diff --git a/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.h b/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.h
--- a/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.h
+++ b/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.h
@@ -23,7 +23,7 @@
 #include <MimeTreeParser/BodyPart>
 #include <MimeTreeParser/Enums>
 
-#include <KCalCore/MemoryCalendar>
+#include <Akonadi/Calendar/CalendarBase>
 #include <QObject>
 
 namespace MessageViewer
@@ -36,7 +36,7 @@
     MemoryCalendarMemento();
 
     bool finished() const;
-    KCalCore::MemoryCalendar::Ptr calendar() const;
+    Akonadi::CalendarBase::Ptr calendar() const;
 
     void detach() Q_DECL_OVERRIDE;
 
@@ -50,7 +50,7 @@
 
 private:
     bool mFinished;
-    KCalCore::MemoryCalendar::Ptr mCalendar;
+    Akonadi::CalendarBase::Ptr mCalendar;
 };
 
 }
diff --git a/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.cpp b/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.cpp
--- a/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.cpp
+++ b/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.cpp
@@ -64,7 +64,7 @@
     return mFinished;
 }
 
-KCalCore::MemoryCalendar::Ptr MemoryCalendarMemento::calendar() const
+Akonadi::CalendarBase::Ptr MemoryCalendarMemento::calendar() const
 {
     Q_ASSERT(mFinished);
     return mCalendar;
diff --git a/plugins/messageviewer/bodypartformatter/calendar/syncitiphandler.h b/plugins/messageviewer/bodypartformatter/calendar/syncitiphandler.h
--- a/plugins/messageviewer/bodypartformatter/calendar/syncitiphandler.h
+++ b/plugins/messageviewer/bodypartformatter/calendar/syncitiphandler.h
@@ -34,6 +34,7 @@
 
 #include <IncidenceEditor/GroupwareUiDelegate>
 #include <Akonadi/Calendar/ITIPHandler>
+#include <Akonadi/Calendar/CalendarBase>
 
 #include <QObject>
 #include <QEventLoop>
@@ -43,7 +44,8 @@
     Q_OBJECT
 public:
     SyncItipHandler(const QString &receiver, const QString &iCal,
-                    const QString &type, QObject *parent = nullptr);
+                    const QString &type, const Akonadi::CalendarBase::Ptr &calendar,
+                    QObject *parent = nullptr);
 
 public Q_SLOTS:
     void onITipMessageProcessed(Akonadi::ITIPHandler::Result, const QString &errorMessage);
diff --git a/plugins/messageviewer/bodypartformatter/calendar/syncitiphandler.cpp b/plugins/messageviewer/bodypartformatter/calendar/syncitiphandler.cpp
--- a/plugins/messageviewer/bodypartformatter/calendar/syncitiphandler.cpp
+++ b/plugins/messageviewer/bodypartformatter/calendar/syncitiphandler.cpp
@@ -36,22 +36,17 @@
 using namespace Akonadi;
 
 SyncItipHandler::SyncItipHandler(const QString &receiver, const QString &iCal,
-                                 const QString &type, QObject *parent) : QObject(parent)
+                                 const QString &type, const Akonadi::CalendarBase::Ptr &calendar,
+                                 QObject *parent) : QObject(parent)
     , m_result(Akonadi::ITIPHandler::ResultSuccess)
 {
+    Q_ASSERT(calendar);
     Akonadi::ITIPHandler *handler = new Akonadi::ITIPHandler(this);
     QObject::connect(handler, &Akonadi::ITIPHandler::iTipMessageProcessed, this, &SyncItipHandler::onITipMessageProcessed);
 
     m_counterProposalEditorDelegate = new IncidenceEditorNG::GroupwareUiDelegate();
     handler->setGroupwareUiDelegate(m_counterProposalEditorDelegate);
-
-    Akonadi::ETMCalendar::Ptr etmCalendar = CalendarSupport::calendarSingleton(/*createIfNull=*/false);
-    if (etmCalendar && etmCalendar->isLoaded()) {
-        qCDebug(TEXT_CALENDAR_LOG) << "Reusing exising ETM";
-        handler->setCalendar(etmCalendar);
-    } else {
-        qCDebug(TEXT_CALENDAR_LOG) << "Not reusing any ETM";
-    }
+    handler->setCalendar(calendar);
 
