Bill Margaritis, VP of global communications and IR at FedEx, makes a point of publicly thanking Ketchum, the company's long-running AOR, for its work. He did so recently at an industry awards show where he was honored; it's kind of a thing with him.
Most clients don't spend a lot of time thanking their agencies in this way, though that in itself is not necessarily a sign of trouble. But those who work on the account routinely testify that FedEx is ...