diff --git a/src/kmmainwidget.cpp b/src/kmmainwidget.cpp
--- a/src/kmmainwidget.cpp
+++ b/src/kmmainwidget.cpp
@@ -3938,10 +3938,7 @@
 
     const bool isInTrashFolder = (mCurrentFolderSettings && CommonKernel->folderIsTrash(mCurrentCollection));
     QAction *moveToTrash = akonadiStandardAction(Akonadi::StandardMailActionManager::MoveToTrash);
-    moveToTrash->setText(isInTrashFolder ? i18nc("@action Hard delete, bypassing trash", "&Delete") : i18n("&Move to Trash"));
-    moveToTrash->setIcon(isInTrashFolder ? QIcon::fromTheme(QStringLiteral("edit-delete")) : QIcon::fromTheme(QStringLiteral("user-trash")));
-    //Use same text as in Text property. Change it in kf5
-    moveToTrash->setToolTip(isInTrashFolder ? i18nc("@action Hard delete, bypassing trash", "Delete") : i18n("Move to Trash"));
+    KMail::Util::setActionTrashOrDelete(moveToTrash, isInTrashFolder);
 
     mTrashThreadAction->setIcon(isInTrashFolder ? QIcon::fromTheme(QStringLiteral("edit-delete")) : QIcon::fromTheme(QStringLiteral("user-trash")));
     mTrashThreadAction->setText(isInTrashFolder ? i18n("Delete T&hread") : i18n("M&ove Thread to Trash"));
diff --git a/src/kmreadermainwin.cpp b/src/kmreadermainwin.cpp
--- a/src/kmreadermainwin.cpp
+++ b/src/kmreadermainwin.cpp
@@ -160,6 +160,9 @@
         mReaderWin->viewer()->headerStylePlugin()->headerStyle()->setReadOnlyMessage(!canChange);
     }
 
+    const bool isInTrashFolder = mParentCollection.isValid() ? CommonKernel->folderIsTrash(mParentCollection) : false;
+    QAction *moveToTrash = actionCollection()->action(QStringLiteral("move_to_trash"));
+    KMail::Util::setActionTrashOrDelete(moveToTrash, isInTrashFolder);
     menuBar()->show();
     toolBar(QStringLiteral("mainToolBar"))->show();
 }
diff --git a/src/util.h b/src/util.h
--- a/src/util.h
+++ b/src/util.h
@@ -78,6 +78,13 @@
 void lastEncryptAndSignState(bool &lastEncrypt, bool &lastSign, const KMime::Message::Ptr &msg);
 
 void addQActionHelpText(QAction *action, const QString &text);
+
+/**
+     * Set an action's text, icon etc. as appropriate for whether a message is
+     * in the trash folder (delete permanently) or any other (move to trash).
+     */
+void setActionTrashOrDelete(QAction *action, bool isInTrashFolder);
+
 }
 }
 
diff --git a/src/util.cpp b/src/util.cpp
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -44,6 +44,7 @@
 
 #include <kmime/kmime_message.h>
 #include <kmessagebox.h>
+#include <klocalizedstring.h>
 #include "kmail_debug.h"
 
 #include <QAction>
@@ -176,3 +177,13 @@
         action->setWhatsThis(text);
     }
 }
+
+void Util::setActionTrashOrDelete(QAction *action, bool isInTrashFolder)
+{
+    if (action) {
+        action->setText(isInTrashFolder ? i18nc("@action Hard delete, bypassing trash", "&Delete") : i18n("&Move to Trash"));
+        action->setIcon(isInTrashFolder ? QIcon::fromTheme(QStringLiteral("edit-delete")) : QIcon::fromTheme(QStringLiteral("user-trash")));
+        //Use same text as in Text property. Change it in kf5
+        action->setToolTip(isInTrashFolder ? i18nc("@action Hard delete, bypassing trash", "Delete") : i18n("Move to Trash"));
+    }
+}