UPS Warning: legal bluff, or legit?

I recently ordered a PC from an online vendor; it shipped yesterday, and I got an email from UPS with the following warning at the bottom:

Now, if they had sent this to me in error (say they got my email wrong for some reason), and I didn’t ask for it, do they have a legal leg to stand on if I decide I want to distribute or disseminate the message?

See my disparaging comments about this here:
http://boards.straightdope.com/sdmb/showthread.php?threadid=90037

It’d depend on the court. However, in general, there must be an agreement by both sides in order for a contract to be legal. Merely receving a document does not require that you abide by its terms.

Suppose, for instance, UPS sent you an e-mail that read: “By receiving this e-mail, you agree to pay us $100.” Obviously, they can’t do that.

If you forwarded the message, they could try to sue you, but it’s not likely they’d win a judgment. Still, you never know how the judge might ultimately rule.