When to Let Subscribers Go: The Sunset Strategy

Here is something nobody wants to hear: most of your email list is dead weight.

Not "could be better." Not "needs a re-engagement campaign." Dead weight. People who signed up 18 months ago for a 10% discount, used it once, and have not opened a single email since.

And every time you send a campaign to those people, you are actively hurting the subscribers who actually want to hear from you.

Gmail, Yahoo, and every other inbox provider watches engagement signals. When a big chunk of your list ignores your emails, the providers start routing your messages to spam — for everyone. Including the people who love your brand and buy from you regularly.

This is why a sunset strategy is not optional. It is the single most important thing you can do for your email program that has nothing to do with writing better subject lines or designing prettier templates.

Why Your List Size Is a Vanity Metric

I have talked to store owners who are proud of their 80,000 subscriber list but only have a 12% open rate. That means roughly 70,000 people are ignoring every email. And those 70,000 silent subscribers are dragging down the deliverability for the 10,000 who engage.

Here is the math that matters:

• A 50,000 subscriber list with a 35% open rate reaches approximately 17,500 engaged people and has strong deliverability signals.
• An 80,000 subscriber list with a 12% open rate reaches approximately 9,600 engaged people and has weakening deliverability signals.

The smaller, cleaner list reaches more actual humans. The bigger, dirtier list costs more to maintain and delivers worse results.

Klaviyo charges based on profile count. Every unengaged subscriber you keep is money out of your pocket for zero return.

What a Sunset Strategy Actually Is

A sunset strategy is a systematic process for identifying subscribers who have stopped engaging with your emails and either re-engaging them or removing them from your list.

It is not sending one "we miss you" email and calling it a day. That is a re-engagement campaign, which is one step in the process.

A real sunset strategy has three phases:

1. Identification — Define what "unengaged" means for your brand and segment those subscribers
2. Re-engagement — Make a genuine attempt to bring them back with a focused sequence
3. Suppression — Remove anyone who does not respond from your sending list

The entire process runs on autopilot in Klaviyo once you set it up. You should never have to manually clean your list again.

Phase 1: Define Your Engagement Window

Before you can sunset anyone, you need to decide what "unengaged" means. This varies by brand and sending frequency.

If you send 3-5 emails per week:

Someone who has not opened or clicked in 60 days has had at least 36 to 60 opportunities to engage. That is enough data to call them unengaged.

If you send 1-2 emails per week:

Extend the window to 90 days. Fewer sends means fewer data points.

If you send less than weekly:

Use 120 days as your baseline. But also, you should be sending more frequently.

The definition also depends on your purchase cycle. If your product is a quarterly replenishment item, a 60-day window might be too aggressive. Adjust based on how often a customer realistically buys.

How to set this up in Klaviyo:

Create a segment called "Sunset Candidates" with these conditions:

• Has been on the list for at least 90 days (don't sunset new subscribers who haven't had time to engage)
• Has not opened any email in the last 60/90/120 days (pick your window)
• Has not clicked any email in the last 60/90/120 days
• Has not placed an order in the last 120 days (protect recent buyers even if they don't open emails)

That last condition is important. Some customers buy through direct links, bookmarks, or repeat orders without ever opening an email. You do not want to sunset someone who spent $500 last month just because they did not open your Tuesday newsletter.

Phase 2: The Re-Engagement Sequence

Before you remove anyone, give them a fair shot. Build a sunset flow in Klaviyo that makes three attempts to bring them back.

Email 1: "We noticed you've been quiet"

Send this when someone enters your sunset segment. Keep it simple and honest.

Subject: "Still interested in hearing from us?"

Body: Acknowledge that they have not engaged recently. Remind them what they signed up for. Give them a reason to stay — a discount, a new product, a content piece they might care about. Include a clear "Yes, keep me subscribed" button.

Email 2: "Last chance — here's something special" (5 days later)

For everyone who did not open or click email 1. This is your best offer. If a 20% discount or free shipping does not bring them back, nothing will.

Subject: "20% off — just for you"

Body: Lead with the offer. Make it time-limited. Include product recommendations based on their past browse or purchase history if available. One clear CTA.

Email 3: "We're removing you from our list" (5 days later)

For everyone who did not engage with emails 1 or 2. This is the "breakup" email and it is often the highest-performing email in the sequence. Loss aversion is real.

Subject: "We're saying goodbye"

Body: Tell them you are going to stop emailing them. This is not a threat — it is a courtesy. Give them one final button: "No wait, keep emailing me." Anyone who clicks stays. Everyone else gets suppressed.

Phase 3: Suppression

After the three-email sequence, anyone who did not open, click, or take any action gets suppressed.

Suppressed, not deleted.

In Klaviyo, you want to suppress these profiles rather than delete them. Suppression means they stay in your system (you keep their data, purchase history, and profile properties) but they are excluded from all future email sends.

Why not delete? Because if they come back to your site and make a purchase or fill out a form, they re-engage naturally. Their profile is still there, ready to be reactivated. Deletion means you lose everything.

How to automate this in Klaviyo:

At the end of your sunset flow, add a profile property update: set "Sunset Status" to "Suppressed" and add them to a suppression segment. Then exclude that segment from all campaigns and flows.

