You can read the list of the top vendors to USPS here. IBM was #11 last year, down two spots.
Very American company when it comes to getting a fat check from government . . .
H/t to savethepostoffice.com
[Note: Interesting to see "free market" FedEx keep the top spot for the tenth year in a row. USPS basically delivers all the packages that FedEx wouldn't be able to make money on . . . ]