One of my friends was in his holiday in Zanzibar. And he was so kind to make photos with the post office and mail boxes located in Shangani old town area. That part was designated in 2000 as UNESCO .
More info about Tanzania Post here: https://www.posta.co.tz/
Lebanon Post office in Beirut, photos given by my dear friend Nora Schneider (photos made in February 2019). You can find more information about Lebanon post here: https://www.libanpost.com/english/about-us/overview