"If it’s not legal will it be detected?"
No. Sending marijuana through the mail has never been and will never be a good idea. The act is risky, with severe consequences, and the chances of getting caught are higher than ever, as the post office is constantly looking for suspicious packages that may contain some of Colorado or Washington’s coveted bud.There are 1,614 inspectors at United States Post Offices. They use K-9’s to assist in the searches, but it is like searching for a needle in a hay stack. However, it hasn’t stopped 1,278 people from going to jail in 2009, for instance, for trying to mail marijuana. The U.S. Postal Service offers a $50,000 reward for information leading to the conviction of people trying to mail marijuana via the U.S. mail system.