Exceptions to catch-all

I'm migrating to Zoho mail.

I have used catch-all extensively, usually I give a unique address to each wesite I sign up for. Then I can block that recipient address if they sell my address to spammers. It's worked well with my last vendor.

For example, my main catch-all address is example@example.com. If someone fat-fingers and sends exMAple@example.com, it still gets to me. But if they send to AddressCreatedJustForSomeSpammerCompany@example.com or AnotherAddressCreatedJustForSomeSpammerCompany@example.com, these messages are rejected or discarded.

Now at Zoho I need to add a few exceptions so that mail sent to certain addresses is discarded.

How do I do that please?

I suppose one way is to create full users for these addresses but I don't want the messages to fill up the quotas. I just want messages to be rejected.

How?