Ключевые слова: address, background, box, business, communication, concept, contact, container, contour, correspondence, delivery, design, email, envelope, flat, glowing, icon, illustration, inbox, internet, isolated, letter, letterbox, light, line, linear, lineart, mail, mailbox, mailing, marketing, message, neon, news, newsletter, open, outline, paper, pole, post, postage, postal, postbox, receive, send, service, sign, symbol,