Write to one reason they left
Price, timing, trust, or confusion. Pick one per email. "We miss you" is not a reason. "You left before you saw the setup checklist" is.
Give something useful even if they never buy
A short tip from the same topic as the offer keeps the list warm. The second-chance pack is about revenue; the ethical version still teaches. That is how people stay subscribed.
Make restarting easy
One link back to the same offer. Same price story. If you changed the offer, say so in the first line. Confusion is how second chances fail.