Yes; he used to drive to work drunk and pass out in the car until he became sober and then come home late pretending to be working late and being very tired. (my sis-in-law and parents all believed this or wanted to believe it)
How should I break this to the immeadite family, without letting them know that I accessed his private emails???
I don't think his privacy is an issue here. He needs intervention from you and your family immediately so that he can get better and don't put himself or anyone else in harm's way.
This is not going to be easy for you, your family or him. He will deny and resist everything that you and your family will try to do for him initially but he's not in the right state of mind. I also believe he needs professional help with rehab and a psycologist to see why he's drinking int he first place.
Good luck with everything and stay strong.