We are currently configuring dynamicID on a remote access gateway. I have tested with cloud SMTP servers (Sendgrid and AWS SES), and the OTPs were delivering on the R80.40 gateway.
However, we have an internal SMTP relay, and we want to use that instead. We have tested, and the error says "dynamicId sending failure, press r to retry".
The logs show that SMTP traffic was sent to the Internal relay and we have whitelisted the IPs of the gateway, but no OTPs are being delivered. Our network topology is Checkpoint Security gateways on the perimeter, and Palo Alto firewalls to filter internal traffic.
No traffic logs show traffic from the checkpoint gateway to the SMTP relay on Palo Alto either. A major reason for using the internal SMTP relay is because our ISPs here block SMTP traffic over port 587, and so we cannot ideally use the cloud SMTP servers.
Thanks for reading through, and for your assistance. I can provide any more information as needed. Thanks.