Limit multi-class campaign discount codes to one use per email

We would like the ability to restrict a multi-class campaign discount code so that each customer can only use it once per email address. This would help ensure that one-time offers, such as welcome discounts, are not repeatedly used by the same customer, maintaining the exclusivity and intended purpose of the promotion.

Currently, Discounty does not provide a direct way to enforce this type of limit for multi-class campaigns. Adding this functionality would help merchants protect their promotional campaigns from abuse, ensure fair usage, and encourage new purchases from unique customers.

If you think this would help keep your campaigns fair and effective, please upvote this request!