diff --git a/ChangeLog b/ChangeLog
index 9c25b6bcf..d24d4e055 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2012-02-23  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
 
+	* SoObjects/Appointments/SOGoCalendarComponent.m
+	(-sendEMailUsingTemplateNamed:forObject:previousObject:toAttendees:withType:):
+	added a "msgType" parameter that is added as value to the new
+	"x-sogo-message-type" header.
+	(-sendIMIPReplyForEvent:from:to:): added a "x-sogo-message-type"
+	to the headers.
+
 	* OpenChange/MAPIStoreMailContext.m
 	(+listContextForUser:withTDBIndexing:inMemCtx:): make sure special
 	folders have all the "folder" prefixes appended to their list of
diff --git a/SoObjects/Appointments/SOGoAppointmentObject.m b/SoObjects/Appointments/SOGoAppointmentObject.m
index 487d2eca1..640ed92b4 100644
--- a/SoObjects/Appointments/SOGoAppointmentObject.m
+++ b/SoObjects/Appointments/SOGoAppointmentObject.m
@@ -411,9 +411,10 @@
     }
 
   [self sendEMailUsingTemplateNamed: @"Update"
-	forObject: [newEvent itipEntryWithMethod: @"request"]
-	previousObject: oldEvent
-	toAttendees: updateAttendees];
+                          forObject: [newEvent itipEntryWithMethod: @"request"]
+                     previousObject: oldEvent
+                        toAttendees: updateAttendees
+                           withType: @"calendar:invitation-update"];
   [self sendReceiptEmailUsingTemplateNamed: @"Update"
                                  forObject: newEvent to: updateAttendees];
 }
@@ -573,7 +574,8 @@
       [self sendEMailUsingTemplateNamed: @"Deletion"
                               forObject: [newEvent itipEntryWithMethod: @"cancel"]
                          previousObject: oldEvent
-                            toAttendees: attendees];
+                            toAttendees: attendees
+                               withType: @"calendar:cancellation"];
       [self sendReceiptEmailUsingTemplateNamed: @"Deletion"
                                      forObject: newEvent to: attendees];
     }
@@ -627,9 +629,10 @@
 	return ex;
       
       [self sendEMailUsingTemplateNamed: @"Invitation"
-	    forObject: [newEvent itipEntryWithMethod: @"request"]
-	    previousObject: oldEvent
-	    toAttendees: attendees];
+                              forObject: [newEvent itipEntryWithMethod: @"request"]
+                         previousObject: oldEvent
+                            toAttendees: attendees
+                               withType: @"calendar:invitation"];
       [self sendReceiptEmailUsingTemplateNamed: @"Invitation"
                                      forObject: newEvent to: attendees];
     }
@@ -694,7 +697,8 @@
 	  [self sendEMailUsingTemplateNamed: @"Invitation"
 				  forObject: [newEvent itipEntryWithMethod: @"request"]
 			     previousObject: nil
-				toAttendees: attendees];
+				toAttendees: attendees
+                                   withType: @"calendar:invitation"];
           [self sendReceiptEmailUsingTemplateNamed: @"Invitation"
                                          forObject: newEvent to: attendees];
 	}
@@ -1001,7 +1005,8 @@
 	  [self sendEMailUsingTemplateNamed: @"Deletion"
 				  forObject: [event itipEntryWithMethod: @"cancel"]
 			     previousObject: nil
-				toAttendees: delegates];
+				toAttendees: delegates
+                                   withType: @"calendar:cancellation"];
 	  [self sendReceiptEmailUsingTemplateNamed: @"Deletion"
 					 forObject: event
 						to: delegates];
@@ -1022,7 +1027,8 @@
 	  [self sendEMailUsingTemplateNamed: @"Invitation"
 				  forObject: [event itipEntryWithMethod: @"request"]
 			     previousObject: nil
-				toAttendees: delegates];
+				toAttendees: delegates
+                                   withType: @"calendar:invitation"];
 	  [self sendReceiptEmailUsingTemplateNamed: @"Invitation"
 					 forObject: event to: delegates];
 	}
@@ -1335,9 +1341,10 @@
 	  [self _handleRemovedUsers: attendees
 		withRecurrenceId: recurrenceId];
 	  [self sendEMailUsingTemplateNamed: @"Deletion"
-		forObject: [occurence itipEntryWithMethod: @"cancel"]
-		previousObject: nil
-		toAttendees: attendees];
+                                  forObject: [occurence itipEntryWithMethod: @"cancel"]
+                             previousObject: nil
+                                toAttendees: attendees
+                                   withType: @"calendar:cancellation"];
 	  [self sendReceiptEmailUsingTemplateNamed: @"Deletion"
 		forObject: occurence
 		to: attendees];
@@ -1667,9 +1674,10 @@
 		}
 
