Protonmain – secure email from scientists and engineers of CERN and MIT

I would like to move to a new mail provider, but to be honest: That "enterprise/professional" support is pretty much a joke:

If you want to use a custom domain because you not only have an own domain, but want to add let's say 5 co-workers to use their service, you have to share ONE (!) Login with all co-workers, because you can not create sub-accounts nor share one custom domain over several accounts.

See: https://protonmail.com/support/knowledge-base/custom-domains...

That was the point, where I was out of the game ...