Inactive subscribers: how to define them, and when to stop mailing them

Deciding what inactive means in your account

Nobody agrees on this, and that's the problem. Somebody picked a window years ago because it was a default. Finance wants every address kept. Settle it once, write it down, and use it everywhere.

Base it on what people do. Clicks, site visits and orders are real signals. Opens aren't any more, because Apple's Mail Privacy Protection loads email images in the background, so an Apple Mail user can look engaged forever without reading a word.

Then set the window past your natural buying cycle. A coffee subscriber who goes quiet for a month is drifting. A sofa buyer who goes quiet for a year might be perfectly happy.

What a quiet subscriber costs you

• Every send to them drags down the engagement mailbox providers judge you on
• Some long-dead addresses end up as spam traps
• In Klaviyo, they count towards the profiles you pay for until they're suppressed

That third one tends to end the argument with finance. Klaviyo's help centre is clear that suppressed profiles don't count towards your bill, so the cleanup shows up on the invoice before it shows up in deliverability.

Building an inactive subscriber segment in Klaviyo

• Subscribed to email, and not already suppressed
• No email clicked inside your window
• No order placed inside your window
• No visit to the site inside your window
• Joined before the window started, so new subscribers aren't swept in

Then put it to work two ways. Leave it out of every campaign by default, and feed it to a sunset flow that asks one plain question before it suppresses anyone. Suppressed, not deleted, so their order history stays and they can sign up again whenever they like.