diff --git a/CMakeLists.txt b/CMakeLists.txt
index 54ada3525..ac7d2ff32 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -226,6 +226,7 @@ set(kmailprivate_LIB_SRCS
    scalix.cpp
    messageactions.cpp
    statusbarlabel.cpp
+   groupware_types.cpp
 )
 
 qt4_add_dbus_adaptor( kmailprivate_LIB_SRCS ${CMAKE_BINARY_DIR}/kmail/org.kde.kmail.kmail.xml kmkernel.h KMKernel )
diff --git a/groupware_types.cpp b/groupware_types.cpp
new file mode 100644
index 000000000..ff95eeb22
--- /dev/null
+++ b/groupware_types.cpp
@@ -0,0 +1,81 @@
+/*
+    Copyright (c) 2007 Montel Laurent <montel@kde.org>
+    Copyright (c) 2008 Volker Krause <vkrause@kde.org>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+*/
+
+#include "groupware_types.h"
+
+#include <QDBusArgument>
+#include <QDBusMetaType>
+
+const QDBusArgument &operator<<(QDBusArgument &arg, const KMail::SubResource &subResource)
+{
+  arg.beginStructure();
+  arg << subResource.location << subResource.label << subResource.writable << subResource.alarmRelevant;
+  arg.endStructure();
+  return arg;
+}
+
+const QDBusArgument &operator>>(const QDBusArgument &arg, KMail::SubResource &subResource)
+{
+  arg.beginStructure();
+  arg >> subResource.location >> subResource.label >> subResource.writable >> subResource.alarmRelevant;
+  arg.endStructure();
+  return arg;
+}
+
+const QDBusArgument &operator<<(QDBusArgument &arg, const KMail::StorageFormat &format)
+{
+  arg.beginStructure();
+  qint32 i = format;
+  arg << i;
+  arg.endStructure();
+  return arg;
+}
+
+const QDBusArgument &operator>>(const QDBusArgument &arg, KMail::StorageFormat &format)
+{
+  arg.beginStructure();
+  arg >> format;
+  arg.endStructure();
+  return arg;
+}
+
+const QDBusArgument &operator<<( QDBusArgument &arg, const KMail::CustomHeader &header )
+{
+  arg.beginStructure();
+  arg << header.name << header.value;
+  arg.endStructure();
+  return arg;
+}
+
+const QDBusArgument &operator>>( const QDBusArgument &arg, KMail::CustomHeader &header )
+{
+  arg.beginStructure();
+  arg >> header.name >> header.value;
+  arg.endStructure();
+  return arg;
+}
+
+void KMail::registerGroupwareTypes()
+{
+  qDBusRegisterMetaType< KMail::SubResource >();
+  qDBusRegisterMetaType< KMail::SubResource::List >();
+  qDBusRegisterMetaType< QMap<quint32,QString> >();
+  qDBusRegisterMetaType< KMail::CustomHeader >();
+  qDBusRegisterMetaType< KMail::CustomHeader::List >();
+}
diff --git a/kmail_util.h b/groupware_types.h
similarity index 76%
rename from kmail_util.h
rename to groupware_types.h
index 70ebf182d..125af2caf 100644
--- a/kmail_util.h
+++ b/groupware_types.h
@@ -27,12 +27,16 @@
  *  you do not wish to do so, delete this exception statement from
  *  your version.
  */
-#ifndef KMAILUTILS_H
-#define KMAILUTILS_H
+
+#ifndef KMAIL_GROUPWARETYPES_H
+#define KMAIL_GROUPWARETYPES_H
 
 #include <QMetaType>
 
-#define DBUS_KMAIL "org.kde.kmail"
+#define KMAIL_DBUS_SERVICE "org.kde.kmail"
+#define KMAIL_DBUS_GROUPWARE_PATH "/Groupware"
+#define KMAIL_DBUS_GROUPWARE_INTERFACE "org.kde.kmail.groupware"
+
 namespace KMail {
 
   struct SubResource {
@@ -46,6 +50,8 @@ namespace KMail {
     QString label;    // shown to the user
     bool writable;
     bool alarmRelevant;
+
+    typedef QList<SubResource> List;
   };
 
