In May, the United States Postal Service will invite select customers to participate in a mail sale.

The sale begins July 1, ending September 30, 2010.

Criteria to have access to the 30% credit applied to Standard Mail service is to show a 5% increase in 2009 mail volume and move a minimum of 350,000 pieces during the sales period.

This is not the first sale for the USPS. In 2006, legislation was enacted to allow the Post Office to provide sales to boost revenues.