Looks like it is a thing in some libraries: https://www.google.com/search?client=firefox-b-1-d&q=book+by+mail+library https://www.google.com/search?client=firef

Looks like it is a thing in some libraries: https://www.google.com/search?client=firefox-b-1-d&q=book+by+mail+library https://www.google.com/search?client=firefox-b-1-d&q=book+by...