I can see why a lot of people would not consider this a classic - until they see the forward-facing arrow created in the negative space between the “E” and the “x”.
Of course this subtlety has been a bit of an issue. The logo designer (who has a great name), Lindon Leader, said that FedEx’s PR firm wanted to make the arrow more obvious, like fill it in with another colour. But of course this would miss the point. What makes this a great logo is what is not obviously there, not what is.
Have a nice weekend,