It's his problem, not mine. But where does that get me?

• I just read (and commented on) a great post by Peter Bregman on the limitations of trying to communicate in difficult interpersonal situations (my words). As I understand it, the gist of his post is that there are limits to what you can accomplish using communication. His example was that of a friend who disappointed him and then became angry when he called him on it in a reasonable manner. His (probably wise) conclusion is that it's sometimes better just to accept that the other person is the way he/she is, and that you won't always be able to change their behavior by talking to them. 
• As I mentioned in my comment, theoretically (and practically, for the most part), I agree. I definitely agree if I let my closet Buddhist alter-ego speak. :-) I can change myself but not others. But does that mean I have to accept every kind of behavior from someone else?
• Case in point is a family member of mine. I'll call him Fred. Our relationship (we've known each other since we were babies) has always been up and down. Even the fun moments were tinted with a kind of uneasiness, because the mood could change in a snap. I essentially moved to another state at 17 to go to college, and since that time we haven't had constant contact. We do have sporadic e-mail contact, though, because we're both involved in keeping an eye on a third family member. My experience with Fred is that he has a very short fuse. He takes offense easily. His response is to lash out verbally. (And I'm definitely doing the understatement thing here.) His words are chosen to be sarcastic and hurtful. I've even had him on an e-mail filter so I wouldn't be confronted with his negativity.
  (I should add that my relationship with his wife is fine.)
• A few years ago I tried the "modern" approach. I did not attack him for "being" a certain way; I told him how his abuse made me feel. His response was that he didn't give a s**t how I felt. About a year after that there was an almost identical situation. I told him again how I felt, said that I understood that he was having a rough time (he was, at that point), but that I would appreciate it if he would answer mails in a way that wouldn't discourage "people" (me) from having a conversation with him. Again, he didn't give a s**t.
• I can think of a lot of reasons he might be this way. He might be jealous of me. He might have a lot on his plate (he does). He might be afraid he's not going to measure up and is putting on his he-man suit. I have sympathy for all these things, if only because I've felt them myself. 
• But in this situation it just doesn't do enough for me to realize the problem is his, even if I'm convinced of it (which I am). I do have to deal with him, and I hate the way he treats me. How to deal with that gap? I'm following the comments on Bregman's article, but would love to hear from readers here. How do you deal with similar situations?