Yes! Just you cannot claim anonymous unless you also sell and custody the domain (like njalla does - which technically means you don't own it) and make sure it is anon yourself, because if you don't then you'll get retards that paid their domain with credit card (or paid their protonmail address that way) and are surprised when they get picked up by popo, and blame you (like Proton gets blamed a lot.) Also because of all the crazy protocols you need to maintain DNS-side to actually get inbox delivery - as a user you'd want to outsource that too.

I think there's a nice niche here for someone that likes sats and understands how DMARC works though!