이메일 인증 The following From address failed, MAIL FROM command failed 어떻게하나요?

안녕하세요

config.php

define('G5_SMTP_USE_EXT',  1);

if(defined('G5_SMTP_USE_EXT') && G5_SMTP_USE_EXT == 1){
  define('G5_SMTP', 'smtp.naver.com');
  define('G5_SMTP_PORT', '465');
  define('G5_SMTP_USEAUTH', true);
  define('G5_SMTP_USESECURE', 'ssl');
  define('G5_SMTP_USER', 'testtest_kr');
  define('G5_SMTP_PASS', 'testest123!');
}
else
{
  define('G5_SMTP',      '127.0.0.1');
  define('G5_SMTP_PORT', '25');
}

mailer.lib.php

    try {
        $mail = new PHPMailer(); // defaults to using php "mail()"
        if (defined('G5_SMTP') && G5_SMTP) {
            $mail->IsSMTP(); // telling the class to use SMTP
            $mail->Host = G5_SMTP; // SMTP server
            if(defined('G5_SMTP_PORT') && G5_SMTP_PORT) 
              $mail->Port = G5_SMTP_PORT;

              $mail->SMTPSecure = G5_SMTP_USESECURE;
              $mail->SMTPAuth = G5_SMTP_USEAUTH;
              $mail->Host = G5_SMTP;
              $mail->Username  = G5_SMTP_USER;
              $mail->Password  = G5_SMTP_PASS;
        }
        
        $mail->SMTPDebug = 1;

     
        $mail->CharSet = 'UTF-8';
        $mail->From = $fmail;
        $mail->FromName = $fname;
        $mail->Subject = $subject;
        $mail->AltBody = ""; // optional, comment out and test
        $mail->msgHTML($content);
        $mail->addAddress($to);

이렇게 수정하였는데

2023-07-11 12:47:34 CLIENT -> SERVER: EHLO new.testtest-1.co.kr
2023-07-11 12:47:34 CLIENT -> SERVER: AUTH LOGIN
2023-07-11 12:47:34 CLIENT -> SERVER: bWFy2aa2V40aW5nbW9uc3Rlcl9rcg==
2023-07-11 12:47:34 CLIENT -> SERVER: I2tke1TAyN5zaI5IQ==
2023-07-11 12:47:34 CLIENT -> SERVER: MAIL FROM:<testtest.korea@gmail.com>
2023-07-11 12:47:34 SMTP ERROR: MAIL FROM command failed: 554 5.7.1 The sender address is unauthorized 9IWe3qA4oRd4GiaQJ3ikJgBw - nsmtp
The following From address failed: testtest.korea@gmail.com : MAIL FROM command failed,The sender address is unauthorized 9IWe1qA4o2RdGiaQa4J3ikJgBw - nsmtp,554, 5.7.1 SMTP server error: MAIL FROM command failed Detail: The sender address is unauthorized 9IWeq4A4oRdGiaQJ53iakJgBw - nsmtp SMTP code: 554 Additional SMTP info: 5.7.1
2023-07-11 12:47:34 CLIENT -> SERVER: QUIT

error 메시지가 뜨는데 어떻게 해야 하나요?