The Sunset Flow: Protect Your Deliverability on Purpose

Unengaged Subscribers Do More Harm Than Good

Every email you send to someone who stopped opening is a vote against your own domain.

Google scores you on engagement rate, not list size. When a big chunk of your list ignores you, that ignoring becomes your reputation, and your best customers start landing in spam because of people who will never buy again.

The sunset flow is how you cut that dead weight on purpose. It gives quiet subscribers one last shot to raise their hand, then quietly stops mailing the ones who don't.

Email and SMS have been our whole focus for the past five years. Last year we drove over $20 million for our clients from these two channels alone, and list hygiene is a big part of why. You cannot scale sends on a rotting list.

Here is what the sunset flow does and why it lifts inbox placement for everyone else.

Define "Unengaged" Before You Do Anything

You cannot sunset people until you decide what counts as dead.

Start by looking at where your list actually sits. Build engaged segments for 30, 60, 90, 180, and 365 days. A 30-day engaged segment is everyone who opened or clicked an email in the last 30 days. Do that at every window and you can see exactly how many real subscribers you are working with.

The pattern is always the same. The 30-day segment is packed with your most engaged people. By the time you get to 180 and 365 days, engagement falls off a cliff. Now you know what you are dealing with.

The rule is simple. Unengaged means no opens and no clicks in your chosen window. Most brands use 90 to 180 days. If someone opened or clicked once in that window, they are still alive and they stay out of this flow.

1. Pick your window. 90 days for a high-frequency list, 180 for a slower one. Match it to how often you send.
2. Require zero opens AND zero clicks. One click keeps them engaged. You are only sunsetting true silence.
3. Exclude recent buyers. Someone who purchased last month but never opens still counts as engaged. Do not sunset a paying customer.

The hardest cases to be honest about are the true dead weight: no engagement at all in the last 365 days, and on the list for over a year. These are the people you have to decide on. They are not opening, they are not clicking, and they have had plenty of time to. Send to them and you are voting against your own domain every single time.

This is the same engagement window logic your tiers run on. We send almost every regular campaign to the engaged segments only. If someone is not in an engaged segment, they are not getting the everyday sends. The sunset flow is just the bottom tier finally aging out.

The Last-Chance Sequence

Do not suppress people cold. Give them one clean chance to come back first.

This is a short flow. Two or three emails, no fluff, then a decision.

Anyone who engages proves they still want you, and they earn their spot back in your active list.

Everyone else gets suppressed, and that is the whole point.

Make opting out the easy path. Do not bury the unsubscribe link at the bottom. Put a message near the top in big bold red text: if you want off this list, click here, that is totally fine. It feels counterintuitive, but it is mutually beneficial. A person who clicks that link instead of hitting the spam button just handed you clean data and protected your reputation at the same time. You would much rather they opt out than mark you as spam.

Batch your sends. On a big list, do not fire the whole re-engagement series at everyone at once. Break it into smaller batches spread over a longer window. Dumping thousands of low-engagement sends in one day is exactly how you tank your deliverability while trying to save it.

Watch your metrics as it runs. Open rate, click rate, bounce rate, unsubscribes, and spam complaints. You are aiming for at least a 10% open rate. On any normal campaign 10% would be terrible, but this is a winback audience you touch rarely, so treat 10% as the floor and anything below it as a warning sign.

In Klaviyo the cleanup is fast. Build a segment of the people who stayed silent, then bulk suppress that whole segment in one action. There is no reason to do this by hand.

Why Cutting Dead Weight Lifts Everyone Else

This is the part brands get wrong. They think removing subscribers shrinks their reach.

It does the opposite.

Engagement is a rate. When you stop sending to the silent half, your open and click rates climb, and Google reads that as a stronger sender. Better sender reputation means your live campaigns land in the inbox for the people who actually buy.

You are not losing revenue when you sunset. You are protecting the inbox placement of the customers who fund your business.

A smaller list that opens beats a bloated one Google has learned to filter, every time.

Where It Sits With Tiers and Winback

The sunset flow is not a standalone trick. It is the last stop in a system.

Winback is the gentle nudge. The sunset flow is the final decision after that nudge fails.

The winback flow itself runs off the placed-order metric. Someone bought, then a long stretch passed with no second order, and the flow fires automatically with your best offer to pull them back. We build this for clients constantly and it crushes.

The one thing you cannot copy from another brand is the winback window. It depends entirely on your product and your sales cycle. A seasonal fashion brand might not consider someone lapsed until two years of silence. A supplement on a 30-day refill cycle should be chasing them again inside 90 days. Set the window to your buying rhythm, not a generic number.

Run these in order. Tiers keep your engaged people happy, winback catches the ones slipping away, and the sunset flow clears out whoever is truly gone so your reputation stays clean.

Then keep it running. We audit engaged segments and suppress the newly dead on a quarterly cadence. A bigger or faster-growing list might need it monthly. The point is that this is a habit, not a one-time cleanup, so the list never rots again.

Common Mistakes

1. Deleting instead of suppressing. You lose the data and can never run a future winback. Always suppress.
2. No last-chance sequence. Cutting people with zero warning skips your best re-engagement send. The "removing you tomorrow" email brings a chunk of them back.
3. Sunsetting on opens alone. A single click is engagement. Require no opens AND no clicks before anyone qualifies.
4. Including recent buyers. A customer who purchased but never opens is still paying you. Exclude them from the flow.
5. Running it once and forgetting it. Make it a live, always-on flow so the list never rots again.
6. Treating it as lost revenue. The silent were not buying anyway. Suppressing them protects the inbox for the people who are.

Get Expert Help

A clean sunset flow is the difference between a list that grows your revenue and one that quietly drags you into spam. Our team builds the engagement windows, the last-chance sequence, and the suppression rules so your best customers keep seeing your mail.

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