[Zope] "To: undisclosed recipient;:" when sending mail through a script !!!

Hi, My app sends mail through a python script like this... body = "blah blah body" title = "blah blah title" mh = container.mailhost_list()[0] mh.send(body, mto='me@somedomain.com', mfrom='mailmaster@somedomain.com', subject=title, encoding='quoted-printable') return 'OK' This works but the mail has not the excepted "to" header and shows... "To: undisclosed-recipients: ;" This is pretty unfair in the mail client. Did I miss something to have the "mto" parameter of the .send() method in the "To:" header of the mail ? Thanks in advance --Gilles