Wow, I did not expect that from Proton, thanks for the links and the summary - very useful!

If a provider can access customer data, then unfortunately in the world as it is they will be forced to hand over some of it sooner or later. 

 sure, we offer setups of this including the domain, first month of the VPS, and a full year of support:

https://simplifiedprivacy.com/email-cloud-combo/index.html

Unlike the other softwares out there, you get more than one service on the VPS, 

and at the end, we hand over all passwords