The Help Book files in my app were composed in HTML. In XCode 4 all of the links work except for links that should open Mail so my customers can E-mail me. In older versions of XCode when they clicked on links like these: <a href="mailto:firstname.lastname@example.org?Subject=appname">E-mail support</a> It opened Mail. Now it doesn't. Can anyone tell me why and suggest a remedy? Update: I tried composing this page in BBEdit as HTML 5. I created it in Text Edit and saved it as HTML. I created a page with iWeb. I tried a lowercase 's' in "subject". These all create html with a capital 'S' in "Subject". I tried it with out the "?subject". It works in two browsers, all of the HTML editors, in fact in everything except in my help book. ???