You will not believe what happened to my invitations! Since we are having a short engagement and I have horrible handwritting, I thought "I'll just print labels rather than writing all the names and addresses". Bad idea!
I loaded the list into a site to create the labels and when they printed, the wrong names came with the wrong addresses for about 25% of the file. I didn't notice. One of my sorority sisters got invites addressed to my boss and his family, etc. It was nuts! I've now spent hours tracking down invites and explaining to everyone what happened.
While this is completely laughable - and believe me, I do laugh that this happened - I post this as a warning. Check your invites.