Big brown mail

I think you might be referring to the "Brown Mail" or "Brown Package" that many people are familiar with!

The "Brown Mail" is a colloquial term used to describe the United States Postal Service (USPS) mail delivery service, which is characterized by the brown color of the mail trucks and the brown packaging of the mail itself.

The USPS is responsible for delivering mail and packages to millions of addresses across the United States, and the brown color of their vehicles and packaging has become synonymous with the service.

Is there anything specific you'd like to know about the USPS or mail delivery in general?