Email Sunset Policy: When to Stop Emailing Inactive Subscribers

An email sunset policy is a written rule that says when you stop sending marketing email to subscribers who no longer engage. It defines what “inactive” means for your list, what happens at each stage (send less, try to re-engage, then stop), and which contacts are exempt. Having it in writing turns list cleanup from an occasional panic into an automatic process, and it keeps the inactive share of your list from dragging down your inbox placement.

This post walks through how to write one, with a template, sample thresholds, and the automation logic to enforce it.

Why you need an email sunset policy

Every list accumulates people who signed up, stayed for a while, and then stopped paying attention. Without a rule for them, they stay on the list forever, because no one wants to be the person who deleted ten thousand “subscribers.”

The cost of keeping them:

• Weaker engagement signals. Mailbox providers watch how recipients interact with your mail. Google’s sender guidelines explicitly suggest that senders consider unsubscribing recipients who don’t open or read their messages.
• More complaints. People who have forgotten about you are the most likely to hit “report spam.” Gmail asks senders to keep spam rates below 0.10% and to avoid ever reaching 0.30%.
• Dead and repurposed addresses. Yahoo says a mailbox that hasn’t been accessed for 12 months becomes inactive and stops receiving new email. Long-abandoned addresses can also end up as recycled spam traps; see spam traps: the two kinds and how they got on your list.
• Wasted spend. Most email platforms price by contact count or send volume.

A sunset policy is how you decide, in advance and consistently, when those costs outweigh the chance that someone comes back.

Sunset policy vs re-engagement campaign vs suppression list

These three are related but not the same:

Tool	What it is	Role in the process
Sunset policy	The rule: who counts as inactive, and what happens at each stage	Decides
Re-engagement campaign	The messages sent to inactive people before removal	Asks
Suppression list	The list of addresses you no longer mail	Enforces

The policy is the piece most teams skip. Without it, re-engagement campaigns happen once, and suppression only catches bounces and unsubscribes.

Step 1: Define engagement for your business

Decide which actions reset someone’s “last active” date. The stronger the signal, the more you should trust it.

Strong signals

• Clicked a link in an email
• Replied to an email
• Made a purchase
• Logged in to your product
• Updated preferences

Weak signals

• Opened an email

Opens are weak because Apple Mail Privacy Protection downloads remote content in the background by default, whether or not the person reads the message. If opens count as engagement in your policy, privacy-protected readers who never look at your mail will never be sunset. A common compromise: count clicks and on-site activity as engagement, and treat opens alone as “unknown.”

Step 2: Set the inactivity thresholds

Pick thresholds that fit your sending frequency. A useful rule of thumb is to allow enough sends that someone with normal habits would have clicked at least once. The table below is a starting point, not a standard; adjust it after you look at your own data.

Your send frequency	Reduce frequency after	Start re-engagement after	Sunset (stop marketing) after
Daily	30 days no click	60 days	90 days
Weekly	90 days	150 days	180 days
Monthly	6 months	9 months	12 months
Quarterly	9 months	12 months	18 months

To check your thresholds against real behavior, look at how long it usually takes active subscribers to click again. Export each subscriber’s click dates and compute the gap between consecutive clicks. If most of your engaged readers click within 60 days of their previous click, a 180-day sunset threshold gives them plenty of room.

One more anchor point: M3AAWG’s Sender Best Common Practices describes a “dirty mailing list” as including addresses that haven’t been mailed in a year or more. If your policy would let someone go a year or longer without any real engagement and still receive mail, it’s probably too loose.

Step 3: Define the stages

A good sunset policy has stages rather than one hard cutoff. Here’s a four-stage model:

1. Active. Engaged within your threshold. Full sending.
2. Cooling. No engagement for a while. Reduce frequency: send only your best content, such as a monthly digest instead of weekly emails.
3. Re-engagement. Past your re-engagement threshold. Send a short re-engagement sequence asking them to click to stay.
4. Sunset. No response to re-engagement. Stop marketing email and add to your suppression list with reason “sunset.”

The cooling stage matters. Reducing frequency lowers the volume of unwanted mail while still giving people a chance to come back on their own. Segmenting your list by engagement covers how to set up those tiers.