Alternatively, use Klaviyo's built-in "Suppress Profiles" action in the flow builder to formally suppress them at the platform level.

How Often to Run the Sunset Process

This should not be a one-time cleanup. Your sunset flow should run continuously.

Set the segment to update daily. As subscribers cross your engagement threshold, they automatically enter the sunset flow. This keeps your list perpetually clean without you ever having to think about it.

Run a manual audit quarterly to check:

• How many profiles are entering the sunset flow per month
• What percentage re-engage during the sequence
• Overall list health metrics (open rate, click rate, spam complaint rate)

If your sunset flow entry rate is climbing, it usually means your regular content is becoming less relevant or you are acquiring low-quality subscribers. Fix the root cause, not just the symptom.

The Deliverability Impact

Here is what typically happens in the 30 days after implementing a sunset strategy:

• Open rates increase by 5 to 15 percentage points
• Click rates increase by 2 to 5 percentage points
• Spam complaint rates drop below 0.1%
• Gmail placement rate improves (more emails land in Primary tab instead of Promotions or Spam)
• Revenue per email sent increases even though total sends decrease

We ran this exact playbook for an eCommerce brand doing $2M per year. Their list was 95,000 profiles with a 14% open rate. After sunsetting, the list dropped to 41,000 profiles. Open rates jumped to 32%. Revenue per campaign actually increased by 22% because more emails were landing in inboxes.

The list got smaller. The revenue got bigger. That is the power of a clean list.

The Emotional Hurdle

I get it. Watching your subscriber count drop from 80,000 to 40,000 feels terrible. It feels like you are losing something you worked hard to build.

But you are not losing anything. Those 40,000 people were not reading your emails. They were not buying. They were just a number on a dashboard that made you feel good while quietly sabotaging your deliverability.

Think of it this way: would you rather have 80,000 subscribers where 70,000 ignore you and the other 10,000 increasingly get sent to spam? Or 40,000 subscribers where 30,000 actually see your emails and buy from you?

The answer is obvious when you look at it in terms of revenue instead of vanity metrics.

Advanced Sunset Tactics

Segment by acquisition source:

Track where subscribers came from (popup, checkout, social ad, etc.) and analyze which sources produce the most sunset candidates. If 60% of your sunsetted profiles came from a specific Facebook campaign, that campaign is acquiring junk leads. Fix the targeting.

Test different re-engagement offers:

Not every audience responds to discounts. Some re-engage with exclusive content, early access to new products, or a simple "what do you want to hear about?" preference survey. Test different approaches in your sunset flow.

Channel-switch before suppressing:

Before you fully suppress someone from email, consider moving them to a lower-frequency channel. Add them to an SMS re-engagement flow or a direct mail campaign. Some people just do not engage with email anymore but might respond to a text message.

Win-back vs. sunset distinction:

A win-back flow targets people who have purchased before but gone quiet. A sunset flow targets anyone who has stopped engaging, regardless of purchase history. These should be separate flows with different messaging. A past customer deserves a different approach than someone who never bought.

Setting Up the Klaviyo Sunset Flow Step by Step

Here is the exact flow structure:

1. Trigger: Profile enters the "Sunset Candidates" segment
2. Wait 1 day (don't email them the instant they cross the threshold)
3. Email 1: "Still interested?"
4. Wait 5 days
5. Conditional split: Opened or clicked email 1?
   • Yes: Exit flow (they re-engaged)
   • No: Continue
6. Email 2: Best offer email
7. Wait 5 days
8. Conditional split: Opened or clicked email 2?
   • Yes: Exit flow
   • No: Continue
9. Email 3: Breakup email
10. Wait 3 days
11. Conditional split: Opened or clicked email 3?
    • Yes: Exit flow
    • No: Continue
12. Update profile property: Sunset Status = Suppressed
13. Add to suppression list

Total flow duration: approximately 14 days from entry to suppression. This gives every subscriber three genuine chances to stay.

Common Mistakes

Setting the engagement window too short. If you sunset people after 30 days, you will suppress a lot of subscribers who were just busy or on vacation. 60 to 120 days is the sweet spot for most brands.

No purchase protection. Always exclude recent buyers from your sunset segment. Email open tracking is not perfect. Some customers buy regularly without opening emails.

Running sunset as a one-time event. This needs to be continuous. A quarterly manual purge creates a rollercoaster of list quality instead of consistent hygiene.

Not tracking the re-engagement rate. If fewer than 5% of sunset candidates re-engage during the flow, your emails are not compelling enough. Improve the offers and copy.

The Bottom Line

Letting subscribers go is one of the hardest things to do in email marketing because it goes against every instinct. More subscribers should mean more revenue. But it does not work that way.

Email deliverability rewards quality over quantity. A clean list of engaged subscribers will outperform a bloated list every single time.

Set up the sunset flow. Let it run. Watch your open rates climb, your revenue per email increase, and your Klaviyo bill go down.

That is what winning looks like in email marketing.

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Need help cleaning up your list and building a sunset flow in Klaviyo? Book a free strategy call and we will audit your engagement data and build the flow for you.