add: if (("content-type" in currentHeaderData) && /application\/x-pkcs7-(mime|signature)/ .test(currentHeaderData["content-type"].headerValue)) return false;  
context: function CanDetachAttachments(){  var uri = GetLoadedMessage();  return !IsNewsMessage(uri) && (!IsImapMessage(uri) || CheckOnline());}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/9421/c26ebbf76f281d2214aacdcb5c2fde74b9bf2495/msgHdrViewOverlay.js/clean/mailnews/base/resources/content/msgHdrViewOverlay.js