The player can just reprint the document. This alone has allowed me to really personalize spell lists. And spell components can be looked up and recorded away from the game session where time is, again, in short supply. Frequent use of e-mail can allow players to go back and recall what was going on, even if summaries and calenders are not being used. The more e-mail you use, the more this is so.
Logs can also help clear up possibly disastrous mistakes.
Here's a trick I once pulled using e-mail. A character who had a leadership role in a part of my campaign world was looking for a new commander of his military. I prepared two letters apiece for four candidates. The first letter was glowingly positive, the second one was biased in the opposite direction. Reading these letters, going over them, and deciding on which man to select was best handled away from the gaming table.