--- a/hgext/notify.py
+++ b/hgext/notify.py
@@ -210,6 +210,8 @@ class notifier(object):
             del msg['From']
             msg['From'] = sender
 
+        msg['Date'] = util.datestr(date=util.makedate(),
+                format="%a, %d %b %Y %H:%M:%S", timezone=True)
         fix_subject()
         fix_sender()