Connecting Node js mail listener to IMAP error ("Error: LOGIN failed" when Initializing the Listener)

Question

I'm facing an issue with an email listener in my Node.js application. The email listener was working fine, but suddenly I started encountering an error: LOGIN failed." The email listener is set up to connect to a Microsoft Exchange IMAP server and fetch unread emails. The code snippet I'm using to initialize the email listener is as follows:

private initEmailListener() {
    const dirPath = path.join(__dirname, process.env.directoryPath);
    let mailListener = new MailListener({
        // ... other configuration options ...
        username: process.env.SMTP_USER,
        password: process.env.SMTP_PASSWORD,
        host: process.env.SMTP_HOST,
        // ... other configuration options ...
    });

    mailListener.start();

    mailListener.on("server:connected", function () {
        console.log("imapConnected");
    });

    mailListener.on("error", function (err) {
        console.log(`$$$error : ${err}`); // THIS LINE PRINTS THE ERROR "$$$error : Error: LOGIN failed."
    });

    // ... other event handlers ...
}

And the error:

[connection] Connected to host
<= '* OK The Microsoft Exchange IMAP4 service is ready. [PgBSADAAUAAEEAMAAxADYANgABPAAASwAuC==]'
=> 'A0 CAPABILITY'
<= '* CAPABILITY IMAP4 IMAP4rev1 AUTH=PLAIN AUTH=XOAUTH2 SASL-IR UIDPLUS ID UNSELECT CHILDREN IDLE NAMESPACE LITERAL+'
<= 'A0 OK CAPABILITY completed.'
=> 'A1 LOGIN "[email protected]" "P@55w0rd"'
<= 'A1 NO LOGIN failed.'
$$$error : Error: LOGIN failed.
[connection] Ended
[connection] Closed

Steps Taken:

• I have confirmed that the email server details in the configuration (username, password, host) are correct.
• The code was working fine previously, so I suspect this might be related to a change in the server configuration or security settings.

Expected Outcome: I expect the email listener to connect to the Microsoft Exchange IMAP server and fetch unread emails as before. I'm seeking guidance on troubleshooting this sudden "LOGIN failed" error and understanding what might have caused it. Any insights or suggestions on how to resolve this issue would be greatly appreciated.