I mailed my invitations out on Friday, and yesterday I received an empty RSVP envelope. I'm guessing that the entire invitation opened up and the envelope fell out, since there's no way someone would have been able to send an RSVP back so quickly. I've heard from a couple people that they received their invitations, so hopefully it was just this one. Unfortunately I won't know who it was supposed to go to until after the RSVP deadline, unless someone mentions they didn't receive an invite. Ugh. Did this happen to anyone else?