A Craigslist user sent this piece of intel. It appears that scam artists prefer to use fresnomail.com. If you receive an offer from anyone with fresnomail.com at the end of their email is very cautious.
7/1/2008
I just got a response from Lauretta Coronado that is word-for-word the message sent to by Robert Adams. Her email address is fresnomail.com too, I did a quick Google search and it seems like a lot of spammers use fresnomail.com. Thanks for setting up this site.

OSHA Poster Scheme
Attention Business Owners and Employees,

If traveling or door to door salesmen approach your business with an attempt to sell OSHA Posters, please know that this tactic is a complete scam. While it may be easy to fall for their high pressure sales pitch, just know that it is completely unnecessary for them to even be at your place of business. OSHA offers free official posters so your business will be in compliance. If you do not have an annual compliance poster, please visit OSHA's website and order one.