   /// The format of the mails containing other contents than actual mail
@@ -57,14 +63,33 @@ namespace KMail {
 
   /// This bitfield indicates which changes have been made in a folder, at syncing time.
   enum FolderChanges { NoChange = 0, ContentsChanged = 1, ACLChanged = 2 };
+
+  /** Custom header structure, consisting of the header name and value. */
+  struct CustomHeader
+  {
+    CustomHeader() {}
+    CustomHeader( const QByteArray &n, const QString &v ) :
+        name( n ), value( v ) {}
+
+    QByteArray name;
+    QString value;
+
+    typedef QList<CustomHeader> List;
+  };
+
+  /**
+    Register D-Bus types.
+  */
+  void registerGroupwareTypes();
 }
 
+typedef QMap<quint32, QString> Quint32QStringMap;
+
 Q_DECLARE_METATYPE( KMail::SubResource )
-Q_DECLARE_METATYPE( QList<KMail::SubResource> )
+Q_DECLARE_METATYPE( KMail::SubResource::List )
 Q_DECLARE_METATYPE( KMail::StorageFormat )
-typedef QMap<quint32, QString> Quint32QStringMap;
 Q_DECLARE_METATYPE( Quint32QStringMap )
-typedef QMap<QByteArray, QString> QByteArrayStringMap;
-Q_DECLARE_METATYPE( QByteArrayStringMap)
+Q_DECLARE_METATYPE( KMail::CustomHeader )
+Q_DECLARE_METATYPE( KMail::CustomHeader::List )
 
 #endif
diff --git a/kmailicalifaceimpl.cpp b/kmailicalifaceimpl.cpp
index a56cad555..02061c1ed 100644
--- a/kmailicalifaceimpl.cpp
+++ b/kmailicalifaceimpl.cpp
@@ -140,6 +140,7 @@ ExtraFolder::~ExtraFolder()
         folder->close("kmailicaliface::extrafolder");
 }
 
+#if 0
 const QDBusArgument &operator<<(QDBusArgument &arg, const SubResource &subResource)
 {
   arg.beginStructure();
@@ -173,6 +174,7 @@ const QDBusArgument &operator>>(const QDBusArgument &arg, StorageFormat &format)
   arg.endStructure();
   return arg;
 }
+#endif
 
 
 /*
@@ -208,8 +210,9 @@ KMailICalIfaceImpl::~KMailICalIfaceImpl()
 
 void KMailICalIfaceImpl::registerWithDBus()
 {
-  qDBusRegisterMetaType< QList<KMail::SubResource> >();
-  qDBusRegisterMetaType< QMap<quint32,QString> >();
+/*  qDBusRegisterMetaType< QList<KMail::SubResource> >();
+  qDBusRegisterMetaType< QMap<quint32,QString> >();*/
+  KMail::registerGroupwareTypes();
   QDBusConnection::sessionBus().registerObject( "/Groupware", this, QDBusConnection::ExportAdaptors );
   new GroupwareAdaptor( this );
 }
@@ -449,7 +452,7 @@ static void setXMLContentTypeHeader( KMMessage *msg, const QString &plainTextBod
 quint32 KMailICalIfaceImpl::addIncidenceKolab( KMFolder& folder,
                                                 const QString& subject,
                                                 const QString& plainTextBody,
-                                                const QMap<QByteArray, QString>& customHeaders,
+                                                const KMail::CustomHeader::List& customHeaders,
                                                 const QStringList& attachmentURLs,
                                                 const QStringList& attachmentNames,
                                                 const QStringList& attachmentMimetypes )
@@ -465,11 +468,8 @@ quint32 KMailICalIfaceImpl::addIncidenceKolab( KMFolder& folder,
   msg->setSubject( subject );
   msg->setAutomaticFields( true );
 
