diff --git a/kmail/kmmainwidget.cpp b/kmail/kmmainwidget.cpp
index 0d845225..1d2661f5 100644
--- a/kmail/kmmainwidget.cpp
+++ b/kmail/kmmainwidget.cpp
@@ -2438,6 +2438,7 @@ void KMMainWidget::slotMsgPopup(KMMessage&, const KURL &aUrl, const TQPoint& aPo
     viewSourceAction()->plug(menu);
     if(mMsgView) {
       mMsgView->toggleFixFontAction()->plug(menu);
+      mMsgView->toggleMimePartTreeAction()->plug(menu);
     }
     menu->insertSeparator();
     mPrintAction->plug( menu );
diff --git a/kmail/kmreadermainwin.cpp b/kmail/kmreadermainwin.cpp
index 6694ba3f..6257ba93 100644
--- a/kmail/kmreadermainwin.cpp
+++ b/kmail/kmreadermainwin.cpp
@@ -509,6 +509,7 @@ void KMReaderMainWin::slotMsgPopup(KMMessage &aMsg, const KURL &aUrl, const TQPo
     menu->insertSeparator();
     mViewSourceAction->plug( menu );
     mReaderWin->toggleFixFontAction()->plug( menu );
+	mReaderWin->toggleMimePartTreeAction()->plug( menu );
     menu->insertSeparator();
     mPrintAction->plug( menu );
     mSaveAsAction->plug( menu );
diff --git a/kmail/kmreaderwin.cpp b/kmail/kmreaderwin.cpp
index b3c43570..1b6ca487 100644
--- a/kmail/kmreaderwin.cpp
+++ b/kmail/kmreaderwin.cpp
@@ -618,6 +618,11 @@ void KMReaderWin::createActions( TDEActionCollection * ac ) {
                                             Key_X, TQT_TQOBJECT(this), TQT_SLOT(slotToggleFixedFont()),
                                             ac, "toggle_fixedfont" );
 
+  mToggleMimePartTreeAction = new TDEToggleAction( i18n("Show Message Structure"),
+                                            0, ac, "toggle_mimeparttree" );
+  connect(mToggleMimePartTreeAction, TQT_SIGNAL(toggled(bool)),
+          TQT_TQOBJECT(this), TQT_SLOT(slotToggleMimePartTree()));
+
   mStartIMChatAction = new TDEAction( i18n("Chat &With..."), 0, TQT_TQOBJECT(this),
 				    TQT_SLOT(slotIMChat()), ac, "start_im_chat" );
 }
@@ -1444,6 +1449,7 @@ int KMReaderWin::pointsToPixel(int pointSize) const
 
 //-----------------------------------------------------------------------------
 void KMReaderWin::showHideMimeTree( bool isPlainTextTopLevel ) {
+  mIsPlainText = isPlainTextTopLevel;
   if ( mMimeTreeMode == 2 ||
        ( mMimeTreeMode == 1 && !isPlainTextTopLevel ) )
     mMimePartTree->show();
@@ -1453,6 +1459,9 @@ void KMReaderWin::showHideMimeTree( bool isPlainTextTopLevel ) {
     saveSplitterSizes( reader );
     mMimePartTree->hide();
   }
+  if ( mToggleMimePartTreeAction->isChecked() != mMimePartTree->isVisible() ) {
+    mToggleMimePartTreeAction->setChecked( mMimePartTree->isVisible() );
+  }
 }
 
 void KMReaderWin::displayMessage() {
@@ -2134,6 +2143,17 @@ void KMReaderWin::slotToggleFixedFont()
 }
 
 
+//-----------------------------------------------------------------------------
+void KMReaderWin::slotToggleMimePartTree()
+{
+  if ( mToggleMimePartTreeAction->isChecked() ) {
+    mMimeTreeMode = 2;  // always
+  } else {
+    mMimeTreeMode = 0;  // never
+  }
+  showHideMimeTree();
+}
+
 //-----------------------------------------------------------------------------
 void KMReaderWin::slotCopySelectedText()
 {
diff --git a/kmail/kmreaderwin.h b/kmail/kmreaderwin.h
index 81256e8c..0495041b 100644
--- a/kmail/kmreaderwin.h
+++ b/kmail/kmreaderwin.h
@@ -5,6 +5,7 @@
 #ifndef KMREADERWIN_H
 #define KMREADERWIN_H
 
+#include <tdeactionclasses.h>
 #include <tqwidget.h>
 #include <tqtimer.h>
 #include <tqstringlist.h>
@@ -256,6 +257,7 @@ public:
   TDEAction *urlOpenAction() { return mUrlOpenAction; }
   TDEAction *urlSaveAsAction() { return mUrlSaveAsAction; }
   TDEAction *addBookmarksAction() { return mAddBookmarksAction;}
+  TDEAction *toggleMimePartTreeAction() { return mToggleMimePartTreeAction; }
   TDEAction *startImChatAction() { return mStartIMChatAction; }
   // This function returns the complete data that were in this
   // message parts - *after* all encryption has been removed that
@@ -398,6 +400,8 @@ public slots:
   /** The user toggled the "Fixed Font" flag from the view menu. */
   void slotToggleFixedFont();
 
+  void slotToggleMimePartTree();
+
   /** Copy the selected text to the clipboard */
   void slotCopySelectedText();
 
@@ -594,6 +598,7 @@ private:
   TDEToggleAction *mHeaderOnlyAttachmentsAction;
   TDESelectAction *mSelectEncodingAction;
   TDEToggleAction *mToggleFixFontAction;
+  TDEToggleAction *mToggleMimePartTreeAction;
 
   KURL mHoveredUrl;
   KURL mClickedUrl;