I'm right there with you. It's a criminally underrated film and one of the best post-apocalyptic movies ever.
I fully admit that it has some problems. A couple of scenes are a little schmaltzy, a couple of lines come off as wooden, and it could have used an edit to smooth up the pacing a tad. But other than that? It has an interesting story, awesome set and costume design, fantastic cinematography, an awesome bad guy, and one of my favorite scores of all time. There's a lot to like about The Postman, especially if you're a fan of the post apocalyptic genre.
****SPOILERS POSSIBLE**** I read the book. The book started off really good UNTIL the POSTMAN encountered some old dude and some kind of super strength humans or whatever started in and the old dude was the hero. The way KC presented the movie was ten times better. I like the plot twist concerning the figure 8 and when PM and Bethlehem have their showdown, PM rips his shirt sleeve, screaming, "I evoke law 7 of the laws of 8---any member may challenge for leadership of the clan". This might not be word for word, but basically that's what was said. And then he rides around to show Bethlehem's men his arm. The team he brought to back him up is shocked. I love that part. Another part I think is shear genius is when the lion in the forest has killed one of Gen. B's guys and they make KC go after it. When he gets the guy and is carrying his bones back across that rickety bridge over the river and purposely crashes through the rotting wood, plunges into the river and swims for his life is just exhiliration. The music on the Postman is really good. I love this movie. Don't diss till you see it.