make it possible to add extra email headers

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@15894 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/Url.py

@@ -142,7 +142,7 @@ class Url(Coordinate, Base, UrlMixIn):
 
   security.declareProtected(Permissions.UseMailhostServices, 'send')
   def send(self, from_url=None, to_url=None, msg=None,
-           subject=None,  attachment_list=None):
+           subject=None, attachment_list=None, extra_headers=None):
     """
     This method was previously named 'SendMail' and is used to send email
 
@@ -150,6 +150,8 @@ class Url(Coordinate, Base, UrlMixIn):
      - name : name of the attachment,
      - content: data of the attachment
      - mime_type: mime-type corresponding to the attachment
+    * extra_headers is a dictionnary of custom headers to add to the email.
+      "X-" prefix is automatically added to those headers.
     """
     # get the mailhost object
     mailhost = getattr(self.getPortalObject(), 'MailHost', None)
@@ -174,6 +176,10 @@ class Url(Coordinate, Base, UrlMixIn):
                            "can not handle multi-part messages!\n"
         message.attach(MIMEText(msg, _charset='utf-8'))
       
+      if extra_headers:
+        for k, v in extra_headers.items():
+          message.add_header('X-%s' % k, v)
+
       message.add_header('Subject',
                          make_header([(subject, 'utf-8')]).encode())
       message.add_header('From', from_url)