[otrs] Email ticket integration question

Hello, My users are now using the web interface to crate tickets and their login id is their email address. I'd like they also were able to use the email to create them, but I don't know if the system would recognize them and show them the email tickets in theirs customer web interface. Could anybody who is using this feature tell me how this works? And the question for the prize: If so, does anybody know the part of the code that analyzes the user who the tickets belongs to? Thanks in advance