My understanding (as related to me by a former FedEx manager) is that when FedEx underwent their rebranding from Federal Express, they utilized several different sources to come up with new logos.
One of those sources was a class of marketing students at the University of Memphis. Apparently they were the ones to create the logo/branding that was finally accepted. FedEx and the university have created an ongoing relationship in the years since.
That's what I've been told... can't confirm it 100%, but I think it's a cool story.