I would suggest not brining up the mail issue again. You called an apologized...just use what you learned the next time (if he does) make the comment about you opening "his" mail.
Quote: Yesterday my H and sons were putting up treestands all day and I felt left out, I guess I'm realizing I'd rather be with them than sitting here by myself. I also remember at one point feeling like my mom, my dad and bros used to all go hunting and my mom would sit at home waiting for them to come back, make the meal, serve them, etc. I don't want to be like that I'd rather be a part of the action rather than the one sitting at home.
Is there some reason why you can't go outside and help your sons and their father?