The Great Debate: Inactive Email Subscribers - To Send or Not to Send



A few weeks ago I came across a very interesting LinkedIn chain, started by Jordie Van Rijn, filled with innovative email experts that references an article by Steve Henderson, “Inactive Contacts in Email Marketing”. 

I was intrigued by the amount of opinions people had on this simple topic. Email has been around for a long time and I think what makes this industry so interesting is the ongoing discussion of topics just like these.

What I love about email marketing is that no matter how many days go by, or what side of the debate you are on, email marketing challenges us every day. There are always new things to learn. 

I thought it would be fun to gather a few email and deliverability experts to settle this debate and see what their thoughts were on whether to send or not to send to inactive email subscribers.

Here is what they had to say.




Dr. Ada Y. Barlatt

Founder of Operations Ally


To send or not to send -- actually, it depends! From my perspective, when it comes to the inactive subscribers on your list, I recommend you focus on carefully defining an inactive subscriber.  Incorrectly labeling a subscriber as inactive comes with risks no matter whether you decide to send emails to them or not.

If you aggressively label subscribers inactive and decide "not to send," you may remove interested people from your list. If you aggressively label subscribers inactive and decide to "send," you may turn off interested subscribers with frequent re-engagement emails. If you are too relaxed when labeling subscribers inactive, you risk deliverability issues (regardless of your decision to "send" or "not to send").

So how do you know what criteria to use to identify inactive subscribers on your list? Unfortunately, the criteria to pinpoint an inactive subscriber are different for every organization. To find the best answer for your program, I recommend understanding the distribution of time between key subscriber actions. 

If the word "distribution" is scary to you, focus on answering important questions about the duration between key steps in your customer journey -- e.g., how long is a subscriber typically on the list before they convert? Or what is the typical duration between purchases for subscribers?

You can use your historical data about the time between key actions (in conjunction with anti-spam laws) to guide your decisions on who to label as inactive, when to send re-engagement campaigns and when to stop sending.



Daniel Deneweth 

Head of Email Deliverability Services at Oracle Marketing Consulting


I understand the attraction. Inactive email subscribers represent people who expressed interest in your products or services at some point in the past. They were interested enough to sign up, right? Perhaps they’re just waiting for the right offer, and then they will spring to life. Maybe for the past six months, they’ve been backpacking through Europe, in the hospital, or writing the Great American Novel in a cabin in the woods. But now they’re back home, and ready to shop again. 

Wishful thinking is not an effective strategy when it comes to managing inactive subscribers. The decisions you make relative to your contact strategy and inactive email addresses can have a profound impact on the effectiveness of your email marketing programs. 

What may start out as just being cautious—making sure you don’t give up on someone too soon—can become a lethal anchor that drags down your email performance. Continuing to hold out hope these people will engage is a form of selective blindness. So far, you’ve probably sent these people dozens, if not hundreds, of email messages and they haven’t responded to any of them. Face facts: they are not interested. Or worse, the email address was originally mistyped. It could now be a spam trap or owned by someone else who does not appreciate receiving your emails. Many people will sign up using a secondary email address and never respond to the emails you send them. 

Take a look at the small value actually being derived from this inactive audience segment, and then compare that with a chronic degradation of your email marketing performance from reduced deliverability. You will likely find the benefits don’t come close to outweighing the costs and risks of sending to inactive subscribers. To continue sending to inactive subscribers at the cost of reduced deliverability performance is to fall for fool’s gold. 

I’m not saying to never send to less active or even inactive subscribers. A well-considered strategy with selective, occasional touchpoints can be effective. Overall, reducing the amount of emails you send to inactive subscribers will improve your deliverability health. However, anytime you send to inactive subscribers, you need to be very selective. Give up on any wishful thinking these inactive subscribers will suddenly surprise you with interest. Study your performance data, and then let the cost-benefit analysis guide your decision-making.


