Sunset policies: when to stop emailing inactive subscribers

A sunset policy is a rule for what happens to subscribers who stop engaging. Instead of mailing them forever, you try to win them back, and if that fails, you stop.

Why bother

Mailbox providers pay attention to whether people engage with your mail. If a large part of your list never opens, those unread messages look like unwanted mail, and reputation drifts down. Old, unopened addresses are also where recycled spam traps live (more on traps).

Cutting dormant subscribers will shrink your list. It will usually improve your open rate, your reputation and your reporting, and it lowers what you pay your email platform.

Step 1: define "inactive"

Choose a window that fits how often you send:

• a weekly newsletter: no opens or clicks for 3 to 6 months might be dormant
• a monthly one: 6 to 12 months
• a retailer: consider purchase history as well as opens

Be aware that some mail apps preload images or block tracking, which can make opens unreliable. Clicks, purchases and logins are firmer evidence.

Step 2: segment them

Create a segment of subscribers who haven't engaged within your window but who joined before it, so you don't flag brand-new subscribers.

Step 3: run a win-back sequence

Send two or three messages over a couple of weeks:

1. A friendly "are we still right for you?" with a compelling reason to click.
2. A reminder of what they get, or a one-click choice about frequency.
3. A last note: "we'll stop emailing you unless you click".

Make the click effortless, and make leaving easy too.

Step 4: remove the silent ones

Anyone who doesn't respond is moved to a suppressed state. Don't delete their record if you need to remember that they were removed, otherwise a later import might put them straight back.

Step 5: verify what remains

A sunset policy deals with people who don't engage. It doesn't tell you which of the others are bad addresses. Run verification on the active list too, so dead mailboxes don't hide behind low engagement.

Exceptions

Transactional email, such as receipts and security notices, is separate. Customers still need those, so keep them out of your sunset logic.

Make it automatic

Set the policy up as an automation in your email platform and review the numbers each quarter. The first run usually removes the most, and later runs are small. Then check how your bounce rate changes.