This is a joke. I'm constantly running up against the limit, and I don't do a lot of email. In this day of giant (Microsoft) documents being sent as attachments, it's easy to rack up 100MB of email in no time. I have 10 emails with attachments that total 30MB in my Inbox right now. Add to that the 15MB of Calendar entries (and I have an fairly empty calendar), and 100MB is nothing.
I just want to gather four other employees, get $30 a piece from each of us, go to Fryes, buy a 1 Terabyte hard drive, give it to IT and say "put our Outlook Mailboxes on this and leave us alone". Folks, we're supposed to be a top IT company here...