Komal Helyer

Fractional CMO


Many marketers believe that you should remove your inactive subscribers from your list. After all they could be damaging your deliverability and inbox placement. But I say, just hold on a minute! Ever subscriber is a potential source of revenue. So let’s not give up without a fight!

These subscribers are on your list for a reason. They were engaged with your brand once, there is no reason why you can’t re-engage them again. There’s a great 3 step process you can take to reignite the spark between your brand and the different types of inactive subscribers.

  1. Identify them. Not all inactives should be treated equally.
  2. Unengaged – these were once active and engaged but have recently stopped.
  3. Zombies – These were once very active – but have not engaged in a really long time
  4. Never actives – They signed up to your newsletter, but have never engaged since
  5. Segment and personalise
  6. Unengaged – focus on this segment and get a re-engagement campaign set up. These could be personalised product recommendations, competitions, discounts and reminders.
  7. Zombies – This segment need to be treated differently. We miss you campaigns, feedback surveys or even a reminder of your preference centre are great ways to re-engage at this stage.
  8. Never actives – This bunch of subscribers really should be taken out of regular mailings, where frequency is reduced. But before you do a last chance message could be sent to advise their frequency is going to reduce
  9. Regularly review and automate

An inactive subscriber programme needs to be automated into your marketing automation platform where the above programmes are automated when they slip into the different cohorts. 



Jeanne Jennings

Email Optimization Shop, Only Influencers, Email Innovations Summit



Inactive email subscribers may still be actively engaging with your brand in other channels. And email has what I think of as a ‘billboard effect’ – a strong subject line (think “25% off all shorts, today only”) from a brand you like can drive action (thinking visiting their website or a brick-and-mortar store) even if there’s no open or click. 

But there are a few things you have to do… 

First, if people aren’t engaging with your email messages it’s a good idea to decrease your frequency. This will do two things. 

It will save you some money if you are paying your send solution on a per-message-sent model. And it will show respect for those recipients who are no longer opening your emails – it could help encourage them to reactivate in the future.  

If you’re sending your inactives daily emails, knock back to once-a-week. If you’re sending weekly, drop back to monthly. If you’re sending monthly, perhaps it’s time to move to quarterly. 

If an inactive engages with a click (since opens aren’t an accurate granular metric), then you can move them back to the active file. 

Second, shift those inactive subscribers to a separate IP address. This group presents a higher risk of spam complaints, which could get you blocklisted, so you want to keep them away from your active subscribers and other communications with lower-risk audiences. 

Years ago, I tackled this issue with a large toy company that was a client of mine. Convention wisdom back then was to stop mailing to inactives. But the team’s bonuses depended on the size of their mailable email list, so that wasn’t an option. The steps we took there have informed my recommendations on inactives ever since. Here’s a blog post where I provided some tips based on that experience.  



Magan Le

Email and Lifecycle Marketing, Bolt 


Whether or not to send to inactive email subscribers isn’t a simple yes or no answer. Sometimes people see your subject line, but instead of engaging with your email, they take action elsewhere. But that email was still helpful, serving as a nudge or friendly reminder to do something with your brand they may not have done otherwise.
Duolingo is a great example of this. Every time I see their reminder in my inbox, I’m like, “Oh shoot, I forgot to do my daily language lesson,” and go straight to opening their app. Their emails do have a button that also takes you to the app, but I never click that. I don’t even open the emails anymore because the subject line tells me all I need to know (and I love that they add variety to it so it doesn’t get stale).
So, outside of email engagement, there are two other main considerations for emailing inactive subscribers: conversion activity and each subscriber’s sales/activity cycle.
A subscriber may appear to be not engaging with your emails, but do they still buy from you or use your services? If so, while they may not be an active email subscriber, they’re still an active customer and may be worth sending emails to.
And maybe some people buy once a year, like during Black Friday, while others buy once a month. But if you based inactivity on the monthly customer and stopped emails after just two months of non-engagement, you’d be missing out on a big chunk of your audience.
I’m not saying you should continue emailing your inactive subscribers as if they’re fully engaged. Dial down your email frequency. I always like to recommend at least a monthly cadence to stay top of mind.


