Thank you, Pinkdog. That is helpful advice.
I am not speaking with him when he drinks, only sober. And if he gets angry or insulting, I do shut the door and refuse to engage. But I do send him things during the sober hours to try to encourage him. Maybe I should stop that and just wait until he contacts me first--always. I just want him to know I care and he's not alone, but maybe I should let him lead all of the interaction. And of course, only speak to him when he's kind.