1. To configure a StartTLS connection to the server, use the dsconfig command. 
    $ bin/dsconfig create-external-server \
  --server-name myTLSServer --type smtp \ 
  --set server-host-name:tls.smtp.example.com \
  --set server-port:587 \ 
  --set smtp-security:starttls \
  --set user-name:MyAccountName \ 
  --set password:AAD5yZ+DjvwiYkBSMer6GQ6B3szQ6gSSBjA=
  2. To configure a newly-created SMTP server, use the dsconfig command. 
    $ bin/dsconfig set-global-configuration-prop \
  -set smtp-server:myTLSServer

    This command adds the server to the global list of mail servers that Directory Server can use.