In Washington D.C.'s main Post Office, mail senders and receivers seem happy with the service.

But what they're doing is almost certain to change

Blame it on the Internet.

"In the electronic age maybe people aren't using as much mail service as before so that's probably changed things a lot," says Julie Eddinger.

In fact online banking, and people sending email,along with the recession, pushed mail volume down 13% in the last fiscal year.

And the Postal Service lost almost $4 billion.

With even tougher times forecast, the agency's talking about cutting services.

Saturday delivery days could go away, post offices could close, and rates could rise.

Some blame lack of competition, and union-protected pay.

The agency does want more leeway in union negotiations, particularly in addressing the soaring costs of worker and retiree health care.