Ability to set catch-all for a domain even if no mailboxes in that domain are set

[mario]

Use case:

I have domains xyz.com and xyz1.com. In xyz.com I set up a mailbox mario@xyz.com. In xyz1.com I want the catch-all mailbox to be mario@xyz.com but I can't set that.

[girish]

Indeed, currently catch-all has to have the feature to set mailboxes across domains (like aliases).