At the very least, you need to give people a chance to stay informed before you stop sending to them forever. Many folks are just waiting for that right thing and/or that right moment but don’t want to forget that your brand exists for when that specific need arises—even if it’s years later.


Of course, there are also legal thresholds you need to comply with, such as no longer emailing someone with implied consent if it’s been two years since your business relationship existed or six months since their last transaction (CASL). Be sure to consult your lawyer on this as well.

Tejas (1)

Tejas Pitkar

Outbound Marketing Strategy for Hurix Digital.


The old-school approach would have been cleansing your list of cold recipients and saying goodbye. I think today’s approach to email marketing needs to differ. If you take the traditional approach, that’s leaving a lot of money on the table. 

The key to dealing with inactives is knowing the type of content they require from you with the right frequency and sending it at the right time.

  • The at-risk users that have recently gone cold (opens, no clicks, non-opens) need to be targeted with re-engaging content or offers. Get them to notice your emails again. 
  • The dormant users (longer-term non-opens) need to be amped down with their frequency. If you are mailing them every week, switch down to every month. Send them informative content, surveys and ask them if they prefer to reduce your messaging. 
  • The chronic cold users (no opens right from the start) can be re-engaged for at least 6 months. If they still don’t show any level of engagement, convey that they will be removed from the list due to inactivity. Gmail recommends doing so. 

I have observed re-engagement campaigns working magic to get customers interested in the company again, especially in B2B emails. I have seen subscribers respond even 3 months post a re-engagement workflow has finished.

So, don’t give up.  

In the long-term, it’s more cost-effective to deal with current customers than it is to acquire new ones.

Word of caution: During the re-engagement activity, monitor your deliverability and spam complaint rates. Gmail presents users with the option to one-click unsubscribe from emails they don’t check often.

Wrapping up:

Treating your inactives is a necessary part of your list hygiene. Make sure to segment your inactive like above and send them the right content at the right times. 

When re-engaging your subscribers, keep in mind:

  • Provide the right incentives for them to return
  • Tune your frequency to avoid annoying them with too many emails.
  • Show the subscribers what they miss about your company.


Tanya Plaza 

Deliverability and Messaging Operations Director at dotdigital


Should email marketers continue to send to their inactive subscribers? Short answer: yes, but it depends on how the business you’re sending for defines inactives. When I see this question answered by a prescribed formula telling marketers that there’s a number of days of inactivity that should be used, it causes me to cringe. I think about the KPI’s that are being left on the table or the recipients who are receiving unwanted messages. When a blanket policy of removing permissioned recipients after 60 days… 90 days… 120 days…. whatever the time frame is used, it’s likely causing some harm to the business -  it could harm recipient trust and ultimately deliverability, or it could be harmful to revenue or have other intended successes from sending email. Every business has a unique conversation with the human beings that have signed up to hear from them. There’s a lifecycle with signals that can be used to build a roadmap for getting the best success from sending email while respecting those individual’s want to hear from the business sending them emails. 

What are the signals marketers should look out for? Opens and clicks have long been top of mind, but recently the accuracy of these have been questioned more than ever. There are many blogs and conversations discussing their relevance in a rapidly changing ecosystem so I won’t get into it here. What I will say is that opens and clicks still fit into the overall holistic patterns that should be used to measure the effectiveness of an email. It’s about identifying the trends and using them along with any other metric at a marketer’s fingertips. What are some of the other signs? Product or customer lifecycle, revenue or other KPI, purchases, purchase history, bounces, complaints, unsubscribes, interactions with the brand in other ways - as many data points that can be looked at (don’t to forget to analyze negative indicators as well as positive ones.). Use those signs to identify timeframes - at what point is the potential for success of sending to that inactive recipient outweighed by the risk of not reaching the fans in your audience that show they want to hear from you and are adding to your success? Build a re-engagement strategy that treats recipients differently before reaching that point - and then stop sending to that recipient all together. 

