Why You Need a Sunset Flow (And How to Build One That Doesn't Kill Your List)

Let me tell you about the most counterintuitive thing in email marketing: the flow that makes your list smaller actually makes you more money.

That's the sunset flow. And it terrifies most eCommerce brands.

The logic goes like this: "Why would I suppress people from my list? More subscribers equals more revenue, right?" Wrong. Dead wrong. And I can prove it with your own Klaviyo data.

At GOSH Digital, we've built sunset flows for 150+ brands. Every single time -- every single time -- deliverability improves, open rates jump, and revenue per email goes up. You make more money by emailing fewer people. Here's exactly how it works and how to build one without accidentally destroying your list.

What Is a Sunset Flow?

A sunset flow is an automated sequence that identifies subscribers who've stopped engaging with your emails and gives them one final chance to re-engage before you suppress them from future campaigns.

Think of it as a last call before you stop spending money emailing people who aren't listening.

The key word there is "suppress" -- not "delete." You're not removing them from Klaviyo. You're moving them to a suppressed segment so they stop receiving campaign emails. They can still trigger flows (like abandoned cart) if they come back to your site. But your regular campaigns? They stop going to dead weight.

Why You Can't Skip This

Here's what happens when you don't have a sunset flow:

Your Deliverability Tanks

Gmail, Yahoo, and Outlook are watching your engagement metrics. When a large percentage of your emails go unopened, mailbox providers interpret that as a signal that your content is unwanted. The result? More of your emails land in spam -- including the ones going to engaged subscribers who actually want to hear from you.

We audited a fashion brand last year that had 85,000 subscribers and was seeing 12% open rates on campaigns. After building a sunset flow and suppressing 31,000 unengaged subscribers, their open rates jumped to 28% -- and their campaign revenue increased by 40%. More revenue. From fewer people.

Your Costs Go Up

Klaviyo charges based on the number of active profiles. If you have 50,000 profiles but only 20,000 engage with your emails, you're paying for 30,000 profiles that contribute nothing. That's real money. Depending on your plan, suppressing unengaged profiles could save you $100-300/month.

Your Data Gets Unreliable

When half your list is unengaged, your A/B test results are skewed, your campaign metrics look worse than they are, and you can't tell what's actually working. Clean data leads to better decisions.

The Fear Factor: "But What If I Suppress Someone Who Would Have Bought?"

This is the number one objection. And it's valid -- to a point.

Here's the data: across 150+ accounts we manage, the percentage of revenue attributed to profiles who hadn't opened or clicked an email in 180+ days is consistently under 1.5%. Usually under 1%.

That means 99% of your email revenue comes from people who've engaged with your emails in the last 6 months. The other 1% isn't worth destroying your deliverability over.

And remember -- suppressed profiles can still re-engage through flows. If they visit your site and add to cart, they'll trigger the abandoned cart flow. If they make a purchase, they'll trigger the post-purchase flow. Sunset suppression only affects campaigns. It's not a death sentence.

The Exact Sunset Flow: 3 Emails + 1 SMS

Here's our go-to sunset flow structure. Simple, effective, and safe.

Step 0: Define "Unengaged"

You need a Klaviyo segment for unengaged subscribers. Here's the definition we use:

Segment conditions:

• Has received at least 10 emails in the last 90 days
• Has NOT opened any email in the last 90 days
• Has NOT clicked any email in the last 90 days
• Has NOT placed an order in the last 120 days
• Has NOT been active on site in the last 60 days

Why these conditions matter:

• "Received at least 10 emails" ensures they've had enough chances to engage. Don't sunset someone who only got 2 emails.
• The 90-day window is our default. For luxury or long-cycle brands, extend to 120-180 days.
• The "active on site" condition catches people who visit your site but don't open emails -- they're not truly unengaged, they're just email-averse.
• The "placed an order" condition prevents you from sunsetting recent buyers.

Email 1: The Re-Engagement Ask (Day 0)

Subject line: "Do you still want to hear from us?" or "We noticed you've been quiet"

Content:

• Be direct. "We've noticed you haven't opened our emails in a while."
• Ask a simple question: Do you still want to hear from us?
• Two clear buttons: "Yes, keep sending" and "No, unsubscribe me"
• Mention what they're missing: "We've launched 12 new products since we last heard from you"
• No discount. This isn't a win-back. This is list hygiene.

Why honesty works: People respect transparency. And the "Yes, keep sending" button click tells Klaviyo (and Gmail) that this subscriber is engaged. It literally improves your sender reputation.

Email 2: Show Them What They're Missing (Day 4)

Subject line: "Last 3 things you missed" or "Before we go..."

Content:

• Curated highlight reel: your 3 best-performing products, top blog posts, or biggest wins from the last 90 days
• Make it visually compelling. Big images. Bold stats.
• Social proof: "Over 2,000 customers loved this product last month"
• CTA: "I want to stay" or "Show me more"
• Secondary CTA: "Unsubscribe" (don't hide it -- make it easy)

SMS 1: The Direct Line (Day 5)

Message: "Hey [first_name], we're about to stop emailing you since you haven't opened any in a while. Want to stay on the list? Tap here: [link]"

This catches people who genuinely don't check email but are reachable via text. We see 15-20% click rates on sunset SMS.

