Nice to finally see this...
"The encrypted email provider announced Thursday it will allow its users to access the site through the Tor anonymity service.
The aim is to allow its more than 2 million users access the provider by taking "active measures to defend against state-sponsored censorship," such as government-mandated blocks at the internet provider level.
Users of the Tor Browser can now access the site at https://protonirockerxow.onion. "