Q: What is the rectangle with the hard to read characters for?

A: It is a security measure. "Spammers" use software to "crawl" the web in order to "harvest" e-mail addresses. If I list your address or provide a simple link, they can spam you and add you to their database(s). They can then not only spam you endlessly, but sell your address to other spammers who will do the same. The graphic cannot be read by spammer's "spiders" or "bots", but can be figured out by people.

To get an inside look into the world of spamming, here is alink to a PDF by a legitimate anti-virus software company.  Why spammers spam  Just make sure you're not already worked up before you read it. You probably will be after a few pages.