java: javax.mail fails to send email to Gmail account returning: 535-5.7.8 Username and Password not accepted. Learn more at

 >PROBLEM

Attempt to send email fails returning the following message:

javax.mail fails to send email to Gmail account returning: 535-5.7.8 Username and Password not accepted. Learn more at

>SOLUTION

Since 05/30/2022 , you may lose access to apps that are using less secure sign-in technology.

To help keep your account secure, Google will no longer support the use of third-party apps or devices which ask you to sign in to 

your Google Account using only your username and password. 

To solve this issue, there are options available.
A fast approach is to use the "App Password" option that generates a new password for the application to get access.

Using this option, the only thing necessary is to replace the previous user's password in your java code with the new password generated.

Point to: Google's doc for this issue.

Go to "Fix Problems", then "Use an App Password".

Follow by the pictures.

>Extra

Configuration used:

PROPS.put("mail.debug", "false");

PROPS.put("mail.smtp.port", "587");

PROPS.put("mail.smtp.auth", "true");

PROPS.put("mail.smtp.starttls.enable", "true");

PROPS.put("mail.smtp.host", "smtp.googlemail.com");

PROPS.put("mail.smtp.ssl.trust", "smtp.gmail.com");

PROPS.put("mail.smtp.ssl.protocols", "TLSv1.2");

PROPS.put("mail.smtp.host", "smtp.gmail.com");

session = Session.getInstance(PROPS, new javax.mail.Authenticator() {

@Override

protected PasswordAuthentication getPasswordAuthentication() {

return new PasswordAuthentication(SENDER, PASSWORD);

}

});

>ENV

Java (javax.mail)
Windows