Email Sunset Policies: When and How to Remove Inactive Subscribers

Why Sunset Policies Exist

Every inactive subscriber on your list is a small weight dragging down your sender reputation. Gmail, Outlook, and Yahoo track how recipients interact with your email. When a large percentage of your list ignores every send, mailbox providers conclude your mail isn't wanted.

The math is simple. If you send to 100,000 subscribers and 40,000 never open, your engagement rate looks terrible to mailbox providers. Remove those 40,000, and the same engagement from 60,000 subscribers produces a much stronger signal.

Sunset policies formalize this removal process so it happens consistently rather than when someone remembers to clean the list.

Building Your Sunset Policy

Phase 1: Identify Inactivity (Day 0-90)

Define "inactive" based on your sending frequency:

Sending Frequency	Inactivity Threshold
Daily	30 days no opens/clicks
2-3x per week	60 days no opens/clicks
Weekly	90 days no opens/clicks
Bi-weekly/Monthly	120 days no opens/clicks

The principle: if a subscriber has received 10+ emails without engaging, they're inactive. Adjust the day count so it corresponds to roughly 10-15 sends.

Important: Use clicks as the primary signal, not opens. Apple Mail Privacy Protection inflates open rates. A subscriber who "opens" every email via privacy proxy but never clicks is not engaged.

Phase 2: Re-engagement Campaign (Day 91-120)

Before removing anyone, give them a chance to re-engage. See our full re-engagement campaign guide. A 3-email re-engagement sequence:

Email 1 (Day 91): "We miss you" / "Still interested?"

• Simple, direct subject line
• Remind them what they subscribed for
• Clear CTA to click and confirm interest

Email 2 (Day 98): "Last chance" / Offer an incentive

• Different angle than email 1
• Consider a discount, free resource, or exclusive content
• Make clicking easy and low-commitment

Email 3 (Day 105): "We're removing you"

• Final notice — honest and direct
• "Click here to stay subscribed, or we'll stop emailing you in 7 days"
• This subject line typically gets the highest open rate in the sequence

Practitioner note: The "we're removing you" email consistently outperforms the other re-engagement emails. People respond to loss aversion. I've seen 8-15% of seemingly inactive subscribers re-engage on this final email alone.

Phase 3: Suppression (Day 120+)

Anyone who didn't engage during re-engagement gets suppressed from all sending. Don't delete them yet — suppress them. The difference matters:

• Suppressed — still in your database, excluded from sends, can re-engage via other channels (website visit, purchase)
• Deleted — gone from your system entirely

Keep suppressed contacts for 60 more days. If they interact with your brand through any other channel during that period, re-activate them.

Phase 4: Removal (Day 180)

After 180 days of total inactivity (90 pre-sunset + 30 re-engagement + 60 suppression), permanently remove the contact. At this point, the address may have gone bad entirely, and keeping it risks spam trap hits.

Implementation by ESP

Klaviyo

Use Klaviyo's built-in engagement segments: "Has not opened or clicked email in the last 90 days." Create a sunset flow triggered by segment entry. Use Klaviyo's suppression lists for phase 3.

ActiveCampaign

Build an automation triggered by "Contact has not opened email in 90 days" condition. Use contact scoring to track engagement. Move non-responders to a "sunset" list that's excluded from all other automations.

Mailchimp

Use Mailchimp's engagement-based segments (inactive subscribers who haven't opened in X campaigns). Create a re-engagement automation. Archive non-responders.

HubSpot

Use HubSpot's list filters to identify contacts with no email engagement in 90 days. Build a workflow for the re-engagement sequence. Use suppression lists for non-responders.

Practitioner note: Most ESPs charge based on contact count. Sunsetting inactive subscribers doesn't just improve deliverability — it reduces your ESP bill. I've seen clients save $200-500/month just by removing contacts they were paying to not reach.

Sunset Policy Exceptions

Not every contact should follow the same sunset timeline:

Recent purchasers. A customer who bought last week but hasn't opened emails in 90 days might just have email fatigue. Extend the sunset window for recent buyers to 180 days.

High-value contacts. Enterprise leads, large accounts, or strategic contacts might warrant manual review before sunsetting rather than automatic removal.

Seasonal buyers. Some audiences are naturally seasonal (holiday shoppers, tax season services). Adjust sunset timelines to account for predictable inactive periods.

Transactional recipients. Never sunset customers who receive transactional email (order confirmations, account updates). Transactional email is expected regardless of marketing engagement.

Measuring Sunset Policy Impact

Track these metrics before and after implementing sunsetting:

• Open rate — should increase (denominator shrinks)
• Click rate — should increase
• Spam complaint rate — should decrease
• Gmail domain reputation (via Postmaster Tools) — should improve
• Bounce rate — should decrease as stale addresses are removed
• Revenue per email — should increase (fewer emails generating same revenue)

The deliverability improvement typically appears within 2-4 weeks of implementing a sunset policy on a list that's never been cleaned.

Common Mistakes

No re-engagement before removal. Always give people a chance to re-engage. Removing without notice loses recoverable subscribers.

Using opens as the only signal. Apple Mail Privacy Protection makes opens unreliable. Use clicks as the primary engagement indicator.

Sunsetting too slowly. A 365-day sunset window is too long. You're damaging your reputation for a full year before taking action. 90-180 days is the right range.

Sunsetting but not preventing. If you sunset 30,000 contacts but keep acquiring unengaged subscribers through bad list practices, you're treating the symptom, not the cause.

The Bottom Line

A sunset policy is non-negotiable for any serious email program. It protects your sender reputation, reduces your ESP costs, and focuses your sending on the subscribers who actually want your content. The initial list size reduction feels painful, but the deliverability improvement is immediate and significant.

If you need help designing a sunset policy for your specific audience and sending patterns, schedule a consultation — I'll build a sunset framework that maximizes re-engagement recovery while protecting your reputation.

Sources

• Gmail: Bulk Sender Requirements
• Validity: Re-engagement Campaign Best Practices
• M3AAWG: List Hygiene Best Practices
• Klaviyo: Sunset Flow Documentation

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v1.0 · March 2026