Dyn Standard SMTP and Fortigate

Hello friends of the community, today I want to ask for help with a problem using the Dyn Standard SMTP service from Fortigate router.

The problem is that when the Fortigate Router is configured to send critical alerts using as outgoing mail server http://outbound.mailhop.org just do not leave the mail but to use any other mail server to send out.

I hope to help this community concern.