Email 3: The Final Email (Day 7)

Subject line: "This is our last email to you" or "Goodbye (unless you say otherwise)"

Content:

• Make it emotional but not manipulative. "We don't want to clutter your inbox if you're not interested."
• One final CTA: "Keep me on the list"
• Explain what happens: "If we don't hear from you, we'll stop sending campaign emails. You'll still get order confirmations and account emails."
• Final incentive (optional): "As a last thank you, here's 15% off if you'd like to come back."

After Email 3: Anyone who didn't click "keep me" in any of the three emails or the SMS gets added to a "Sunset Suppressed" segment.

Setting Up the Suppression

Here's the critical part -- what happens after the flow.

Create a "Sunset Suppressed" Segment

Conditions:

• Has completed the sunset flow
• Has NOT clicked any email in the sunset flow
• Has NOT clicked the SMS in the sunset flow
• Has NOT placed an order in the last 30 days (safety catch)

Exclude This Segment From All Campaigns

When you send campaigns in Klaviyo, add the "Sunset Suppressed" segment to your exclusion list. Do this for every campaign. Or better yet, add it to your default campaign exclusion list so you never forget.

Don't Suppress From Flows

This is important. Keep sunset-suppressed profiles eligible for triggered flows (abandoned cart, browse abandonment, post-purchase, win-back). If they come back to your site and show buying intent, you absolutely want those automations to fire.

Set a Re-Entry Window

After 90 days, re-evaluate the suppressed segment. Some brands run a quarterly "re-engagement" campaign to the suppressed list -- one email with a strong offer. If they engage, they re-enter the active list. If they don't, they stay suppressed.

The Numbers: Before and After Sunset

Here's what we typically see when a brand implements a sunset flow:

| Metric | Before Sunset | After Sunset | Change | |---|---|---|---| | List size | 50,000 | 32,000 | -36% | | Average open rate | 14% | 27% | +93% | | Average click rate | 1.2% | 2.8% | +133% | | Campaign revenue/send | $2,400 | $3,350 | +40% | | Spam complaint rate | 0.08% | 0.02% | -75% | | Gmail inbox placement | 72% | 94% | +31% |

Look at those numbers. The list got 36% smaller but campaign revenue went up 40%. That's the power of deliverability.

How Aggressive Should You Be?

This depends on your list size and current deliverability health.

Conservative approach (recommended for most brands):

• 90-day engagement window
• 3 sunset emails over 7 days
• Include site activity and purchase history in segment conditions
• Quarterly re-engagement attempts for suppressed profiles

Moderate approach (for brands with known deliverability issues):

• 60-day engagement window
• 3 sunset emails over 5 days
• Suppress after the flow completes
• Bi-annual re-engagement attempts

Aggressive approach (for brands in deliverability crisis):

• 30-day engagement window
• 2 sunset emails over 3 days
• Immediate suppression
• Consider using a list cleaning service like ZeroBounce or NeverBounce first

If you're landing in spam for a meaningful percentage of your list, start aggressive and ease up once deliverability stabilizes.

Common Mistakes to Avoid

1. Not Excluding Recent Purchasers

Always add a condition that excludes anyone who's placed an order in the last 120 days. Some customers buy from you but never open emails -- they find you through Google, bookmark your site, or use the app. Sunsetting a paying customer because they don't read emails is a terrible idea.

2. Making Unsubscribe Hard to Find

If someone wants to unsubscribe, let them. A clean unsubscribe is infinitely better than a spam complaint. Spam complaints destroy your sender reputation. Unsubscribes don't.

3. Sunsetting Too Early After List Growth

If you just ran a big promotion or BFCM campaign that grew your list significantly, wait at least 60-90 days before running sunset on the new subscribers. Give them time to settle into their engagement pattern.

4. Forgetting to Exclude the Sunset Segment From Campaigns

This defeats the entire purpose. If you build a beautiful sunset flow but forget to exclude the suppressed segment from campaigns, nothing changes. Add it to your default exclusions.

5. Not Tracking the Impact

Set up a custom report in Klaviyo that tracks your deliverability metrics week over week. Compare open rates, click rates, and revenue per email before and after sunset implementation. You need this data to prove the flow is working and to calibrate the aggressiveness of your suppression.

The Setup Checklist

• [ ] Defined your engagement window (60/90/120 days based on brand)
• [ ] Created "Unengaged" segment with proper conditions
• [ ] Email 1 asks directly if they want to stay
• [ ] Email 2 shows what they're missing
• [ ] SMS reaches the email-averse
• [ ] Email 3 is a clear "last email" with final CTA
• [ ] Created "Sunset Suppressed" segment based on flow completion + no clicks
• [ ] Added suppressed segment to campaign exclusion list
• [ ] Flows remain active for suppressed profiles
• [ ] Re-engagement cadence planned (quarterly recommended)
• [ ] Deliverability tracking dashboard set up
• [ ] Recent purchasers excluded from sunset segment

The Bottom Line

A sunset flow doesn't shrink your revenue. It protects it. Every unengaged subscriber you keep emailing drags down your deliverability, which drags down your inbox placement, which drags down your revenue from the subscribers who actually want to buy from you.

Think of it like pruning a tree. You cut the dead branches so the healthy ones can grow.

Get Your List Health Checked for Free

We'll look at your Klaviyo account, identify your unengaged segment size, estimate the deliverability impact, and build you a sunset flow plan. Takes 20 minutes. No obligation.

Book your free Klaviyo audit.

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Mark Cijo is the founder of GOSH Digital, a Klaviyo Gold Partner agency that's driven $23M+ in revenue for 150+ eCommerce brands. He believes the best email strategy is sending fewer, better emails to people who actually want them.