Thanks for the replies. I thought it fell under hazardous materials to mail.
Edit: As I thought,
it does and is listed under section 11.7, Other Restricted and Nonmailable Matter:
Quote:
Intoxicating Liquor
A potable beverage is nonmailable if it is of 0.5% or more alcoholic content by weight, which is taxable under Chapter 51, Internal Revenue Service Code. The product may be mailed if it conforms to applicable requirements of the Internal Revenue Service and Food and Drug Administration and is not an alcoholic beverage, poisonous, or flammable.
This is what I had recalled so I was wondering if people had done it. It seems that this is the case so it looks like they don't really enforce/check.