"There are some “grey area” emails, which fall somewhere between spam and legitimate mail, and sometimes there can be something very inconspicuous in the mail that can tip the balance in the mind of a recipient. Quoting antispam law in the body of the email and claiming that the email adheres to the law is proving to be a popular technique when it comes to painting “grey area” spam white."
 Whitewashed Spam – How Antispam Laws Are Helping Spammers