[mq]: validation_from_empty_value

views/email.py

@@ -34,7 +34,7 @@
     # sender address has been removed, look in email's headers
     message = email.umessage_headers()
     if message:
-        return xml_escape(message.get('From'))
+        return xml_escape(message.get('From', ''))
     return email._cw._('unknown sender')
 
 class EmailPrimaryView(primary.PrimaryView):