Oh hey I had one of those last week. Months ago someone contacted me for a memo so I sent it to them and the email address that they specified it needed to go to. The email address bounced back to me because it was unknown. I forwarded that email to the person asking what they wanted me to do. Radio silence.

Cut to last week when they sent an email to a bunch of people plus my boss saying "since I still don't have the memo..." so I replied all and attached both the email I sent initially and the second forward and my response was "wow you don't have a memo? that's rough."