Got similar postcard. American Airlines, however they are not the promotion.
Googled it and got scam alerts. I was extremely skeptical to begin with.
Got a postcard with Delta (airlines) logo saying I've been selected to receive free airfare for 2. This is the number printed on the postcard. I found a scam warning on the CT Consumer Protection Agency website confirming that it's a scam to collect personal information or pressure people to sign up for high-priced subscriptions or travel clubs: