Ключевые слова: address, advertising, background, box, business, card, communication, concept, container, correspondence, day, delivery, design, envelope, free, hand, icon, information, isolated, label, letter, letterbox, mail, mailbox, mailing, marketing, message, metal, open, paper, parcel, people, person, post, postage, postal, postbox, public, putting, recipient, red, remove, send, service, sign, symbol, unread, valentine, white,