Top email-related discovery cases

What would you consider the most important email-related discovery cases? Full disclosure: I am asking both for the AIIM Email Certificate Program and for some presentations I have coming up. I have a list, but I don't want to share it out of fear of prejudicing any potential responses. If you have a case or a list, post as a comment or send it to me via email.

Note: My list is all US cases; if you know of seminal, important cases outside the US, please forward those as well.

Tags: email, e-mail, discovery, aiim, certificate program