-  QMap<QByteArray, QString>::ConstIterator ith = customHeaders.begin();
-  const QMap<QByteArray, QString>::ConstIterator ithEnd = customHeaders.end();
-  for ( ; ith != ithEnd ; ++ith ) {
-    msg->setHeaderField( ith.key(), ith.value() );
-  }
+  foreach ( const CustomHeader header, customHeaders )
+    msg->setHeaderField( header.name, header.value );
   // In case of the ical format, simply add the plain text content with the
   // right content type
   if ( storageFormat( &folder ) == StorageXML ) {
@@ -813,7 +813,7 @@ quint32 KMailICalIfaceImpl::update( const QString& resource,
                                      quint32 sernum,
                                      const QString& subject,
                                      const QString& plainTextBody,
-                                     const QMap<QByteArray, QString>& customHeaders,
+                                     const KMail::CustomHeader::List& customHeaders,
                                      const QStringList& attachmentURLs,
                                      const QStringList& attachmentMimetypes,
                                      const QStringList& attachmentNames,
@@ -848,10 +848,8 @@ quint32 KMailICalIfaceImpl::update( const QString& resource,
     // Message found - make a copy and update it:
     KMMessage* newMsg = new KMMessage( *msg );
     newMsg->setSubject( subject );
-    QMap<QByteArray, QString>::ConstIterator ith = customHeaders.begin();
-    const QMap<QByteArray, QString>::ConstIterator ithEnd = customHeaders.begin();
-    for ( ; ith != ithEnd ; ++ith )
-      newMsg->setHeaderField( ith.key(), ith.value() );
+    foreach ( const CustomHeader header, customHeaders )
+      newMsg->setHeaderField( header.name, header.value );
     newMsg->setParent( 0 ); // workaround strange line in KMMsgBase::assign. newMsg is not in any folder yet.
     // Note that plainTextBody isn't used in this branch. We assume it's still valid from when the mail was created.
 
diff --git a/kmailicalifaceimpl.h b/kmailicalifaceimpl.h
index ca4716bfc..e13c4b2c5 100644
--- a/kmailicalifaceimpl.h
+++ b/kmailicalifaceimpl.h
@@ -48,7 +48,7 @@
 #include <kfoldertree.h>
 using KPIM::KFolderTreeItem;
 #include "kmfoldertype.h"
-#include "kmail_util.h"
+#include "groupware_types.h"
 
 class KMFolder;
 class KMMessage;
@@ -113,7 +113,7 @@ public:
                    quint32 sernum,
                    const QString& subject,
                    const QString& plainTextBody,
-                   const QMap<QByteArray, QString>& customHeaders,
+                   const KMail::CustomHeader::List& customHeaders,
                    const QStringList& attachmentURLs,
                    const QStringList& attachmentMimetypes,
                    const QStringList& attachmentNames,
@@ -299,7 +299,7 @@ private:
   quint32 addIncidenceKolab( KMFolder& folder,
                               const QString& subject,
                               const QString& plainTextBody,
-                              const QMap<QByteArray, QString>& customHeaders,
+                              const KMail::CustomHeader::List& customHeaders,
                               const QStringList& attachmentURLs,
                               const QStringList& attachmentNames,
                               const QStringList& attachmentMimetypes );
diff --git a/kmkernel.cpp b/kmkernel.cpp
index 6bed70ed7..8e1e48cee 100644
--- a/kmkernel.cpp
+++ b/kmkernel.cpp
@@ -85,7 +85,7 @@ using KWallet::Wallet;
 #include "kmailinterface.h"
 
 #include "folderadaptor.h"
-#include "kmail_util.h"
+#include "groupware_types.h"
 
 static KMKernel * mySelf = 0;
 
@@ -992,7 +992,7 @@ QString KMKernel::getFolder( const QString& vpath )
 
