@kaia @hakui many domain providers offer something like that but it's actually configured on a mail server. your domain DNS settings tell everyone which other server is responsible to deliver mail for that domain, so if you run the server or a service offers it, they can just deliver all incoming mail to the same inbox. fastmail offers explicit catch-all, proton does not i think, but you can achieve it by having an in-between mail relay that is run by your domain registrar (that only forwards mail to your actual address), many offer that service.