Some people add crap like this to the end of their messages.
This email and any attachments thereto may contain private, confidential, and privileged material for the sole use of the intended recipient. Any review, copying, or distribution of this email (or any attachments thereto) by others is strictly prohibited. If you are not the intended recipient, please contact the sender immediately and permanently delete the original and any copies of this email and any attachments thereto.
I think this should read as follows:
This email and any attachments thereto may contain private, confidential, and privileged material. Since I sent it to you I recognize fully that there is no way for me to prove beyond doubt in a court of law that I didn’t actually intend to send it to you since your address is in the To:, CC: or BCC: field. Any review, copying, or distribution of this email (or any attachments thereto) by others is not something which I relish, but I can do nothing about it. If you are not the intended recipient, I’d really appreciate it if you contacted me to let me know of my mistake (I am an idiot, clearly, since I … errr… add this crap to ALL my emails) and if you could not keep a copy of it, that would also make me happy. I also wish to apologize profusely for the fact that in the course of an email thread, I will keep adding, automatically, copies of this stupid legal bullshit to every response. Since I am clearly an argumentative type, which means you probably have about 400 copies of this before you’re going to get any kind of resolution, so I apologize for that too. I also apologize for being too stupid to put this crap on a website somewhere and just put the URL in my sig, or maybe just having something witty that might actually endear me to you instead of just further harrassing you.