As far as I understand, the quest Divine Conundrum can be started in two ways: by reading the note from the mail, or from collections UI. Since the note is bound and it can not be put in the bank, all the other characters have to start the quest the second way, leaving them unable to collect Eidetic Memory entry.
Is there a way to get the book later, or this is just a usual sloppiness when it comes to book collecting?