Step 4: Decide on exceptions

Some contacts shouldn’t be sunset on email activity alone. Common exceptions:

• Recent customers. Someone who bought last month but never clicks your newsletter is still a customer. You might keep them on order-related and account mail while sunsetting them from promotions.
• Active product users. A SaaS user who logs in daily doesn’t need to click newsletters to count as engaged.
• Transactional mail. Receipts, password resets, security alerts, and account notices are not marketing and shouldn’t be affected by a marketing sunset policy.
• New subscribers. Anyone who joined after your threshold period started can’t be inactive yet. Base inactivity on the later of their signup date or last engagement.

Write the exceptions down. Unwritten exceptions become “keep everyone, just in case.”

Step 5: Automate the email sunset policy

A sunset policy only works if it runs without someone remembering to do it. Most email platforms can do this with segments and automations:

1. Create a segment for each stage using your engagement definition, for example “last click older than 150 days AND last purchase older than 150 days AND signup older than 150 days.”
2. Build an automation that enters people into the re-engagement sequence when they join that segment.
3. Add an exit rule: anyone who clicks during the sequence leaves the flow and returns to Active.
4. At the end of the flow, non-responders are tagged “sunset” and unsubscribed or suppressed from marketing.

If your platform can’t do this, a monthly spreadsheet export works. With last click in column B, last purchase in column C, and signup date in column D:

=LET(last, MAX(B2, C2, D2), days, TODAY() - last,
  IF(days > 180, "sunset",
  IF(days > 150, "re-engage",
  IF(days > 90, "cooling", "active"))))

LET works in current Google Sheets and Excel for Microsoft 365. In older Excel, replace each days with TODAY()-MAX(B2,C2,D2).

Step 6: Write the policy down

A one-page document is enough. Here’s a template you can adapt:

Email Sunset Policy (Marketing Email)

Scope: All marketing and newsletter email. Transactional and account email is out of scope.

Engagement means: a click, reply, purchase, or product login. Opens alone do not count.

Stages:

• No engagement for 90 days: reduce to monthly digest only.
• No engagement for 150 days: enter a 3-email re-engagement sequence over 14 days.
• No response to the sequence: unsubscribe from marketing; add to suppression with reason “sunset.”

Exceptions: customers with a purchase in the last 180 days stay on promotional mail at reduced frequency.

Re-subscribing: a sunset contact who signs up again through a form and confirms is treated as a new subscriber.

Owner and review: [name], reviewed every 6 months.

Having it written down also helps if your sending provider ever asks how you manage your list. AWS, for example, asks accounts under review to describe their bounce and complaint handling processes and the changes they’ve made, per its reputation guidance.

What to do with sunset contacts

Sunset doesn’t have to mean deleted. Options:

• Suppress from marketing, keep the record. Most common. Their history stays for analytics and they’re blocked from re-import.
• Use other channels. If they’re a customer, they may still respond to in-app messages or ads to a hashed audience, depending on your consent and the platform’s rules.
• Allow re-entry through confirmed signup only. If they come back to your site and subscribe again, require a confirmation click so you know it’s really them. See double opt-in vs single opt-in.

What you shouldn’t do is quietly add sunset contacts back to a big campaign because sales were slow that month. That’s how a clean list gets dirty again in a single send. If you ever do need to re-mail an old segment, check it first; our free email verifier will flag dead domains, missing MX records, disposable domains, and typos, though it doesn’t connect to the mailbox itself.

FAQ

What is an email sunset policy?

It’s a documented rule for when you stop sending marketing email to subscribers who no longer engage. It usually includes an inactivity definition, a reduced-frequency stage, a re-engagement attempt, and final removal from marketing sends.

How long should I wait before sunsetting a subscriber?

It depends on how often you email. Weekly senders often sunset after around six months without a click; monthly senders might wait a year. Check your own data on how long engaged subscribers typically go between clicks and set the threshold comfortably beyond that.

Does a sunset policy apply to transactional emails?

No. Receipts, password resets, and account notices should keep going to anyone who needs them. A sunset policy covers marketing and newsletter mail only.

Will sunsetting subscribers shrink my list too much?

Your list count will drop, but those contacts weren’t reading anyway. Your engagement rates and deliverability usually improve, which means more of your mail reaches the people who do read it.