Does appleutd@xmr3.com belong to the Apple up to date program?
I wonder if you signed up for their Up to Date Program on a web page pretending to be the Apple website. That PDF is most likely a scam, do not open it--It could execute some malicious code. In the last seven years I have yet to see e-mail communication from Apple that does not come from apple.com. Also, I think all of their invoicing is done by using HTML-formatted e-mail messages sent to your Apple ID, not PDF's. Hope this helps.