I'm not kidding, since you wanted proof, I provided the actual spam-message. Also, I'm not kidding about it being a crime. Sending spam can get somebody fined up to 450.000 euro. About the spam, decoded, it comes from 50.73.45.250 which is the same IP-address as casascius.com, and it is an advertisement for that site. It can be verified with PGP, and so is no fake, or a phish for another site or something. The text decoded says:

Sorry to be sending e-mail to the Mt.Gox leak list.

Please be advised that a recent e-mail purporting to be from me regarding Casascius Physical
Bitcoins is fake and leads to a phishing site.  Don't give out your info unless you're sure you're
at the right place.

The real Casascius Physical Bitcoins website is at https://www.casascius.com.
If you do not know how to verify my PGP signature, consider looking me up on the forums to make
sure you have the right address and are not being phished.

Sorry for the hassle and the inconvenience, but I suppose this was going to happen sooner or later.

Mike Caldwell