Well, here are my thoughts for what they are worth. I saw this movie differently than most of you. I saw a man who was so in love with his friend that he could hardly stand it when they were apart.
And then I saw a man who was a homophobe. A man that met the first one while working together and over a short time became best friends. Best friends so deeply that he allowed himself to become intimate with him, as long as they were out of sight of others and in the middle of nowhere. This was Ennis' only friend. His love and affection for Jack was so deep that even he didn't realize that he was in love with Jack, or, wouldn't allow himself to think it. That is, until he found the shirts. He then realized how much Jack was in love with him and how much he was in love with Jack. And for the first time says, "I love you." [Kleenex please, anyone?]
When Ennis was divorced we saw a macho man, a man who was ready to fight at the drop of a hat, stand in an open court room and weep. I believe he was devastated by the divorce. He needed to tell someone. He was all alone. He was the bad guy in everyone's eyes. Why not tell his best friend, the one person he had genuine love and admiration for? So he sends a postcard telling Jack he was divorced. We don't know what the card said but we do know Ennis was shocked to see Jack standing in his yard one day. So the card didn't call out for help in dealing with the situation. Jack's happy demeanour tells us it wasn't that. He didn't come to comfort Ennis. I believe it was just Ennis needing to tell someone and having nobody but Jack to tell. And in Ennis form, he said very little, he wrote it on a post card after all. But, we do know, whatever it said it renewed Jack's hopes for their future. But then, Jack is the dreamer. He probably read a four page letter of love and finally living together; and all on a little post card. God, how Jack did love Ennis. And Ennis, too ignorant or to afraid to understand or admit how much he was loved...until it was too late to do anything about it.
My 2¢.