add: msgWindow.rootDocShell.allowAuth = true; 
context: function InitMsgWindow(){  msgWindow.messagePaneController = new nsMessagePaneController();  msgWindow.statusFeedback = statusFeedback;  msgWindow.msgHeaderSink = messageHeaderSink;  msgWindow.SetDOMWindow(window);  mailSession.AddMsgWindow(msgWindow);  var messagepane = document.getElementById("messagepane");  messagepane.docShell.allowAuth = false;}
meta: 8395	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8395/f088f54df36ecaf7c088d49128bf7c4441965b2b/mailWindow.js/clean/mailnews/base/resources/content/mailWindow.js