What’s the acceptable reactivation window for inactives?

You've got subscribers who haven't opened anything in months. Maybe a year. At what point do you stop hoping and start suppressing? That's the reactivation window question, and the honest answer is: it depends on how often you send.

The general rule of thumb is 3 to 6 months of inactivity for frequent senders (daily or a few times a week) and 6 to 12 months for monthly senders. If you send once a month and someone hasn't engaged in six months, that's only six emails. That's a bit early to give up on them. But if you send daily and someone hasn't clicked or opened in 90 days, that's roughly 90 ignored emails. That's a signal worth acting on.

Before you suppress anyone, run a re-engagement campaign. A short sequence (2 to 3 emails maximum) with clear "we've missed you" messaging and something worth clicking. If they don't respond, that's your answer. Suppress them, don't delete them forever, but stop sending regular campaigns to that segment.

One thing the 6-to-12-month window doesn't account for is why someone went quiet. There's a real difference between someone who signed up and never opened a single email versus someone who was active for two years and gradually faded. The long-time fader is worth a more personal re-engagement attempt. The person who never opened anything? They probably shouldn't have stayed on your list this long in the first place.

Also worth flagging: if you're sending to EU-based subscribers, GDPR has something to say about this. Consent doesn't stay fresh forever. If your legal basis for emailing someone was their original opt-in and they haven't engaged in 12+ months, you may not have a defensible basis for continuing to email them at all. A re-permission campaign (where they actively re-confirm they want to hear from you) is the cleaner path than just re-engaging through regular sends. (That's a legal-ish consideration, so if you're unsure, it's worth a quick check with whoever handles compliance on your side.)

And the practical breakdown looks something like this:

• Daily senders: flag inactives at 60-90 days, run re-engagement at 90 days, suppress at 120
• Weekly senders: flag at 3 months, re-engage at 4-5 months, suppress at 6
• Monthly senders: flag at 6 months, re-engage at 8-9 months, suppress at 12

These aren't hard rules. They're starting points. Your list's behavior, your industry, and your content type will all shift these numbers slightly. The key is having a policy at all, and actually following through on it. Most deliverability problems that come from inactive subscribers happen because someone kept delaying the decision to suppress.

If you're not sure what counts as "engagement" for your purposes, opens are the weakest signal (Apple Mail Privacy Protection has made open tracking unreliable). Clicks are much stronger. Purchases, replies, or any kind of conversion are the strongest. Build your inactivity definition around clicks if you can.

Not sure where to start with your specific list? Our SOS hotline is free and we're happy to help you think through a suppression strategy that fits your send frequency.