You already got a CA in place. Use your CA to generate a new certificate for your mail server. Add that certificate and your Root CA to your mail server setup.

  • Use openssl s_client to connect to your mail server

  • verify that you set the certificate for incoming and outgoing connections

    • send an email with starttls using a MUA.

    • Use a MUA to send an email to your HdM Account using your mail server system as a relay.

  • both connections should be secured via TLS. Look in your mail.log to verify this