Ghost CMS - how to set it to use smtp email via postfix

It is really not easy task to set Ghost CMS to use localhost postfix. Actually everything is based on Nodemailer javascript module.

Here is my working config:

  "mail": {
    "from": "'Ostreff Ghost Support' <ghost@ostreff.info>",
    "transport": "SMTP",
    "options": {
        "service": "postfix",
        "host": "localhost",
        "port": "587",
        "secure": false,
        "secureConnection": false,
        "ignoreTLS": false,
        "requireTLS":false,
        "auth": {
                "user": "ghost@ostreff.info",
                "pass": "XXXXXX { hidden } XXXXXX"
         },
        "tls": {
               "rejectUnauthorized": false,
               "servername": "mail.ostreff.info"
        },
        "debug": true,
        "log": true
    }
  },