[NEW] mail_prevent_send_note_to_external

mail_prevent_send_note_to_external/models/__init__.py

@@ -0,0 +1 @@
+from . import mail_thread

mail_prevent_send_note_to_external/models/mail_thread.py

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+from odoo import api, models, _
+
+
+class MailThread(models.AbstractModel):
+    _inherit = 'mail.thread'
+
+    @api.returns('mail.message', lambda value: value.id)
+    def message_post(self, **kwargs):    
+        #check subtype_xmlid and partner_ids, and remove external partners if subtype is "note"
+        if kwargs.get("subtype_xmlid") == 'mail.mt_note' and "partner_ids" in kwargs:
+            new_partner_ids = []
+            for partner_id in kwargs["partner_ids"]:
+                user = self.env["res.users"].search([('partner_id','=',partner_id)])
+                if user.active and user.has_group('base.group_user'):
+                    new_partner_ids.append(partner_id)
+            kwargs["partner_ids"] = new_partner_ids
+
+        message = super(MailThread, self).message_post(**kwargs)
+        return message