Consultation nodemailer nodejs

I'm trying to send a message on a network with an active proxy ip proxy: 192.168.2.1: 3128

I configure my options on nodemailer

var smtpConfig = {
    host: 'smtp.gmail.com',
    port: 465,
      auth: {
        user: mailconfig.email,
        pass: mailconfig.password
    },
    //proxy config 
    // assumes a HTTP proxy running on port 3128 
    proxy: 'http://192.168.2.1:3128'
};

var smtptransport=nodemailer.createTransport(smtpConfig);

But I get the following error:

  

Invalid response from proxy 403

I already checked everything, and I do not know what the error might be.