Can Gross be configured to give perpetual 4xy errors instead of 5xy?
Yes, if the block threshold is met, it means that the bloom filters won’t be updated. If you change the sjsms_reponse_block to a 4xy error, it means there will be perpetual temp blocks. Returning 5xy is more polite in some ways, because senders get notified immediately of a delivery failure. With 4xy it takes at least a couple of hours (4 is typical) for sender to get the notification. However, it’s possible for the owner of a legitimate server that was falsely blacklisted to request delisting and still have those deferred messages deliver. You might get fewer complaints from users, or the complaints might be different.
