The relevant section for us…
(Sec. 404) Authorizes the mailing of wine and beer by a licensed winery or brewery in accordance with the laws of the state, territory, or district where the addressee or authorized agent takes delivery. Requires USPS to issue regulations requiring: (1) the delivery of wine and beer directly to the addressee or agent; (2) the addressee to be at least 21 years of age; and (3) the individual who takes delivery to present a valid, government-issued photo identification.
Washington Post write-up that does not mention the beer piece.
via Library of Congress.