Giving up hopes staying sarcastic

I have a distant friend, distant, meaning that he does not live in the same country as I am. He has a sort of alcoholic and smoking related problem which has lead to a heart disease, which will kill him anyday. He knows why he has this heart disease and he knows that quit smoking and drinking will make him escape a certain death. But he doesn't want to. We can go on analyzing why he doesn't, but thats disrespectful. I'm rather wondering why I'm trying to convince him to stop when he doesn't want to, and then in the end, living in all this misery, I fail to do anything else but give up. So now, I'm being sarcastic instead. Going sort of: "Hi!, (if you're still alive)" in my e-mails, which he by the way, only answers occasionally since he goes through periods of depression.

Today I wrote him a letter. I will send it merely by playing detective. If I get it back by the post office, I presume that he is dead.