This is what happens when your business is: 1) Based on an out-dated model that has failed to keep up with technology; and 2) Is heavily unionized.

The U.S. Postal Service said it ended another fiscal year with billions of dollars in losses, an expected announcement that continued to illustrate the agency’s shaky financial picture.

The Postal Service said it lost $5.1 billion through Sept. 30 and that the loss would have hit $10.6 billion without recent legislation allowing it to delay a required annual $5.5 billion payment into a fund for future retiree health benefits. But the payment postponed by Congress is now due by Nov. 18, and the agency repeated that it could run out of cash by the end of fiscal 2012 without congressional action.

Two things:

1) It goes to show the Post Office isn’t losing money because of that retiree fund mandate — it’s losing money because its business model sucks.

2) The mandate exists because benefits promised to unions tend to get insane and taxpayers would prefer to not have to bail out the union luxury retirement benefits.

Congress is now considering closing branches, shortening the mail delivery week to five days, and venture into non-mail services, whatever that means for a postal service.