“The most greeting cards sent from a single location at one time is 2,984 and was achieved by Stampin’ Up! (USA) at the Salt Palace Convention Center in Salt Lake City, Utah, USA, on 18 July 2013.
Every card was unique, being hand-made by a participant. Cards were collected for delivery by the United States Postal Service.” I think the post office was very, very busy on Friday, July 19, 2013.
It’s posted on the GUINNESS WORLD RECORDS website. Check it out! We’re famous!