You've been emailing 50,000 subscribers every week for two years. Open rates are tanking. Deliverability is circling the drain. And you're sitting there wondering why your "perfectly optimized" campaigns keep landing in spam.
Here's the uncomfortable truth: half your list stopped caring about you six months ago.
An email sunset policy fixes this. It's a systematic approach to identifying and removing subscribers who haven't engaged in months, which sounds terrifying until you realize those ghosts are actively destroying your sender reputation. Before you sunset, try a re-engagement campaign first.
What Is an Email Sunset Policy?
A sunset policy is a segmentation strategy that stops you from emailing people who stopped opening months ago. It's a core part of email list hygiene that most marketers ignore until it's too late.
Not complicated. You define a timeframe of inactivity, say 90 to 180 days of zero opens or clicks, and you either reduce email frequency to those contacts or remove them entirely.
The goal isn't to shrink your list for fun. It's to protect your deliverability. Gmail, Yahoo, and Outlook all track engagement signals. When you keep blasting emails to subscribers who never open, their spam filters notice. And they punish you.
According to Mailjet's 2026 deliverability report, senders who implement sunset policies see open rate improvements of 15 to 25 percent within 60 days. Not because the emails got better. Because they stopped sending to dead addresses.
Why Most Marketers Refuse to Sunset
I get it. You spent years building that list. Every subscriber feels like money in the bank.
Except they're not.
An inactive subscriber isn't a future customer waiting to be awakened by the perfect subject line. They're a weight dragging your entire program into the Promotions tab.
Here's what actually happens when you refuse to sunset:
| Metric | With Dead Weight | After Sunsetting |
|---|---|---|
| Open Rate | 12-15% | 25-35% |
| Spam Complaints | 0.3%+ | Under 0.1% |
| Inbox Placement | 70-80% | 90%+ |
| Sender Score | Declining | Stable/Improving |
Those numbers aren't hypothetical. I've watched brands double their effective reach by cutting their list in half.
Counterintuitive? Sure. But a 35% open rate on 25,000 engaged subscribers beats a 12% open rate on 50,000 ghosts every single time.
When to Sunset: The Timeline
The exact timeframe depends on how often you email and what you sell.
For weekly emailers (most e-commerce brands):
- 90 days no engagement: Reduce frequency to monthly
- 120 days no engagement: Send re-engagement sequence
- 150 days no engagement: Move to quarterly sends only
- 180 days no engagement: Unsubscribe or delete
For monthly emailers (B2B, SaaS):
- 6 months no engagement: Send re-engagement sequence
- 9 months no engagement: Final warning email
- 12 months no engagement: Remove from list
The pattern matters more than the exact days. You're giving people multiple chances to wake up before you cut them loose.
How to Build Your Sunset Flow
Your sunset policy should have three phases. Skip any of these and you're either too aggressive or too passive.
Phase 1: Frequency Reduction
When someone stops engaging, your first move isn't removal. It's backing off.
Drop them from your main sends. Create a segment called "Cooling Off" or something equally obvious. Send to this segment once a month instead of weekly.
Some people just needed breathing room. They'll come back. The ones who don't? They were already gone.
Phase 2: Re-engagement Campaign
After 90 to 120 days of silence, send a dedicated win-back campaign. Three to five emails over two weeks. Make the subject lines impossible to ignore:
- "We miss you (but we'll stop emailing if you want)"
- "Is this goodbye?"
- "Last chance to stay on the list"
Include a clear CTA. Click this link to stay subscribed. Don't click and we'll remove you. Binary choice.
The response rate will be depressing. Maybe 5 to 10 percent re-engage. That's fine. You're identifying the people worth keeping.
Phase 3: The Actual Sunset
Anyone who ignores your re-engagement sequence for another 30 to 60 days gets removed.
Not suppressed. Removed.
Yes, it feels brutal. Yes, your total subscriber count drops. Yes, your CMO will probably ask why the list shrank.
Show them the deliverability metrics. Engagement rates up. Spam complaints down. Inbox placement improving. That's the story that matters.
The Re-engagement Email That Actually Works
Most re-engagement emails are pathetic. "We haven't heard from you in a while!" Cool story. Neither has anyone else.
Here's what converts:
Subject: Your subscription is about to expire
Body: We noticed you haven't opened our emails in a while, and that's totally fine. Maybe you're busy. Maybe we got boring. Maybe you signed up for that discount code and never looked back.
Whatever the reason, we're cleaning up our list. If you want to keep getting our emails, click the button below. If not, do nothing and we'll remove you automatically in 7 days.
No hard feelings either way.
[Stay Subscribed] or [Unsubscribe Now]
That's it. Short. Direct. No guilt trip. No desperate discount offer. Just a clear choice.
The people who click are your real subscribers. Everyone else was already dead.
Common Sunset Mistakes
Mistake 1: Using opens as your only signal
Apple's Mail Privacy Protection pre-loads tracking pixels, which inflates your open rates. If you only measure opens, you'll think dead subscribers are alive.
Use clicks as your primary engagement signal. Or better, any meaningful action: site visits, purchases, profile updates.
Mistake 2: Sunsetting too fast
Cutting someone after 30 days of no engagement is insane. People go on vacation. They get busy. Life happens.
Give it at least 90 days of consistent silence before starting the sunset process.
Mistake 3: Never actually deleting anyone
Suppressing someone isn't sunsetting. You're just not emailing them while they continue dragging down your list quality metrics.
At some point, you have to delete. Hard delete. Gone forever. It's the only way to truly clean your data.
Mistake 4: No win-back attempt
Removing someone without giving them a chance to come back is wasteful. Always run a re-engagement sequence first. Some percentage will return.
FAQ
How often should I run sunset campaigns?
Continuously. Don't think of sunset as a quarterly project. Build it into your automation. Anyone who hits the inactivity threshold automatically enters the sunset flow.
Will sunsetting hurt my list growth?
Short term, yes. Your total subscriber count will drop. Long term, no. Your engagement rates improve, deliverability strengthens, and you can focus acquisition efforts on quality over quantity.
What about subscribers who never opened but also never unsubscribed?
They're dead weight. If someone has received 50 emails and opened zero, they're not engaged. Either they used a fake address, never check that inbox, or your emails go straight to spam. None of those scenarios are worth keeping.
Should I offer a discount in my re-engagement email?
I wouldn't. You're trying to identify who actually wants to hear from you, not bribe people into opening one more email before going dormant again. Save your discounts for engaged subscribers.
How do I explain the list shrinkage to leadership?
Frame it around quality metrics. "We removed 20,000 inactive subscribers and our deliverability improved by 15 points. We're now reaching more inboxes with fewer sends." Anyone who understands email marketing will get it immediately.
Start Your Sunset Today
Every day you wait, inactive subscribers drag your metrics lower. Gmail gets more suspicious. Your spam complaint rate creeps up. Inbox placement suffers.
Build your sunset segments now. Start with anyone who hasn't engaged in 90+ days. Run your re-engagement sequence. Remove the non-responders.
Your list gets smaller. Your results get bigger. That's the trade.