We mixed up the gifts and cards!!!

This is why you ask your 11 year-old second cousin to stand by the gift area with a roll of Scotch Tape. She tapes cards onto gifts. This is a simple deal that prevents this situation. I would suggest that you send out a lot of emails and be honest. "We lost the card, gift tag. We are so sorry as we want to personally acknowledge your gift." Make a few polite inquiries. Maybe Aunt Agnes remembers who gave you the towels or Uncle Ernie can tell you who gave you the toaster (assuming he wasn't tanked at the time!) Good Luck.

Oh no! The same thing happened to us at our engagement party!! It was an outdoor garden party and it started to rain at the very end of the night, so we were running all the presents to the car and some of the cards got mixed up. It was a nightmare, but we are going with the generic thank you note approach. There was one present that was so amazing and thoughtful (a wood cutting board that a guest had burned our wedding date and names into along with some beautiful designs) that we just HAD to find out who got it for us! I asked my future mother in law if she could sneakily ask around since we had narrowed it down to two guests.