The New York Post‘s real estate section counsels apartment dwellers on their doorjamb rights. If the little old lady in 2A is allowed one of those incredibly tacky faux flower wreaths, then you can attach a mezzuzah to the doorposts of your house. However, freedom being what it is, a landlord can’t discriminate against religious objects even if your neighbors are Satan-worshipping freaks who decorate the hallway with cow’s liver.