What Is a Klaviyo Sunset Flow? How to Clean Your List (and Stop Paying for Dead Subscribers)

Somewhere on your list is a big group of people who have not opened, clicked or bought in months. You are still paying Klaviyo for every one of them.

That is what a sunset flow fixes. It is not glamorous, and it is one of the most valuable things you can set up this quarter.

What is a sunset flow, exactly?

A sunset flow, the automated “last chance” sequence for people who have gone cold, targets subscribers who have shown no sign of life for a set period. No opens, no clicks, no purchases, no site activity. Complete ghosting.

The flow sends a short run of emails. Anyone who re-engages gets pulled back into your normal list. Anyone who still ignores you gets suppressed, so you are no longer paying to email an inbox that is closed, full, fake or simply not monitored.

Think of it as spring cleaning for your list, except it also lowers your Klaviyo bill.

How long should someone be inactive before they get sunset?

The standard starting point is 120 or 180 days of total silence. No engagement of any kind in that window.

Which number you choose depends on your buying cycle. If people naturally repurchase every few months, 120 days might be right. If your product is a once-a-year kind of buy, 180 days is safer, so you do not sunset someone who was always going to take longer.

Look at your own data before you set it. The point is to catch genuinely dead contacts, not slow-but-loyal ones.

Why should a sunset flow be plain text?

This surprises people. Your sunset emails should be intentionally plain. No big designed header, no heavy graphics.

Here is why. These subscribers are already at risk of sitting in the promotions tab or the junk folder. A stripped-back, plain-text email that looks like a personal note has the best possible chance of landing in the main inbox, which is exactly where you need it to land to get their attention.

Pretty does not matter here. Getting seen does.

What do you actually say in a sunset flow?

This is your last hurrah, so make it worth their while. A strong sunset email usually pairs a bold, clickbait-style subject line with a real reason to come back.

Something like a genuine “here’s 20% off, 24 hours only” works because the discount is what stops the scroll for someone who has been ignoring you. You are asking a simple question: are you still there, or is this a dead inbox?

• A subject line that earns the open, often a discount or a direct “is this goodbye?”
• A short, warm, human message. No wall of design.
• A clear offer or reason to click, so any sign of life registers.
• An exit for the ones who do not respond. They get suppressed, not deleted forever.

Any click, open, purchase or site visit counts as re-engagement. Those people come back onto the list. The silent ones move on, and that is the whole idea.

Not sure how much of your list is quietly dragging down your results? A Mini Klaviyo Audit gives you a personalised look at what your account is actually doing: inflowmarketing.co/mini-klaviyo-audit

Does cleaning my list really help deliverability?

Yes, and it is one of the most underrated moves in email. Your sender reputation is partly built on how engaged your audience is. When you keep emailing people who never open, you look like a lower-quality sender, and more of your emails slide toward spam.

Remove the dead weight and your engagement rate climbs, because the people left are the ones who actually want you. Better engagement means better inbox placement for everyone on your list, including your best customers.

A smaller, engaged list will out-earn a big, half-dead one every time.

Sunset flow vs win-back flow: what’s the difference?

People mix these two up, and they do different jobs. A win-back flow, the sequence aimed at lapsed customers, targets people who have bought before but have gone quiet. It leans on the fact that they already like you, so it reminds them what they are missing.

A sunset flow goes a step further. It targets the truly disengaged, buyers and non-buyers alike, who have shown zero activity for months. Its goal is not really to win them back. Its goal is to find out if anyone is home, then clear out the ones who are not.

Think of it this way. Win-back says “we miss you.” Sunset says “last call, then we let you go.” You want both, aimed at different groups.

What happens to your account after you clean the list?

A few things shift, and they all point the same way.

• Your engagement rates rise. Not because you did anything clever with the content, but because the people ignoring you are gone. The percentages reflect the people who actually care.
• Your deliverability improves. Inboxes see a more engaged audience and trust you more, so more of your emails land where people will see them.
• Your Klaviyo bill can drop. Fewer contacts, especially if you were creeping into a higher pricing tier on the strength of dead weight.
• Your reporting gets honest. You are finally looking at numbers based on real subscribers, which makes every decision after that clearer.

None of this is dramatic on the day you do it. It is the quiet groundwork that makes everything else you send perform better.