Invalid login sequence while waiting for server challenge string: 504 5.7.4 Unrecognized authentication type

[heresmyusername]

Hello, I am trying to user a 3rd party program which uses nodemailer to send emails with Microsoft Exchange. When I try to send an email, the API log says "Invalid login sequence while waiting for server challenge string: 504 5.7.4 Unrecognized authentication type". Please could someone help me understand why this is happening and how I can fix it? Below is the code:

// NTLM support: https://github.com/nodemailer/nodemailer-ntlm-auth
// Steps:
// 1) run "npm install nodemailer-ntlm-auth" in "echo $(countly dir)"
// 2) rename or copy this file to countly/extend/mail.js

var nodemailer = require("nodemailer");
var nodemailerNTLMAuth = require("nodemailer-ntlm-auth");

module.exports = function(mail) {
mail.smtpTransport = nodemailer.createTransport({
host: 'smtp.office365.com',
port: 587,
auth: {
type: 'custom',
method: 'NTLM',
user: user,
pass: pass,
},
customAuth: {
NTLM: nodemailerNTLMAuth
}
});

mail.sendMail = function(message, callback) {
message.from = from;
mail.smtpTransport.sendMail(message, function(error) {
if (error) {
console.log("Error sending email");
console.log(error.message);
}

if (callback) {
callback(error);
}
});
};
};