Shares of FedEx (NYSE: FDX) were down 4.9% as of 2 p.m. EDT on Tuesday after the courier delivery services giant announced mixed results for the 2019 fiscal first quarter.More specifically, FedEx's quarterly revenue climbed 11.8% year over year to $17.1 billion, which translated to adjusted (non-GAAP) earnings of $3.46 per diluted share, up from $2.51 in the year-ago period.