To sum it up - yes, there is value in sending to inactive recipients IF there is a strategy in place to make sure wanted email is being sent. 



Matthew Vernhout 

VP, Deliverability Netcore Cloud - 



Determining when a subscriber is inactive is a tough choice for a lot of brands, and what to do with them as they reach the end of that relationship is an even harder decision by many brands. It often varies from vertical to vertical as well. A retailer may look at their data and say - this subscriber is still shopping with us, but no longer reads our emails - are they inactive? A publisher may look at their email lists differently and say list size is our KPI and we need to keep everyone that has ever subscribed on the list, only to find that over time delivery issues arise due to low engagement rates. 

So what’s the answer? “It depends”... 

Try changing the cadence of your messages to less active subscribers with a step down approach. For example a brand with daily mailings becomes weekly summaries after 30 or 60 days of inactivity. After another 4 or 8 consecutive mailings, they become monthly recipients for 2 months with different types of content at different intervals to keep your brand in mind. But after 6 months of being unengaged (or ~70 messages) it’s likely a good time to say goodbye and send a sunsetting email, inviting the recipient back at a better time for them. In a similar fashion if you mail less frequently you’ll likely need to look at a smaller number of messages to make that determination and offer a similar step down in frequency. 

Now do you really need to do all this work? Maybe… If you’re not seeing significant issues with delivery to the inbox you likely don’t need to make significant changes to your email program. However, with engagement being an important part of the Machine Learning algorithms at Mailbox providers to decide on inbox or spam filter placement you’ll need to work and identify the ideal cutoff time frame and make adjustments that work best for your audience. 



Sella Yoffe

Email Deliverability & Email Marketing Consultant, CEO @ DATAMEDIA.CO.IL, Blogger & Podcaster @ CRM.BUZZ


Some marketers think it’s a known “best practice” that you should purge inactive subscribers from your sending lists after X or Y month of inactivity.

You may even doubt the correct answer when you realize that some ESPs will highlight unengaged subscribers, and some even make it difficult for you to send them emails.

The short answer is: you don’t have to delete inactive subscribers from your lists. You can keep sending them emails, but you need to do so with your hands on the wheel and your eyes on the road. Otherwise, you may hurt your deliverability. 

By “keeping your eyes on the road,” I mean monitoring your subscribers’ behavior by dynamically assigning them engagement scores based on their activity (their level of engagement over time).

Ask yourself: why are they inactive? Do I have deliverability issues?.If so, there is no surprise that they are dormant. They may not have received your emails.

Are they active on other channels (call center, store visits, website visits, etc.)? Can I measure or detect that engagement (do I have the data)? 

Are you doing your best to catch your subscriber's attention in their already bloated mailboxes by crafting creative headlines? 

Are you A/B/C testing headlines, and sender names? 

Are you  sending too many promotional emails? Do you bring valuable content to your consumers with your emails or are you just trying to sell them? 

What else can you do instead of purging inactive subscribers from your lists? 

Continue sending to a small portion of your inactive subscribers with every campaign sent to your engaged subscribers. If you have deliverability issues caused by low engagement, over time, “riding the wave” of good engagement will likely help you reach inactive subscribers. Go slow, be patient, don’t over mix inactive and active subscribers on the same campaign. Monitor your good and bad metrics, then adjust when needed. 

There are other methods and approaches to explore, like using different ESPs for inactive subscribers, or using external tools. 

Think outside the (mail)box. You may want to try to revitalize your inactive subscribers by using other channels, like SMS, or custom audiences. Based on your inactive subscribers’ lifetime value (LTV), you may want to use expensive direct mail to re-engage inactive subscribers.

Verify, Protect and Grow Your Database