Lets put it this way I wouldn't even waste time checking, delete all Spam, especially one like this when you obviously haven't used UPS to warrant an invoice.
It is almost certainly a phishing exercise of sorts (not uncommon, the only difference being the trickery used), designed I believe to get a response, that response (irate) would possibly lead you to click a link in the email to complain and that could really get you in trouble.
At best it confirms your email address is live and you get much more spam. At worst you could get infected by visiting any link on the email. Never open attachments or click links in unsolicited emails.
