FILE- In this Dec. 14, 2017, file photo, boxes for sorted mail are stacked at the main post office in Omaha, Neb. (AP Photo/Nati Harnik, File)
FILE- In this Dec. 14, 2017, file photo, boxes for sorted mail are stacked at the main post office in Omaha, Neb. (AP Photo/Nati Harnik, File)
FILE- In this Dec. 14, 2017, file photo, boxes for sorted mail are stacked at the main post office in Omaha, Neb. (AP Photo/Nati Harnik, File)