Nodejs Nodemailer : Sendgrid SMTP username & password to API key using existing code error : 550

Question

Currently im using sendgrid using nodejs library “('nodemailer')” TransporterOption:

config:

 transporterOption: {
        host: process.env.SMTP_HOST, // smtp.sendgrid.net
        pool: true,
        maxConnections: 20,
        rateDelta: 1000,
        rateLimit: 150,        
        auth: {
            user: process.env.USER_NAME,
            pass: process.env.PASSWORD
        }
    },

sending code :

const config = require('./config');
const nodeMailer = require('nodemailer');
const htmlToText = require('nodemailer-html-to-text').htmlToText;



const transporter = nodeMailer.createTransport(config.transporterOption);

transporter.use('compile', htmlToText());


try {

    let mailOptions = {
        headers: { 'X-SMTPAPI': `{"category":["${myid}"]}` },
        from: `"myname" <${toemail}>`,
        replyTo: `"myname" <${toemail}>`,
        to: `"name" <${emailAdr}>`,
        subject: mysubject,
        text: mytextbody,
        html: myhtmlbodymsg

    }
} catch (e) {

    console.log(e);
}

Working FINE with no issues.

migrating from username/password to API key when passing api_key in response getting this error "Mail command failed: 550 Unauthenticated senders not allowed”

option 1:

transporterOption: {
        host: process.env.SMTP_HOST, // smtp.sendgrid.net
        pool: true,
        maxConnections: 20,
        rateDelta: 1000,
        rateLimit: 150,        
        auth: {
            api_key: process.env.SENDGRID_API_KEY // fakeKEY.kashdkjhjkdhsakjdhksajhd
        }
    },

"err":{"message":"Missing credentials for "PLAIN"","name":"Error","stack":"Error: Missing credentials for "PLAIN"\n

Option 2 :

transporterOption: {
        host: process.env.SMTP_HOST, // smtp.sendgrid.net
        pool: true,
        maxConnections: 20,
        rateDelta: 1000,
        rateLimit: 150,        
        auth: {
            Username: process.env.USER_NAME, //’apikey’
            Password: process.env.SENDGRID_API_KEY // fakekeyssssjhkjsahdkjsahdkjhsa
        }
    },

Error : “{"message":"Mail command failed: 550 Unauthenticated senders not allowed","name":"Error","stack":"Error: Mail command failed: 550 Unauthenticated senders not allowed\n”

Option 3 :

transporterOption: {
        host: process.env.SMTP_HOST, // smtp.sendgrid.net
        pool: true,
        maxConnections: 20,
        rateDelta: 1000,
        rateLimit: 150,        
        auth: {
            api_user: 'apikey',
        api_key: process.env.SENDGRID_API_KEY // fakekeyssssjhkjsahdkjsahdkjhsa
        }
    },

Error : “{"message":"Mail command failed: 550 Unauthenticated senders not allowed","name":"Error","stack":"Error: Mail command failed: 550 Unauthenticated senders not allowed\n”

Answer 1

I also needed to migrate from basic authentication to API keys for Sendgrid.
I tried to use the API keys in the following way and probably works but do not know if we are still using basic authentication by this way which will soon fail due to compulsory 2FA.
Let me know if what we are doing here is correct.

// This below auth object is specific to NODEMAILER configuration options
// This is NOT the same for sendgrid native API configuration

// you can try with your keys named Username/Password but mine works with user/pass
auth: {
  'user': 'apikey', // <--- keep as is
  'pass': 'SG.aslknwefn_RANDOM_FAKE_KEY', // <--- your api key
}

sendgrid reference links:
https://sendgrid.com/docs/for-developers/sending-email/upgrade-your-authentication-method-to-api-keys
https://sendgrid.com/docs/for-developers/sending-email/authentication/