The "Three Rs" take on a more modern meaning today as the U.S. Postal Service makes it easier for Post Office Box customers across the country to recycle their mail.

"Read, Respond, Recycle" is the banner under which the Postal Service will reach out to postal customers with a convenient, environmentally responsible alternative to bringing home or discarding their PO Box mail.

The Post Office Box Lobby Recycling program is expanding to 1,844 new sites, bringing the total of participating post offices to more than 5,900. The program builds on the success of similar programs that have been ongoing in the northeast part of the United States for more than 10 years.

Lobby recycling helps divert paper waste from landfills, reducing the amount of virgin fiber from trees needed to produce more paper and eliminating greenhouse gas emissions from solid waste disposal.

Secure recycling bins are placed in Post Office lobbies. All bins are locked with a key and the opening is slim -- about the width of a news magazine. PO Box customers are encouraged to remove and open their mail (read), take whatever action is necessary (respond) and simply place the rest of their mail into the bin (recycle).

This program has been thoroughly tested and presents no risk to mail security or customer privacy and does not effect postal operations or costs, according to Sam Pulcrano, vice president, Sustainability.

In 2008, more than $12 million in revenue was generated by selling recyclables as raw materials, diverting tons of wastepaper, cardboard, cans, plastics and other materials from landfills.

Each year, the Postal Service purchases more than $200 million in products containing recycled content. Many of the containers that hold and move mail in the system are made from recycled materials, as are stamped envelopes, postcards, stamp booklet covers -- even the adhesive used in postage stamps is biodegradable.

The Postal Service is the only shipping company in the country to earn Cradle to Cradle certification for all Priority Mail and Express Mail packages and envelopes based on the environmental attributes of the materials used in the packaging.

PO Box Lobby Recycling is one more way the Postal Service is demonstrating its commitment to environmental stewardship. The Postal Service has a long and proud environmental record, has won more than 70 environmental awards and works daily to create a culture of conservation among its 685,000 employees.

A complete list of participating post offices can be found at Earth911.com, using the word "mail" in the search engine. The list is sorted by ZIP Code.