Please check the knowledge base article 500525 : ESRS VE: ESRS being reported as open SMTP relay (CVE-1999-0512) [URL]  A small configuration change will prevent the SMTP service from acting as a relay.  Regards Frank
Our OpSec team is complaining that our deployment of ESRS is running as an open relay.  The relevant link is from Tenable.  [URL]  It NTMail3 Arbitrary Mail Relay.  I don't see any misconfiguration in the console GUI.  Is there any way of preventing the security scan from showing this as an open relay?
SMTP Open Relay