diff --git a/addons/base_calendar/base_calendar.py b/addons/base_calendar/base_calendar.py
index bf93c9c775d..8a9764bff63 100644
--- a/addons/base_calendar/base_calendar.py
+++ b/addons/base_calendar/base_calendar.py
@@ -410,7 +410,10 @@ property or property parameter."),
             event.add('location').value = event_obj.location
         if event_obj.rrule:
             event.add('rrule').value = event_obj.rrule
-
+        if event_obj.user_id:
+            event_org = event.add('organizer')
+            event_org.params['CN'] = [event_obj.user_id.name]
+            event_org.value = 'MAILTO:' + (event_obj.user_id.user_email or event_obj.user_id.name)
         if event_obj.alarm_id:
             # computes alarm data
             valarm = event.add('valarm')
@@ -440,7 +443,7 @@ property or property parameter."),
             attendee_add.params['CUTYPE'] = [str(attendee.cutype)]
             attendee_add.params['ROLE'] = [str(attendee.role)]
             attendee_add.params['RSVP'] = [str(attendee.rsvp)]
-            attendee_add.value = 'MAILTO:' + attendee.email
+            attendee_add.value = 'MAILTO:' + (attendee.email or '')
         res = cal.serialize()
         return res
     
@@ -480,8 +483,8 @@ property or property parameter."),
                         'company': company
             }
             body = html_invitation % body_vals
-            attach = self.get_ics_file(cr, uid, res_obj, context=context)
             if mail_to and email_from:
+                attach = self.get_ics_file(cr, uid, res_obj, context=context)
                 tools.email_send(
                     email_from, 
                     mail_to,