diff --git a/mailnews/base/resources/content/mail3PaneWindowCommands.js b/mailnews/base/resources/content/mail3PaneWindowCommands.js
index 30d353b674e..951613a7054 100644
--- a/mailnews/base/resources/content/mail3PaneWindowCommands.js
+++ b/mailnews/base/resources/content/mail3PaneWindowCommands.js
@@ -760,6 +760,9 @@ function SetupCommandUpdateHandlers()
 function IsSendUnsentMsgsEnabled(folderResource)
 {
   var identity;
+
+  if (messenger.sendingUnsentMsgs) // if we're currently sending unsent msgs, disable this cmd.
+    return false;
   try {
     if (folderResource) {
       // if folderResource is non-null, it is