Not all email messages with HTML links inside them are evildoers. Some are quite innocent, such as the links posted in the above paragraph - there isn't any identifying information saying you are coming from Web Informant in these links, you can see quite plainly. They just contain the links you need to go directly from the information in the email to the specific web page that they are discussing. That is the way it is supposed to be, until the email marketing community seized upon this method to do some of their dirty work. You see, being in the email newsletter business myself, it is hard to keep track of your subscribers.
People change email addresses quicker than they change their underwear sometimes.
Email subscribers are also bad about notifying their list owners of the new address. Since the addresses go stale so easily, email marketeers want some way to verify that real live humans are responding to their missives. Given how much time I have spent unsubbing some of my own subscribers, I can certainly understand this last point. Back in those dark days, it was rare to see anyone sending out such messages, and indeed I ran into a few problems with the primitive email clients that we all used then. But still, I got enough complaints and enough trouble that eventually I stopped the practice, about a year after I began sending around the newsletters.