Just try to convince yourself that they may have good reasons. Maybe something has come up in their lives and you will still get that email later. If not just tell yourself that it was not meant to be and move on. Good luck!
Twelve years later I was spending a lot of time back in my college town because my old roommate was terminally ill. By then I was married. We ran into each other at Mass and rekindled a friendship over the next few months until my roommate died. We stayed in loose contact afterwards. The first thing I realized is that she and I would have never made it as a couple. We were completely mismatched. But we became good friends. She and my (then) wife hit it off. I liked her husband. Odd how things work out. They say "rejection is God's protection". That's so right.