I just don't understand how someone uses e-mail for as long as he must have been (at LEAST 15 years, likely more like 20 or so) and doesn't realize something so basic about it. How long has he been worrying about how to capitalize e-mail addresses?
And I mean, yes, technically the first part of the e-mail can be case sensitive, but I've NEVER seen an e-mail system that actually treats them that way or lets you set up mailbox AbC@domain and aBc@domain at the same time. That's just asking for trouble.