CatchAll yet Block some 'to' addresses

[c00]

My setup is possibly a bit unusual, so let me give you some background.

The way I deal with spam, is I have a (sub)domain with a catchall address. Every site/service I have to sign up for, I put down a different email address. It all ends up in the Catchall box anyway. This way I can monitor who sends me what, and which companies are abit too flexible with their(or my) privacy concerns. As soon as one of the addresses gets spam, I block that specific 'to' address, and no more spam.
I used to create an alias for every site/service, but decided this is too much work, hence the catchall address.

Now, I used to host my mail on a cPanel controlled server, which has the ability to create a 'forwarder' that rejects messages based on the 'to'-address. Is this possible with Zimbra? And how?

I found a lot on blocking senders, but that doesn't really work well for me. I want to make the address they're sending to disappear.

[phoenix]

The simple answer to your question is, it's not possible to have a 'catchall' address and block some email - it's illogical to accept all mail then reject certain email. I've never really understood the need to sign-up for each service with a different email address. If you get spam from a particular site then just mark it as spam and it will get stopped after a couple of times doing that. You can also add the sender to your own block list.

[c00]

I appreciate your opinion, but it doesn't really help my situation.
My reason for doing this, is because spammers can easily email you from different servers and/or email addresses. So as soon as my address gets known in those circles, it's an endless ocean of spam from there on until forever. Simply removing the alias, solves everything.