HTML Emails & Craigslist relay

[SimbaLion]

I recently switched to using HTML e-mails. When I click compose to start a message it looks fine, but when I respond to an email thru craigslist, the HTML in my signature is changed, with a 'Links' section and

• numbered citations. In the sent email, the
• appear as links, in addition to the 'links' section..
  
  Can someone explain what's going on? I've been using plain text emails for years.
  
  UPDATE: I realized it must be the mailto: link on the craigslist site that's causing the trouble, so I inspected it. It seems that it passes some arguments to the mail app, and I suspect that is where the problem originates. Here is the link without anchor tags:
  
  href="mailto:g3h2p-5117433602%40serv.craigslist.org?subject=Affordable%20%26%20Professional%20Graphic%2FWeb%20Design%20%26%20Development%21%21&body=%0A%0Ahttp://athensga.craigslist.org/cps/5117433602.html%0a" class="mailapp"
  
  Is it the body section that causes the HTML to break? Is there any way to tell roundcube to ignore the body argument in mailto: links?