diff --git a/addons/mail/models/mail_thread.py b/addons/mail/models/mail_thread.py
index 82309efe62d..b36a866ca5f 100644
--- a/addons/mail/models/mail_thread.py
+++ b/addons/mail/models/mail_thread.py
@@ -2287,7 +2287,8 @@ class MailThread(models.AbstractModel):
             'mail_message_id': message.id,
             'mail_server_id': message.mail_server_id.id, # 2 query, check acces + read, may be useless, Falsy, when will it be used?
             'auto_delete': mail_auto_delete,
-            'references': message.parent_id.message_id if message.parent_id else False,
+            # due to ir.rule, user have no right to access parent message if message is not published
+            'references': message.parent_id.sudo().message_id if message.parent_id else False,
             'subject': mail_subject,
         }
         headers = self._notify_email_headers()
diff --git a/addons/test_mail/tests/test_mail_message.py b/addons/test_mail/tests/test_mail_message.py
index 2ff5c6f7d5f..1487597f56a 100644
--- a/addons/test_mail/tests/test_mail_message.py
+++ b/addons/test_mail/tests/test_mail_message.py
@@ -2,9 +2,11 @@
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
 import base64
+from unittest.mock import patch
 
 from odoo.addons.mail.tests.common import mail_new_test_user
 from odoo.addons.test_mail.tests.common import TestMailCommon
+from odoo.addons.test_mail.models.test_mail_models import MailTestSimple
 from odoo.exceptions import AccessError, except_orm
 from odoo.tools import mute_logger, formataddr
 from odoo.tests import tagged
@@ -322,6 +324,45 @@ class TestMessageAccess(TestMailCommon):
         self.message.write({'partner_ids': [(4, self.user_employee.partner_id.id)]})
         self.env['mail.message'].with_user(self.user_employee).create({'model': 'mail.channel', 'res_id': self.group_private.id, 'body': 'Test', 'parent_id': self.message.id})
 
+    def test_mail_message_access_create_wo_parent_access(self):
+        """ Purpose is to test posting a message on a record whose first message / parent
+        is not accessible by current user. """
+        test_record = self.env['mail.test.simple'].with_context(self._test_context).create({'name': 'Test', 'email_from': 'ignasse@example.com'})
+        partner_1 = self.env['res.partner'].create({
+            'name': 'Jitendra Prajapati (jpr-odoo)',
+            'email': 'jpr@odoo.com',
+        })
+        test_record.message_subscribe((partner_1 | self.user_admin.partner_id).ids)
+
+        message = test_record.message_post(
+            body='<p>This is First Message</p>', subject='Subject',
+            message_type='comment', subtype_xmlid='mail.mt_note')
+        # portal user have no rights to read the message
+        with self.assertRaises(except_orm):
+            message.with_user(self.user_portal).read(['subject, body'])
+
+        with patch.object(MailTestSimple, 'check_access_rights', return_value=True):
+            with self.assertRaises(except_orm):
+                message.with_user(self.user_portal).read(['subject, body'])
+
+            # parent message is accessible to references notification mail values
+            # for _notify method and portal user have no rights to send the message for this model
+            new_msg = test_record.with_user(self.user_portal).message_post(
+                body='<p>This is Second Message</p>',
+                subject='Subject',
+                parent_id=message.id,
+                message_type='comment',
+                subtype_xmlid='mail.mt_comment',
+                mail_auto_delete=False)
+
+        new_mail = self.env['mail.mail'].sudo().search([
+            ('mail_message_id', '=', new_msg.id),
+            ('references', '=', message.message_id),
+        ])
+
+        self.assertTrue(new_mail)
+        self.assertEqual(new_msg.parent_id, message)
+
     # --------------------------------------------------
     # WRITE
     # --------------------------------------------------