var transporter = nodemailer.createTransport(smtpTransport({
  host: 'smtp.office365.com',
  port: 25, // have tried 465
  secureConnection: secure,
  auth: {
    user: username,
    pass: password
  },
  tls: {
    rejectUnauthorized: false // don't verify certificates
  },
  ignoreTLS: false // don't turn off STARTTLS support
}));

[Error: Invalid login: 504 5.7.4 Unrecognized authentication type]
code: 'EAUTH',
response: '504 5.7.4 Unrecognized authentication type',
responseCode: 504

var transporter = nodemailer.createTransport({
        host: 'smtp.office365.com', // Office 365 server
        port: 587,     // secure SMTP
        secure: false, // false for TLS - as a boolean not string - but the default is false so just remove this completely
        auth: {
            user: username,
            pass: password
        },
        tls: {
            ciphers: 'SSLv3'
        }
    });

requireTLS: true