Support arbitrary email headers

As discussed in  nexedi/erp5!248 this approach allows to set any mail header.

I also included a not so related patch of email header handlings 88d40b40 so that we review all this together.

/cc @gabriel @kazuhiko 

/reviewed-on nexedi/erp5!256

bt5/erp5_base/SkinTemplateItem/portal_skins/erp5_base/Base_createMailMessageAsString.py

+"""Build a mail message
+
+ * from_url: the "from" address as UTF-8 encoded string
+ * to_url: the "to" header as UTF-8 encoded string
+ * subject: the subject of the message as UTF-8 encoded string
+ * body: body of the message as UTF-8 encoded string
+ * content_type: mime type of this message, can be text/html for
+   HTML message or anything else for text/plain message.
+ * attachment_list: a list of attachement mapping in format:
+    - mime_type: mime type of thsi attachement
+    - content: file content of the attachement, as a string
+    - name: displayed name of this attachements
+ * embedded_file_list: a list of ERP5 File to use as attachments.
+ * extra_header_dict: additional email headers
+
+Notes: for from_url and to_url, we should use email.utils.formataddr
+"""
+if extra_header_dict is None:
+  extra_header_dict = {}
+
 if content_type == 'text/html':
   mail_template = context.Event_viewHtmlMimeMessage
 else:
@@ -20,7 +40,8 @@ multipart = mail_template.as_message(mfrom=from_url,
                                      mto=to_url,
                                      subject=subject,
                                      body=body,
-                                     encoding='utf-8')
+                                     encoding='utf-8',
+                                     headers=extra_header_dict)
 for attachment_dict in attachment_list:
   multipart.add_file(data=attachment_dict['content'],
                      content_type=attachment_dict['mime_type'],

bt5/erp5_base/SkinTemplateItem/portal_skins/erp5_base/Base_createMailMessageAsString.xml

@@ -50,7 +50,7 @@
         </item>
         <item>
             <key> <string>_params</string> </key>
-            <value> <string>from_url, to_url, subject, body, content_type, attachment_list=[], embedded_file_list=[]</string> </value>
+            <value> <string>from_url, to_url, subject, body, content_type, attachment_list=[], embedded_file_list=[], extra_header_dict=None</string> </value>
         </item>
         <item>
             <key> <string>id</string> </key>

bt5/erp5_base/SkinTemplateItem/portal_skins/erp5_base/Entity_sendEmail.py

@@ -17,12 +17,16 @@ to_url = formataddr((context.hasTitle() and context.getTitle(), context.getDefau
 document_type_list = list(event.getPortalEmbeddedDocumentTypeList()) + list(event.getPortalDocumentTypeList())
 embedded_file_list = event.getAggregateValueList(portal_type=document_type_list)
 
+extra_header_dict = kw.get('extra_header_dict') or {}
+
 content_type = event.getContentType()
-mail_message = portal.Base_createMailMessageAsString(from_url,
+mail_message = portal.Base_createMailMessageAsString(
+  from_url,
   to_url,
   subject,
   body,
   content_type,
-  embedded_file_list=embedded_file_list)
+  embedded_file_list=embedded_file_list,
+  extra_header_dict=extra_header_dict)
 
 event.sendMailHostMessage(mail_message)

bt5/erp5_base/SkinTemplateItem/portal_skins/erp5_base/MailMessage_send.py

@@ -70,12 +70,14 @@ if download or not use_activity:
 
     content_type = context.getContentType()
 
-    mail_message = context.Base_createMailMessageAsString(from_url, 
+    mail_message = context.Base_createMailMessageAsString(
+      from_url,
       to_url,
       subject,
       body,
       content_type,
-      embedded_file_list=embedded_file_list)
+      embedded_file_list=embedded_file_list,
+      extra_header_dict=extra_header_dict)
 
     if not use_activity:
       context.activate(activity='SQLQueue').sendMailHostMessage(mail_message)
@@ -83,6 +85,8 @@ if download or not use_activity:
 if use_activity:
   method_kw = dict(event_relative_url=context.getRelativeUrl(),
                    from_url=from_url)
+  if extra_header_dict:
+    method_kw['extra_header_dict'] = extra_header_dict
   context.activate(
     after_path_and_method_id=((context.getPath(),), 
                               ('immediateReindexObject', 'recursiveImmediateReindexObject'))).MailMessage_sendByActivity(

bt5/erp5_base/SkinTemplateItem/portal_skins/erp5_base/MailMessage_send.xml

@@ -50,7 +50,7 @@
         </item>
         <item>
             <key> <string>_params</string> </key>
-            <value> <string>from_url=None, to_url=None, reply_url=None, subject=None, body=None, attachment_format=None, attachment_list=None, download=None, **kw</string> </value>
+            <value> <string>from_url=None, to_url=None, reply_url=None, subject=None, body=None, attachment_format=None, attachment_list=None, download=None, extra_header_dict=None, **kw</string> </value>
         </item>
         <item>
             <key> <string>_proxy_roles</string> </key>

product/ERP5/Tool/NotificationTool.py

@@ -40,6 +40,7 @@ from email.mime.text import MIMEText
 from email.mime.base import MIMEBase
 from email.mime.audio import MIMEAudio
 from email.mime.image import MIMEImage
+from email.utils import formataddr
 from email.header import make_header
 from email import encoders
 
@@ -333,8 +334,7 @@ class NotificationTool(BaseTool):
     default_from_name = getattr(portal, 'email_from_name', default_from_name)
     if from_person is None:
       # when sending without sender defined compose identifiable From header
-      low_level_kw['from_url'] = '%s <%s>' % (default_from_name,
-          default_from_email)
+      low_level_kw['from_url'] = formataddr((default_from_name, default_from_email))
     if not to_person_list:
       low_level_kw['to_url'] = default_to_email
     if attachment_list is not None:

product/ERP5/tests/testCRM.py

@@ -1852,6 +1852,20 @@ class TestCRMMailSend(BaseTestCRM):
     self.assertEqual('FG ER <eee@eee.com>', from_url)
     self.assertEqual(['Expert User <expert@in24.test>'], to_url)
 
+  def test_MailMessage_send_extra_headers(self):
+    """Test sending message with extra headers
+    """
+    mail_message = self.portal.event_module.newContent(
+        portal_type="Mail Message",
+        source='person_module/me',
+        destination='person_module/recipient')
+
+    mail_message.send(extra_header_dict={"X-test-header": "test"})
+    self.tic()
+    (from_url, to_url, last_message,), = self.portal.MailHost._message_list
+    message = message_from_string(last_message)
+    self.assertEqual("test", message.get("X-test-header"))
+
 
 def test_suite():
   suite = unittest.TestSuite()