Personalized Future Mail Carrier Like Mommy T-Shirt. Postal worker T-Shirt - Navy Blue gift for a future mail carrier says when I grow up I wanna be a mail carrier like my Mommy. Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.