Are we to believe...
...that Klinger NEVER wrote home to his Mother? I would think if he had, the envelope would have had a Korean post mark of some kind on it. He claims she didn't know he was in Korea during the Season 7 finale "The Party", but as it turns out, she did know he was there after all. I just find it strange that in all the time Klinger was there at the 4077th, he never once wrote to her and those envelopes did not have Korean post marks or any kind of unusual markings on them.