I’m designing a #10 envelope and need somebody at the USPS to review my design before printing 10,000 pieces.

Mailpiece Design Analyst: Mailpiece Design Analysts (MDA) are postal employees specially trained to answer your questions regarding mailpiece design. These employees provide advice and issue rulings regarding acceptability for automated rates. MDAs provide technical assistance on mailpiece design to envelope manufacturers, printers, advertising agencies, and graphic designers.

Find one based on your ZIP code: http://pe.usps.gov/mpdesign/mpdfr_mda_intro.asp