 void KMKernel::raise()
 {
-  QDBusInterface iface( DBUS_KMAIL, "/MainApplication",
+  QDBusInterface iface( KMAIL_DBUS_SERVICE, "/MainApplication",
                         "org.kde.KUniqueApplication",
                         QDBusConnection::sessionBus());
   QDBusReply<int> reply;
@@ -1458,7 +1458,7 @@ void KMKernel::cleanupImapFolders()
   {
     KMFolderNode *node = *it;
     if (node->isDir() || ((acct = the_acctMgr->find(node->id()))
-                          && ( acct->type() == KAccount::Imap )) 
+                          && ( acct->type() == KAccount::Imap ))
                       || !the_acctMgr->isEnabled( node->id() ))
     {
       ++it;
diff --git a/org.kde.kmail.groupware.xml b/org.kde.kmail.groupware.xml
index bb3768750..affd18c75 100644
--- a/org.kde.kmail.groupware.xml
+++ b/org.kde.kmail.groupware.xml
@@ -55,7 +55,6 @@
     </method>
     <method name="storageFormat">
       <arg name="resource" type="s" direction="in"/>
-      <!-- ### Shouldn't that be just 'i'? -->
       <arg type="(i)" direction="out"/>
       <annotation name="com.trolltech.QtDBus.QtTypeName.Out0" value="KMail::StorageFormat"/>
     </method>
@@ -76,13 +75,12 @@
       <arg name="sernum" type="u" direction="in"/>
       <arg name="subject" type="s" direction="in"/>
       <arg name="plainTextBody" type="s" direction="in"/>
-      <!-- FIXME should be a{ays} but qdbusxml2cpp considers that invalid -->
-      <arg name="customHeaders" type="a{ss}" direction="in"/>
+      <arg name="customHeaders" type="a(ays)" direction="in"/>
       <arg name="attachmentURLs" type="as" direction="in"/>
       <arg name="attachmentMimetypes" type="as" direction="in"/>
       <arg name="attachmentNames" type="as" direction="in"/>
       <arg name="deletedAttachments" type="as" direction="in"/>
-      <annotation name="com.trolltech.QtDBus.QtTypeName.In4" value="const QMap&lt;QByteArray, QString&gt; &amp;"/>
+      <annotation name="com.trolltech.QtDBus.QtTypeName.In4" value="const QList&lt;KMail::CustomHeader&gt; &amp;"/>
     </method>
     <method name="incidencesKolab">
       <arg type="a{us}" direction="out"/>
@@ -95,7 +93,7 @@
     <method name="subresourcesKolab">
       <arg type="a(ssbb)" direction="out"/>
       <arg name="contentsType" type="s" direction="in"/>
-      <annotation name="com.trolltech.QtDBus.QtTypeName.Out0" value="QList&lt;KMail::SubResource&gt;"/>
+      <annotation name="com.trolltech.QtDBus.QtTypeName.Out0" value="KMail::SubResource::List"/>
     </method>
   </interface>
 </node>
diff --git a/tests/dbustest.cpp b/tests/dbustest.cpp
index 490711486..c486d0d82 100644
--- a/tests/dbustest.cpp
+++ b/tests/dbustest.cpp
@@ -3,8 +3,8 @@
 #include <kdebug.h>
 #include <kapplication.h>
 #include <kcmdlineargs.h>
-#include <kmail_util.h>
 
+#include "groupware_types.h"
 #include "kmailinterface.h"
 #include "mailcomposerinterface.h"
 #include "aboutdata.h"
@@ -21,7 +21,7 @@ int main(int argc,char **argv)
   KCmdLineArgs::init(argc, argv, &aboutData);
   KApplication app;
 
-  OrgKdeKmailKmailInterface kmailInterface( DBUS_KMAIL, "/KMail", QDBusConnection::sessionBus());
+  OrgKdeKmailKmailInterface kmailInterface( KMAIL_DBUS_SERVICE, "/KMail", QDBusConnection::sessionBus());
   kmailInterface.openComposer( "to 1","","","First test","simple openComp call",0);
 
   QDBusReply<QDBusObjectPath> composerDbusPath =  kmailInterface.openComposer("to 2","","","Second test",  "DBUS ref call",0);
@@ -34,7 +34,7 @@ int main(int argc,char **argv)
 
   QDBusObjectPath composerPath = composerDbusPath;
   kDebug()<<"composerPath :"<<composerPath.path();
-  OrgKdeKmailMailcomposerInterface kmailComposerInterface( DBUS_KMAIL, composerPath.path(),  QDBusConnection::sessionBus());
+  OrgKdeKmailMailcomposerInterface kmailComposerInterface( KMAIL_DBUS_SERVICE, composerPath.path(),  QDBusConnection::sessionBus());
 
   QByteArray data = "BEGIN:VCALENDAR\nEND:VCALENDAR";
   kmailComposerInterface.addAttachment("test.ics","7bit",data,"text","calendar","method",