Phishing (see http://www.antiphishing.org/ for info) uses a very simple
mechanism to trick users into clicking through to an evil Web site. They use
HTML mail with links like this:

  <a href="http://evil.example.com/">http://trusted.example.net/</a>

That is, they use a trusted (or trusted-looking) URL as the text of a link, but
the href is actually for an evil, untrusted link.

It is an automatable task to highlight in some visual way -- or even give an
"are you sure?" dialog message -- links in HTML messages that have text that a)
looks like an URL and b) is not equal URL-wise to the HREF value. I believe
there is already code in Evolution to do these two matches.

Although the traditional Evolution user is pretty sophisticated and net-savvy,
this would still be helpful for less sophisticated email novices.