People aove him probably know about his issues.
I'm 13 years into my career and you'd be surprised about how higher ups will say "oh, that's John being John" if you bring it up in a politically correct manner. I've had supervisors say this along with peers.
Just do what you have to do to get your career on the right path. Don't worry about other peoples "problems". No one is perfect.
When people shit like this on you, talk to peers around you. You'd be surprised how unnecessary your e-mail was. t is just reiterating what everyone already knows.
A decent summary of my own though process.
