“Thanks for your interest, but we’ve decided to go with another candidate.”
This is a crappy email to receive, particularly when you thought you had it in the bag. The exceptional opportunity that you believed was a perfect fit is no longer on the table.
It seemed like an offer was definitely in the works, too; after all, you’d sent them references upon request, and even briefly chatted about possible compensation. Plus, you bonded with the hiring manager—you can’t have made that up.