Configure a email server: hMailServer

I started and have a fully functional email server at amazon using hMailServer. I want a diagnose and recomendations to increase the security of this server. I will provide access to an image of the server and I want back a report with what to change in that server to I apply in production server. Actually we are ranked with 66% of security in [login to view URL] and I'd like to have at least 90%. The key features do improve is: - DKIM Signature; - MX Connection Test; - Reverse DNS Test; - DNSBL Verification Test; - Auth using SSL/TLS, STARTTLS on ports 25, 465, 587; - SPF server test; - SPF client test; - Open Relay and Email Format Test; - SMTP Plain Text Authentication Test; - POP3 Connection Test; - IMAP Connection and Authentication Test;