Actually using mail_message.create() bypasses some of the logic contained in message_post. Unless you have some specific needs, you should use message_post instead of directly create a mail_message when trying to create messages and notifications. You can post on a 'void' resource (mail.thread, no thread_id) to create a private conversation or push to some specific partners.

Thanks for the precision. I see that the bypassed logic is for attachments, thread and parent_id. So for simple notifications wouldn't that be ok?

It looks like this code will in fact create an OpenERP message (as visible in Settings > Technical > Messages) but not deliver it to the user. To get it to deliver to the inbox 'subtype_id' needs to be added to the message_data dictionary. For my testing purposes I hardcoded the value as 1 (which is what subtype="mt_comment" evaluated to in my first example)

Ok so it is cleaner to call the message_post method than hardcoding the subtype_id. Unless you really want to get the subtype_id this way:

model_data_obj = self.pool.get('ir.model.data')
ref = model_data_obj.get_object_reference(cr, uid, 'mail', 'mt_comment')

Indeed, the subtype is used to filter the followers of the document that will receive a notification of the message. message_post has an argument subtype that is the xml_id of the subtype; 'mail.mt_comment' is the xml_id of 'Discussions'; we generally use it for user input. In your addon, you may define specific subtypes (mail.message.subtype). Examples of subtypes can be found in crm/crm_lead_data.xml (Stage Changed, Lead Won, ...).

message_post() does not send E-Mails to followers for me even if i do use a subtype?!? What i do: Create a New Lead AND assign a Sales Team: # Create a new Lead (request.registry is deprocated - should use request.env instead) values['section_id'] = request.env.ref('website.salesteam_website_sales').id newlead = request.registry['crm.lead'].create(request.cr, SUPERUSER_ID, values, request.context) Because of the Sales Team there are three Followers for the newly created lead Post a message with message_post() I would expect that all followers of the new lead will receive an e-mail BUT THEY DONT?!? The normal E-Mail (the one for the lead creation is send via E-Mail but messge_post() does not send E-Mails?!? What do i need to do to send E-Mails also when posting a message through code?!? Here is how i call the message_post: leadrecord.message_post(body=recordtext, subject=values['name'], type='email', subtype='mt_lead_create', content_subtype='plaintext') Also tried with: leadrecord.message_post(body=recordtext, subject=values['name'], type='notification', content_subtype='plaintext') Message is posted BUT no E-Mails are send :(