How to use non SMTP transport in log4js smtp appender?

If you read the log4js documentation for SMTP appender, you'll see example for SMTP transport, which even does not work well with latest nodemailer (I'm using nodemailer 1.3.0 at the time of writting).

Docs show this as example bad config:

{ "appenders": [
    {
        "type": "smtp",
        "recipients": "foo@bar.com",
        "sendInterval": 60,
        "transport": "SMTP",
        "SMTP": {
            "host": "smtp.gmail.com",
            "secureConnection": true,
            "port": 465,
            "auth": {
                "user": "foo@bar.com",
                "pass": "bar_foo"
            }
        }
    }
] }

How to change config to use transport other than SMTP? What I want is to configure log4js to work with SendGrid.