I'd like to implement per-recipient limits for incoming mail to our Postfix MX servers, but I don't know what to use to achieve that. Postfix docs and Google searches will only give me config recipes to set up (global) incoming concurrency or throttle mails coming out of Postfix.
As an example, if a given recipient receives more than 1000 mails in the last 60 seconds, we'll block it with temporary error codes for the next 60 minutes.
So far I hadn't found anything and missing other options I'd probably try to hack together something that scans log files and edits Postfix
check_recipient_access access list.
[if someone is going to ask the reason, it is spam mail coming from usually legit servers (those with good IP reputation, good PTR records, not present in any RBL, etc) to a given single recipient address. We got flooded a couple times and our amavis servers took a long time to empty the queue, we'd like to prevent that flooding]