diff --git a/addons/event/event.py b/addons/event/event.py
index 42ed73fc055..ab4b6e8f9fa 100644
--- a/addons/event/event.py
+++ b/addons/event/event.py
@@ -331,7 +331,11 @@ class event_registration(models.Model):
             body=_('New registration confirmed: %s.') % (self.name or ''),
             subtype="event.mt_event_registration")
         self.state = 'open'
-        self.env['event.mail'].run()
+
+        # auto-trigger after_sub (on subscribe) mail schedulers, if needed
+        onsubscribe_schedulers = self.event_id.event_mail_ids.filtered(
+            lambda s: s.interval_type == 'after_sub')
+        onsubscribe_schedulers.execute()
 
     @api.one
     def button_reg_close(self):
diff --git a/addons/event/tests/test_mail_schedule.py b/addons/event/tests/test_mail_schedule.py
index c712e48919f..f92cf0fcc5b 100644
--- a/addons/event/tests/test_mail_schedule.py
+++ b/addons/event/tests/test_mail_schedule.py
@@ -48,27 +48,12 @@ class TestMailSchedule(TestEventCommon):
             'email': 'reg1@example.com',
         })
 
-        # check before event scheduler
-        schedulers = self.EventMail.search([('event_id', '=', test_event.id), ('interval_type', '=', 'before_event')])
-        self.assertEqual(len(schedulers), 1, 'event: wrong scheduler creation')
-        self.assertEqual(schedulers[0].scheduled_date, datetime.datetime.strftime(event_date_begin + relativedelta(days=-2), tools.DEFAULT_SERVER_DATETIME_FORMAT), 'event: incorrect scheduled date')
-
-        # execute event reminder scheduler
-        schedulers[0].execute()
-
-        self.assertTrue(schedulers[0].mail_sent, 'event: reminder scheduler should have sent an email')
-        self.assertTrue(schedulers[0].done, 'event: reminder scheduler should be done')
-
-        mails = self.env['mail.mail'].search([('subject', 'ilike', 'reminder'), ('date', '>=', datetime.datetime.strftime(now, tools.DEFAULT_SERVER_DATETIME_FORMAT))], order='date DESC', limit=3)
-        self.assertEqual(len(mails), 0, 'event: reminder to sent is not empty')
-
         # check subscription scheduler
         schedulers = self.EventMail.search([('event_id', '=', test_event.id), ('interval_type', '=', 'after_sub')])
         self.assertEqual(len(schedulers), 1, 'event: wrong scheduler creation')
         self.assertEqual(schedulers[0].scheduled_date, test_event.create_date, 'event: incorrect scheduled date for checking controller')
 
-        # execute subscription scheduler
-        schedulers[0].execute()
+        # verify that subscription scheduler was auto-executed after each registration
         self.assertEqual(len(schedulers[0].mail_registration_ids), 2, 'event: incorrect number of mail scheduled date')
 
         mails = self.env['mail.mail'].search([('subject', 'ilike', 'subscription'), ('date', '>=', datetime.datetime.strftime(now, tools.DEFAULT_SERVER_DATETIME_FORMAT))], order='date DESC', limit=3)
@@ -76,3 +61,19 @@ class TestMailSchedule(TestEventCommon):
 
         for registration in schedulers[0].mail_registration_ids:
             self.assertTrue(registration.mail_sent, 'event: wrongly confirmed mailing on subscription')
+
+        # check before event scheduler
+        schedulers = self.EventMail.search([('event_id', '=', test_event.id), ('interval_type', '=', 'before_event')])
+        self.assertEqual(len(schedulers), 1, 'event: wrong scheduler creation')
+        self.assertEqual(schedulers[0].scheduled_date, datetime.datetime.strftime(event_date_begin + relativedelta(days=-2), tools.DEFAULT_SERVER_DATETIME_FORMAT), 'event: incorrect scheduled date')
+
+        # execute event reminder scheduler explicitly
+        schedulers[0].execute()
+
+        self.assertTrue(schedulers[0].mail_sent, 'event: reminder scheduler should have sent an email')
+        self.assertTrue(schedulers[0].done, 'event: reminder scheduler should be done')
+
+        mails = self.env['mail.mail'].search([('subject', 'ilike', 'reminder'), ('date', '>=', datetime.datetime.strftime(now, tools.DEFAULT_SERVER_DATETIME_FORMAT))], order='date DESC', limit=3)
+        self.assertEqual(len(mails), 2, 'event: wrong number of reminders in outgoing mail queue')
+
+