diff --git a/addons/mass_mailing/wizard/mailing_mailing_test.py b/addons/mass_mailing/wizard/mailing_mailing_test.py
index 8dbeff90089..86c1ba2dbe1 100644
--- a/addons/mass_mailing/wizard/mailing_mailing_test.py
+++ b/addons/mass_mailing/wizard/mailing_mailing_test.py
@@ -36,6 +36,7 @@ class TestMassMailing(models.TransientModel):
                 'mailing_id': mailing.id,
                 'attachment_ids': [(4, attachment.id) for attachment in mailing.attachment_ids],
                 'auto_delete': True,
+                'mail_server_id': mailing.mail_server_id.id,
             }
             mail = self.env['mail.mail'].sudo().create(mail_values)
             mails_sudo |= mail