Sunset Policies for Dead Subscribers: When to Stop Emailing

A subscriber who has not opened, clicked, or bought in a year is not a lead, they are a deliverability risk. A sunset policy is the rule that stops mailing them before the inbox providers do it for you.

A sunset policy is a written rule for when a subscriber stops receiving regular campaigns: no opens, no clicks, and no purchases for a defined period, usually 180 days for clicks and 12 months for purchases. After that point the subscriber is suppressed from frequent campaigns and moved to a quarterly win-back flow, or removed entirely. The reason is deliverability. Inbox providers watch engagement across a sender's mail, and a list that keeps mailing people who never engage trains the provider to treat the sender's mail as unwanted. The deliverability cost lands on the engaged segment too, because the provider judges the sender, not the individual message. A sunset policy protects the list by shrinking it, and the revenue per send rises because the mail goes to people who read it.

The thresholds, and why they are what they are

The click threshold is 180 days, because a subscriber who has not clicked in six months has had dozens of chances to engage and taken none of them. The purchase threshold is 12 months, because a seasonal buyer can go a year between purchases without being dead. The combination matters: a subscriber who has not clicked in 180 days but bought 11 months ago is not dead, they are seasonal, and the sunset rule should check purchases before clicks. A subscriber who has not clicked in 180 days and has not bought in 12 months is dead by any measure, and the only question is whether to suppress or delete.

Suppress, do not delete, because deletion destroys the record and the reactivation option. A suppressed subscriber stays in the system, receives the quarterly win-back, and returns to the engaged segment the moment they click. A deleted subscriber is gone, and if they come back through a new signup, the store has lost the history that would have told it what they bought and when. Suppression is reversible. Deletion is not.

Related reading on this site: SegmentSage and Suppression Lists Are Segments Too, and They Rot on the Same Schedule cover the neighbouring problems in more depth.

The win-back flow before the sunset

Before a subscriber is sunset, they get a win-back flow: a short series, usually three messages over 30 days, that asks them to click to stay. The first message reminds them what they signed up for and what they have missed. The second offers a real incentive, not a generic discount, but something tied to what they bought before. The third is explicit: click here to keep receiving our mail, or we will stop sending it. The subscribers who click are re-engaged, and the ones who do not are suppressed with a clear conscience, because they were asked and they chose.

The win-back flow has to be honest about what happens next. A message that says we will miss you, click to stay, and then keeps mailing the subscriber who did not click is a lie, and the subscriber will discover it. A flow that actually suppresses non-responders is a flow the team can trust, and the suppression rate is the metric that proves it. If the win-back flow suppresses nobody, it is not a win-back flow, it is a re-engagement campaign with no teeth.

Measure the policy by revenue per send

The metric that justifies a sunset policy is revenue per send, not list size. List size falls the day the policy runs, and the team will panic, because list size is the number on the dashboard. Revenue per send rises, because the mail goes to people who open, click, and buy, and the deliverability improves because the inbox providers see engagement instead of indifference. The second metric is inbox placement, which should rise within a month of the first sunset run, and the third is the spam complaint rate, which should fall.

Run the sunset quarterly, not once. A list accumulates dead subscribers continuously, and a policy that runs once a year is a policy that is wrong for eleven months. The quarterly run is a maintenance task, like cleaning a list or updating a segment, and it belongs on the calendar with a named owner. The owner is the person who can see the engagement data and act on it, not the person who owns the brand. A sunset policy without an owner is a document, and a document does not suppress anyone.

Frequently asked questions

What is a sunset policy?

A written rule for when a subscriber stops receiving regular campaigns: no opens, no clicks, and no purchases for a defined period, usually 180 days for clicks and 12 months for purchases. After that point the subscriber is suppressed or moved to a quarterly win-back flow.

Why does mailing unengaged subscribers hurt deliverability?

Inbox providers watch engagement across a sender's mail, and a list that keeps mailing people who never engage trains the provider to treat the sender's mail as unwanted. The deliverability cost lands on the engaged segment too, because the provider judges the sender, not the message.

Should dead subscribers be deleted or suppressed?

Suppressed. Deletion destroys the record and the reactivation option. A suppressed subscriber stays in the system, receives the quarterly win-back, and returns to the engaged segment the moment they click.

How often should a sunset policy run?

Quarterly. A list accumulates dead subscribers continuously, and a policy that runs once a year is wrong for eleven months. The quarterly run is a maintenance task with a named owner who can see the engagement data and act on it.