Like a parasite, unions will eventually always kill the host.
The postal workers have a choice. Allow their hours and benefits to be adjusted or join the ranks of the unemployed.
There are many things the post office can do, but if they do not control the cost of labor, then nothing else will work.
Folks, the Post Office management signed those contracts with the unions. The unions did not hold a gun to their heads, management agreed. With respect to pensions. A reasonably simple calculation based on the number of years that a person works (about 45) and the number of hours in a work year (2080) one can easily figure out what a reasonable pension can be. The problem is that reason has flown out the door. We need reasonable values and a person has to save for retirement.