diff --git a/ActiveSync/SOGoActiveSyncDispatcher.m b/ActiveSync/SOGoActiveSyncDispatcher.m
index e9264283d..5bbc394c9 100644
--- a/ActiveSync/SOGoActiveSyncDispatcher.m
+++ b/ActiveSync/SOGoActiveSyncDispatcher.m
@@ -2490,6 +2490,9 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
       else
         [map setObject: email forKey: @"from"];
 
+      if ([[mailObject envelope] messageId])
+        [map setObject: [[mailObject envelope] messageId] forKey: @"in-reply-to"];
+
       messageToSend = [[[NGMimeMessage alloc] initWithHeader: map] autorelease];
       body = [[[NGMimeMultipartBody alloc] initWithPart: messageToSend] autorelease];
       
diff --git a/ActiveSync/SOGoMailObject+ActiveSync.m b/ActiveSync/SOGoMailObject+ActiveSync.m
index 3e513a4d5..96f05e929 100644
--- a/ActiveSync/SOGoMailObject+ActiveSync.m
+++ b/ActiveSync/SOGoMailObject+ActiveSync.m
@@ -973,9 +973,18 @@ struct GlobalObjectId {
       [s appendFormat: @"</Categories>"];
     }
   
+  if ([[[context request] headerForKey: @"MS-ASProtocolVersion"] isEqualToString: @"14.0"] &&
+      [[[context request] headerForKey: @"MS-ASProtocolVersion"] isEqualToString: @"14.1"])
+    {
+      if ([self inReplyTo])
+        [s appendFormat: @"<ConversationId xmlns=\"Email2:\">%@</ConversationId>", [[[self inReplyTo] dataUsingEncoding: NSUTF8StringEncoding] activeSyncRepresentationInContext: context]];
+      else if ([self messageId])
+        [s appendFormat: @"<ConversationId xmlns=\"Email2:\">%@</ConversationId>", [[[self messageId] dataUsingEncoding: NSUTF8StringEncoding] activeSyncRepresentationInContext: context]];
+    }
+
   // FIXME - support these in the future
-  //[s appendString: @"<ConversationId xmlns=\"Email2:\">foobar</ConversationId>"];
   //[s appendString: @"<ConversationIndex xmlns=\"Email2:\">zot=</ConversationIndex>"];
+
   
   // NativeBodyType -- http://msdn.microsoft.com/en-us/library/ee218276(v=exchg.80).aspx
   // This is a required child element.