No you can't be ee2e is the receiving end is also not ee2e... that is normal isn't it??
If I spoke Dutch and you spoke French... we won't be able to understand each other... That seems normal to me...
Yes you need trust.. and yes I don't work for Tutanota. So I don't know entirely if they don't leak.
But hey I don't work at my bank. And I trust them to get my money safely across...