Hi, my name is Jenna.
You don't know me, but we were in Hawaii together. This is going to sound kind of strange, but I saw you mail a postcard and it fell out of the mailbox when you walked away. I picked it up and when I saw that it had the address of where it was going to and your next address I wanted to make sure you knew that I sent it for you. I hope you're enjoying your vacation in Bali. Happy postcard-ing