Feature request: Reject action for Email routing and 1:1 domain catch-all address rewrites

Hello all and thank you for all your great work!

I would like to request the possibility to add custom addresses with the action reject to actively reject any incoming message to that address with “SMTP 553 No such user” or similar. This would be useful to me when using catch-all and have identified that one or more addresses are targets of spam. I believe it is better to reject e-mails that should be rejected, rather than just dropping them silently and letting the sender think it was accepted for delivery and making them continue to generate unwanted spam traffic to those addresses.

I would also like to see the ability to verify a target domain for catch-all address translation/rewrite so [email protected] would go to [email protected] (preferably with the option of doing things like [email protected] to [email protected]).

Cloudflare already seem to ask the receiving MX of the external domain if the address is valid in order to reject it directly, so that would enable me to reject addresses at the receiving mail host, at least for me who has a mail host that happens to have the ability to reject specific addresses while using catch-all.

I like to hear your thoughts on this. Thank you.