     handler->processiTIPMessage(receiver, iCal, type);
 
diff --git a/plugins/messageviewer/bodypartformatter/calendar/text_calendar.cpp b/plugins/messageviewer/bodypartformatter/calendar/text_calendar.cpp
--- a/plugins/messageviewer/bodypartformatter/calendar/text_calendar.cpp
+++ b/plugins/messageviewer/bodypartformatter/calendar/text_calendar.cpp
@@ -714,10 +714,12 @@
         return mailICal(receiver, recv, msg, subject, status, type != Forward, viewerInstance);
     }
 
-    bool saveFile(const QString &receiver, const QString &iCal, const QString &type) const
+    bool saveFile(const QString &receiver, const QString &iCal, const QString &type, MimeTreeParser::Interface::BodyPart *bodyPart) const
     {
+        MemoryCalendarMemento *memento = dynamic_cast<MemoryCalendarMemento *>(bodyPart->memento());
         // This will block. There's no way to make it async without refactoring the memento mechanism
-        SyncItipHandler *itipHandler = new SyncItipHandler(receiver, iCal, type);
+
+        SyncItipHandler *itipHandler = new SyncItipHandler(receiver, iCal, type, memento->calendar());
 
         // If result is ResultCancelled, then we don't show the message box and return false so kmail
         // doesn't delete the e-mail.
@@ -908,7 +910,7 @@
         }
         if (status != Attendee::Delegated) {
             // we do that below for delegated incidences
-            if (!saveFile(receiver, iCal, dir)) {
+            if (!saveFile(receiver, iCal, dir, part)) {
                 return false;
             }
         }
@@ -1009,7 +1011,7 @@
             ICalFormat format;
             format.setTimeSpec(KSystemTimeZones::local());
             const QString iCal = format.createScheduleMessage(incidence, iTIPRequest);
-            if (!saveFile(receiver, iCal, dir)) {
+            if (!saveFile(receiver, iCal, dir, part)) {
                 return false;
             }
 
@@ -1106,6 +1108,8 @@
         // FIXME: this function should be inside a QObject, and async,
         //         and Q_EMIT a signal when korg registered itself successfuly
 
+        // Or better, use DBus activation in all cases.
+
         QString error;
         bool result = true;
         QString dbusService;
@@ -1242,7 +1246,7 @@
 
         // Don't delete the invitation here in any case, if the counter proposal
         // is declined you might need it again.
-        return saveFile(receiver, iCal, QStringLiteral("counter"));
+        return saveFile(receiver, iCal, QStringLiteral("counter"), part);
     }
 
     bool handleClick(Viewer *viewerInstance,
@@ -1324,7 +1328,7 @@
         } else if (path == QLatin1String("reply") || path == QLatin1String("cancel") || path == QLatin1String("accept_counter")) {
             // These should just be saved with their type as the dir
             const QString p = (path == QLatin1String("accept_counter") ? QStringLiteral("reply") : path);
-            if (saveFile(QStringLiteral("Receiver Not Searched"), iCal, p)) {
+            if (saveFile(QStringLiteral("Receiver Not Searched"), iCal, p, part)) {
                 if (MessageViewer::MessageViewerSettings::self()->deleteInvitationEmailsAfterSendingReply()) {
                     viewerInstance->deleteMessage();
                 }
@@ -1364,7 +1368,7 @@
             }
             //fall through
             case KMessageBox::Yes: // means "do not send"
-                if (saveFile(QStringLiteral("Receiver Not Searched"), iCal, QStringLiteral("reply"))) {
+                if (saveFile(QStringLiteral("Receiver Not Searched"), iCal, QStringLiteral("reply"), part)) {
                     if (MessageViewer::MessageViewerSettings::self()->deleteInvitationEmailsAfterSendingReply()) {
                         viewerInstance->deleteMessage();
                         result = true;