First class mail

"The U.S. Post Office is the only entity allowed by federal law to deliver first class mail to your mailbox. In fact, Fedex and UPS are strictly prohibited from delivering "non-urgent" letters".

See also

• United States Postal Service
• Bulk mail

Cooper, Rory. Obamacare: The “Post Office” of Health Care Plans. Heritage Foundation. 11 August 2009. Accessed 15 January 2010.

Hawkins, John. Our Health Care System Is Going To Be Like The Post Office?. Right Wing News. 12 August 2009. Accessed 15 January 2010.