What is “consent aging”?

You got a subscriber two years ago. They opened your welcome email, maybe clicked once, and then went quiet. You've been sending ever since. Is that consent still valid? That's the question consent aging asks.

Consent aging is the idea that permission to email someone loses its relevance over time. Someone who signed up three years ago and hasn't opened anything in eighteen months probably doesn't remember subscribing. Their interests may have changed. The relationship has gone cold. Legally and practically, that old consent starts to look pretty thin.

No regulation sets a hard expiration date on consent (GDPR doesn't, CAN-SPAM doesn't), but that doesn't mean old consent is forever safe to act on. Regulators in GDPR territories have pushed back on very old or stale consent, arguing it no longer reflects genuine, current intent. And beyond the legal angle, stale consent is a deliverability problem. Subscribers who don't remember you are far more likely to hit the spam button, which damages your sender reputation with every mailbox provider.

The practical fix is a re-permission campaign. If a subscriber hasn't engaged in a set window (many senders use 12 to 18 months as their threshold), you send them a simple message asking if they'd like to keep hearing from you. If they confirm, great. If they don't respond, you move them off your active list. It feels counterintuitive to remove people who technically never unsubscribed, but it's the right call for your list quality and your reputation.

The re-permission email doesn't have to be heavy-handed. Something like "We haven't seen you in a while. Want to stay subscribed?" with a clear yes button is plenty. Keep the unsubscribe path just as obvious as the yes path. (Hiding the exit is never a good idea, for trust or for compliance.)

If you're working through an older imported list and want to know how to verify that consent holds up before you even start sending, the next question covers exactly that.