[Koha] Koha email question.

Hi all I have question, does koha can sent automatic mail to patrons when books on hold is avainable? I mean patrons reserve books, and when it become available, he got message. Or another situation, patron check out books, and in two days he must return or renew it. He got mail please return or renew item/books. It is posible? If yes when i can start find option to config/set up this.?