MTA Mode - Block a domain

Hello Guys,

I think I am going crazy...

I would like to block the domain "" from the Email Protection. I know it is possible in "Legacy mode" :

But in that case the customer has setup his Email protection with MTA Mode. I can't find a way to do this simple task in this mode...

In the "General Settings" tab, there is a "Blocked Email Addresses" list, but here you can only add complete email address and you can't add domains.

Please tell me there is a way in the MTA mode to block a domain.