Jail mail

ughhhhh so I was supposed to get a letter like 2 weeks ago it got sent back to him because he said he didn't put a stamp so he said he sent one again this Sunday or I think Saturday he said I should get it today and I didn't get it again!!!!!! it's just been making me so upset I currently just moved in with his mother when he got incarcerated so my last name isn't on the mail box could that he a reason also ?