title: Nodemailer is only sending emails for gmail
body: <p>i'm using Oauth2 and nodemailer to send emails using nodejs.
  when i send the email to a gmail email ex: <strong>example@gmail.com</strong> everything is working fine,
  but when i try to send the email to a hotmail email ex: <strong>example@hotmail.com</strong>, it's returning for me a success message, but when i check my email, i see that the email was not sent.</p>
  <p>this is my code:</p>
  <pre><code>const nodemailer = require('nodemailer');
  const { google } = require('googleapis');
  
  const CLIENT_ID = 'My client id';
  const CLEINT_SECRET = 'the secret';
  const REDIRECT_URI = 'https://developers.google.com/oauthplayground';
  const REFRESH_TOKEN = 'the refresh token';
  
  
  const oAuth2Client = new google.auth.OAuth2(
    CLIENT_ID,
    CLEINT_SECRET,
    REDIRECT_URI
  );
  oAuth2Client.setCredentials({ refresh_token: REFRESH_TOKEN });
  
  
  
  
  exports.sendEmail = async (email, subject, text, html) =&gt; {
  
  
    try {
      const accessToken = await oAuth2Client.getAccessToken();
      const transporter = nodemailer.createTransport({
        service: 'gmail',
        auth: {
          type: 'OAuth2',
          user: process.env.EMAIL,
          clientId: CLIENT_ID,
          clientSecret: CLEINT_SECRET,
          refreshToken: REFRESH_TOKEN,
          accessToken: accessToken,
        }
      });
  
      const mailOptions = {
        from: 'Twitter from AliExpress &lt;process.env.EMAIL&gt;',
        to: email,
        subject: subject,
        text: text,
        html: html
      };
  
      const result = await transporter.sendMail(mailOptions);
      return result
    }
  
    catch (error) {
      let err = new Error('Email err: '+ error.message)
      return err
  
    }
  }
  
  </code></pre>
  <p>Thank you.</p>