When you are talking about the author of a book or play, you say that the book is by someone or written by someone.
1. …three books by a great Australian writer.
2. …a collection of pieces by Mozart.
When talking about the person who has written you a letter or sent a message to you, you say that the letter or message is from that person.
3. A few days later in Chicago the Capones received a message from Vito Corleone.