beyond, the email appears to have been delivered immediately upon arrival:

Bed Bath and Beyond Timestamp

In the following example from Gymboree, the timestamp in my inbox displayed 12:12 pm:

Gymboree timestamp

However, upon click-through, the timestamp displayed is 11:18 am, about an hour earlier:

Gymboree Timestamp 2

I suppose an hour’s delay isn’t too unreasonable and could be caused by other factors at Gmail aside from inbox engagement, but I have seen delays for some brands that are much longer.

This can be a real issue, especially if your offer is time sensitive, like a flash sale, or an email sent on Cyber Monday. Furthermore, if your open and click-through rates drop low enough, an ISP may choose to send your message to the junk mail folder, or worse, not accept it at all (aka it goes “missing”).


Black is bad in email. If your unengaged subscriber population continues to grow, then so do your chances of an email address becoming classified as a spamtrap.

A spamtrap is essentially a dead email address that spam software companies monitor for sending. Sending to a spamtrap can land you on a blacklist. This prevents your emails from getting to the inbox by anyone who uses that spam software for filtering.

ISPs and corporations use spam software to keep the junk out of your inbox. Of course, you as a retailer, don’t consider your email junk; and, after all, these subscribers did opt in at one time. But it is your responsibility to periodically cleanse your list of inboxes that subscribers have abandoned.


The best way to deal with these issues is to never have them to begin with. You need a re-engagement strategy. At minimum, you need a win-back campaign after subscribers have not opened or clicked in a certain amount of time.

A year ago, I would have recommended about six months as the maximum period of unengagement before you take action, but with the changes in algorithms from the ISPs in the last six months, I now recommend retargeting subscribers after just three to four months of unengagement.


The primary objective of a win-back campaign is for the subscriber to open. Once a subscriber opens an email they are no longer considered unengaged. For this reason, the subject line is a critical element to the win-back campaign. In this example from Bath & Body Works the subject line reads: We’ve Missed You! $1 Shipping – Today Only! Details Inside.

Bath Body Works Winback


Once the subscriber has opened the email, your call-to-action should be clear. Ideally, you would receive a click-through confirmation of the subscriber reaffirming their desire to continue to receive emails.

However, even if they are not interested, you would prefer for the subscriber to opt-out to be removed from the list. This prevents you from recycling the subscriber back into the win-back series later, and also prevents the possibility of the subscriber clicking “report spam” in their inbox, which can also lead to deliverability issues.

In this example from Crocs (a client at DEG, where I work), an unsubscribe link is clearly provided in the email.

Crocs Winback

What About The 95% That Didn’t Open?

Because these subscribers are already unengaged, your open rate on a re-engagement campaign will be low, and the majority of your subscribers will not open your message.

You are then faced with the decision of what to do with these subscribers. I recommend offering up to three direct re-engagement opportunities. You may include more incentives or deeper discounts in each email in the win-back series. If you still have radio silence, then it is time to part ways. This can be really difficult for some retailers, and I’ve heard many rebuttals, including:

“But they might open eventually.”

This is, at best, unlikely. If they haven’t opened in three months they probably aren’t going to open in the next three months. I’ve stopped receiving emails from brands I still love, and it’s probably because I didn’t open for just a few months. That’s why it’s imperative that you offer an option for subscribers to re-opt in on your site.

“Maybe they saw the email and purchased in store.”

This is possible, since an open is not recorded unless the user downloads images. Remember, just because the subscriber is unengaged with email does not mean they are unengaged with your brand. Be sure to collect a valid email address at POS in store and confirm their choice to opt-in.

“My product lifecycle is longer.”

This can be a valid point. After all, how often do you really buy a car? Or jewelry? Or concert tickets? This is where data really matters, to create relevant communications and key inflection points in the consumer lifecycle.

Who Is Worth Saving?

I recommend running your unengaged subscriber list through your data model of profitable customers to identify those worth attempting to save. For these subscribers, you should be able to identify potential triggers so that you may include more relevant content in the win-back emails. You may also choose to send a direct mail campaign with a call-to-action to go to a landing page to opt-in for email.

Only You Can Prevent Unengagement

In all of your email communications, commit to send more relevant emails. Be more strategic about your emails. Email has a high frequency and can be easy to churn through. Rewrite that subject line again. Have a fresh set of eyes review the creative concept. Ask yourself what content in the email should be dynamic based on previous subscriber behavior.

Create a testing plan for each campaign. Document the results. Ask yourself why a subscriber should stay on your email list. What is different now from what you were sending a few months ago? A year ago? Make each email better than the last. Challenge yourself and your team!

Identify behavior patterns from the time a subscriber signs up. Monitor their opens, click-throughs and conversions, altering subsequent email communications based on that data. This can help determine when and what to send as part of your win-back series.

Opinions expressed in the article are those of the guest author and not necessarily Marketing Land.

Related Topics: Channel: Email Marketing | Email Marketing | Email Marketing Column | Statistics: Email Marketing


About The Author: is Director of Digital Direct/eCRM at DEG, a full-service digital consultancy based in Kansas City. Leveraging her 14 years of experience and thought leadership in digital direct marketing, she and her team lead email and SMS strategy, integrations, and campaign execution for flagship brands like Crocs, Helzberg Diamonds, MathWorks, Cabela's, Life is Good, and TITLE Boxing. In her spare time she runs half marathons, cheers on her beloved Royals, and drinks copious amounts of coffee while trying to exhaust her eight year-old daughter, five year-old boy, and one year-old golden retriever.

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  • http://twitter.com/sammmer Sam Mazaheri

    Very interesting article and some great new content. Keep it coming Cara!
    One question: Why would an ISP “hold” an email for delayed delivery if engagement metrics are poor? How would delayed delivery benefit the user?

  • http://twitter.com/EmailGirl Cara Olson

    Thanks for the question, Sam. An ISP may delay delivery of an email to ensure other “more important” emails (marketing emails with higher engagement metrics, emails directly from friends and family, emails that you presumably want more) are delivered first. This becomes more common during high volume periods, like Black Friday and Cyber Monday. Let me know if you have any other questions! Cara


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