book buyer buyers check checkbox customers discount free group link list mailing newsletter paid payment refunded reversed send specifically update whose

How can I send a newsletter ONLY to customers who actually PAID for my book? I want to send them a discount for my new book. But I don't want the people I sent my book to free to have it.

The update/newsletter goes to the buyer group only. So, if you sent someone a free link but did not specifically check "add to mailing list" checkbox, then they will not be send the newsletter.

Also, buyers whose payment are refunded or reversed are taken off the mailing list as well.