diff --git a/mailnews/base/resources/content/msgMail3PaneWindow.js b/mailnews/base/resources/content/msgMail3PaneWindow.js
index b1a7854d1f7f..39dc5f3f762c 100644
--- a/mailnews/base/resources/content/msgMail3PaneWindow.js
+++ b/mailnews/base/resources/content/msgMail3PaneWindow.js
@@ -1075,7 +1075,16 @@ function GetFirstSelectedMessage()
         // Use this instead of gDBView.URIForFirstSelectedMessage, else it
         // will return the currentIndex message instead of the highlighted
         // message.
-        return GetSelectedMessages()[0];
+        //
+        // note, there may not be any selected messages
+        //
+        // XXX todo
+        // is this inefficient when we've got a lot of message selected?
+        var selectedMessages = GetSelectedMessages();
+        if (selectedMessages)
+          return selectedMessages[0];
+        else
+          return null;
     }
     catch (ex) {
         return null;