Have a way to log emails.

Have a way to forward emails (both sent and received) to the daatbase. Perhaps use tag lines in the Subject to id the event it should be attached to.
For example, I receive an email about a show coming up in two weeks. I forward it to something like mytourelvis1234xyz@eventric.com and then in the subject line I write 4_15_2014 Megadome.
This way I can keep a log of all the dialogues I wish to keep track of pertaining to that date.