I have now run across a couple of instances of a website URL getting included in the text spam type email, and the result was that gmail began to block delivery of ANY email that contained the URL in the text of the message.
For example, a black hat spammer sends 100s of emails per day about widget.com on a continuing basis for a few weeks. Soon Google starts to block all emails that are destined for Gmail accounts from Widget.com. Now all customers who receive sales, support or promotional emails from Widget.com are now getting blocked by Gmail.
Black Hat success! Seems to be an exploit in my view.
