Running security scan in our organization.
When it comes to our e-mail secure gateway (mx record server) an issue is found from Nessus:
The remote SMTP server appears to allow mail relaying. This means that an unauthenticated, remote user could possibly use the mail server to send messages to the world, thus wasting network bandwidth and computer resources. Such servers are targeted by spammers for sending unsolicited bulk email (UBE).
Is this not applicable because this is our e-mail secure gateway that receives e-mail from the internet to filter and pass on to our Exchange servers?
Or is a email secure gateway not support to allow relay?
Just wondering if I need to tighten security at all.