I believe it is based on the contact data of the delivery, not the start
date of the campaign. Those are two different objects. Also, the
validity is only good for emails that still in re-try status. So if your
email with a 2-day coupon is delivered on day 0, on day 4 it will still
be in the person inbox because the delivery status is = finished.
Nothing is erasing the email once it is in your customer's inbox. If on
Day 0 the status of a recipient's email is pending or re-try, and the
status re...