The U.S. Postal Service creed says, "Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds."

But on Aug. 1, the Postal Service may do much more than fail to deliver the mail. It may default on billions of dollars in health benefits for its future retirees.

Congressional action is all that can stop the default, and lawmakers likely won't take action. The House is getting ready to leave for its August recess.

The Postal Service blames its money problems on declining mail volumes and the requirement to set aside billions for its future retirees.