 	      [self sendEMailUsingTemplateNamed: @"Invitation"
-		    forObject: [event itipEntryWithMethod: @"request"]
-		    previousObject: nil
-		    toAttendees: attendees];
+                                      forObject: [event itipEntryWithMethod: @"request"]
+                                 previousObject: nil
+                                    toAttendees: attendees
+                                       withType: @"calendar:invitation"];
 	      [self sendReceiptEmailUsingTemplateNamed: @"Invitation"
 		    forObject: event to: attendees];
 	    }
diff --git a/SoObjects/Appointments/SOGoCalendarComponent.h b/SoObjects/Appointments/SOGoCalendarComponent.h
index d08389f56..f3c341763 100644
--- a/SoObjects/Appointments/SOGoCalendarComponent.h
+++ b/SoObjects/Appointments/SOGoCalendarComponent.h
@@ -67,7 +67,8 @@
 - (void) sendEMailUsingTemplateNamed: (NSString *) pageName
 			   forObject: (iCalRepeatableEntityObject *) object
 		      previousObject: (iCalRepeatableEntityObject *) previousObject
-                         toAttendees: (NSArray *) attendees;
+                         toAttendees: (NSArray *) attendees
+                            withType: (NSString *) msgType;
 - (void) sendIMIPReplyForEvent: (iCalRepeatableEntityObject *) event
 			  from: (SOGoUser *) from
 			    to: (iCalPerson *) recipient;
diff --git a/SoObjects/Appointments/SOGoCalendarComponent.m b/SoObjects/Appointments/SOGoCalendarComponent.m
index 3be18229c..0b3ed7907 100644
--- a/SoObjects/Appointments/SOGoCalendarComponent.m
+++ b/SoObjects/Appointments/SOGoCalendarComponent.m
@@ -749,6 +749,7 @@ static inline BOOL _occurenceHasID (iCalRepeatableEntityObject *occurence,
 			   forObject: (iCalRepeatableEntityObject *) object
 		      previousObject: (iCalRepeatableEntityObject *) previousObject
                          toAttendees: (NSArray *) attendees
+                            withType: (NSString *) msgType
 {
   NSString *pageName;
   NSString *senderEmail, *shortSenderEmail, *email;
@@ -844,6 +845,8 @@ static inline BOOL _occurenceHasID (iCalRepeatableEntityObject *occurence,
 		  mailDate = [[NSCalendarDate date] rfc822DateString];
 		  [headerMap setObject: mailDate forKey: @"date"];
 		  [headerMap setObject: subject forKey: @"subject"];
+                  if ([msgType length] > 0)
+                    [headerMap setObject: msgType forKey: @"x-sogo-message-type"];
 		  msg = [NGMimeMessage messageWithHeader: headerMap];
 
 		  /* multipart body */
@@ -925,6 +928,7 @@ static inline BOOL _occurenceHasID (iCalRepeatableEntityObject *occurence,
                     forKey: @"subject"];
       [headerMap setObject: @"1.0" forKey: @"MIME-Version"];
       [headerMap setObject: @"multipart/mixed" forKey: @"content-type"];
+      [headerMap setObject: @"calendar:invitation-reply" forKey: @"x-sogo-message-type"];
       msg = [NGMimeMessage messageWithHeader: headerMap];
 
       /* multipart body */