535 Incorrect authentication data to SES using PHPMailer and SES SMTP username and password

We are trying to connect using PHPMailer to Amazon SES.

This is an older system on PHP 7.2., I know...

  $mail = new PHPMailer;
            $mail->isSMTP();                                                        // Set mailer to use SMTP
            $mail->SMTPDebug = 4;
            $mail->Host = 'email-smtp.us-east-1.amazonaws.com';           // Specify main and backup SMTP servers
            //$mail->Host = 'email-smtp.us-west-2.amazonaws.com';
            $mail->SMTPAuth = true;                                             // Enable SMTP authentication
            $mail->Username =  'AKIA[REDACTED]NPK';                           // SMTP username
            $mail->Password = 'BA7EW[REDACTED]vJbHUjvp';                           // SMTP password
            $mail->SMTPSecure = 'tls';                                          // Enable TLS encryption, `ssl` also accepted
            $mail->Port = 587;
            $mail->SMTPOptions = array(
    'ssl' => array(
        'verify_peer' => false,
        'verify_peer_name' => false,
        'allow_self_signed' => true
    )
);

 $mail->setFrom("no-reply@VALIDATEDDOMAIN.com");

            $mail->addAddress(VALIDATEDEMAIL@ourdomain.com); 
            $mail->isHTML(true);
            $mail->Subject = $subject;
            $mail->Body = $body;
            if(!$mail->send()){
echo $mail->ErrorInfo;
}

The username and password was create in the create SMTP credentials, and the CSV was downloaded.

This is the CSV:

IAM User Name,Smtp Username,Smtp Password
"test_user",AKIA[REDACTED]NPK,BA7EW[REDACTED]vJbHUjvp

Multiple ones were created and tested.

Our test region is apparently US-WEST-2. but we ceate them in US-EAST-1. Both were tested, as you can see in the commented out line above.

When I download the list of users

I get:

user,arn,user_creation_time,password_enabled,password_last_used,password_last_changed,password_next_rotation,mfa_active,access_key_1_active,access_key_1_last_rotated,access_key_1_last_used_date,access_key_1_last_used_region,access_key_1_last_used_service,
test_user,arn:aws:iam::7389[REDACTED]188:user/test_user,2022-12-12T20:00:12+00:00,false,N/A,N/A,N/A,false,true,2022-12-12T20:00:12+00:00,N/A,N/A,N/A,false,N/A,N/A,N/A,N/A,false,N/A,false,N/A

Here is the level 3 logs from PHPMailer, edited for confidentiality:

2022-12-13 14:21:58 Connection: opening to email-smtp.us-east-1.amazonaws.com:587, timeout=300, options=array ( 'ssl' => array ( 'verify_peer' => false, 'verify_peer_name' => false, 'allow_self_signed' => true, ),)
2022-12-13 14:21:58 Connection: opened
2022-12-13 14:21:58 SMTP INBOUND: "220-##MYSERVER## ESMTP Exim 4.95 #2 Tue, 13 Dec 2022 09:21:58 -0500"
2022-12-13 14:21:58 SMTP INBOUND: "220-We do not authorize the use of this system to transport unsolicited,"
2022-12-13 14:21:58 SMTP INBOUND: "220 and/or bulk e-mail."
2022-12-13 14:21:58 SERVER -> CLIENT: 220-##MYSERVER## ESMTP Exim 4.95 #2 Tue, 13 Dec 2022 09:21:58 -0500 220-We do not authorize the use of this system to transport unsolicited, 220 and/or bulk e-mail.
2022-12-13 14:21:58 CLIENT -> SERVER: EHLO ##MYDOMAIN##
2022-12-13 14:21:58 SMTP INBOUND: "250-##MYSERVER## Hello ##MYDOMAIN## [##MYSERVERIP###]"
2022-12-13 14:21:58 SMTP INBOUND: "250-SIZE 52428800"
2022-12-13 14:21:58 SMTP INBOUND: "250-8BITMIME"
2022-12-13 14:21:58 SMTP INBOUND: "250-PIPELINING"
2022-12-13 14:21:58 SMTP INBOUND: "250-PIPE_CONNECT"
2022-12-13 14:21:58 SMTP INBOUND: "250-AUTH PLAIN LOGIN"
2022-12-13 14:21:58 SMTP INBOUND: "250-STARTTLS"
2022-12-13 14:21:58 SMTP INBOUND: "250 HELP"
2022-12-13 14:21:58 SERVER -> CLIENT: 250-##MYSERVER## Hello ##MYDOMAIN## [##MYSERVERIP###]250-SIZE 52428800250-8BITMIME250-PIPELINING250-PIPE_CONNECT250-AUTH PLAIN LOGIN250-STARTTLS250 HELP
2022-12-13 14:21:58 CLIENT -> SERVER: STARTTLS
2022-12-13 14:21:58 SMTP INBOUND: "220 TLS go ahead"
2022-12-13 14:21:58 SERVER -> CLIENT: 220 TLS go ahead
2022-12-13 14:21:58 CLIENT -> SERVER: EHLO ##MYDOMAIN##
2022-12-13 14:21:58 SMTP INBOUND: "250-##MYSERVER## Hello ##MYDOMAIN## [##MYSERVERIP###]"
2022-12-13 14:21:58 SMTP INBOUND: "250-SIZE 52428800"
2022-12-13 14:21:58 SMTP INBOUND: "250-8BITMIME"
2022-12-13 14:21:58 SMTP INBOUND: "250-PIPELINING"
2022-12-13 14:21:58 SMTP INBOUND: "250-PIPE_CONNECT"
2022-12-13 14:21:58 SMTP INBOUND: "250-AUTH PLAIN LOGIN"
2022-12-13 14:21:58 SMTP INBOUND: "250 HELP"
2022-12-13 14:21:58 SERVER -> CLIENT: 250-##MYSERVER## Hello ##MYDOMAIN## [##MYSERVERIP###]250-SIZE 52428800250-8BITMIME250-PIPELINING250-PIPE_CONNECT250-AUTH PLAIN LOGIN250 HELP
2022-12-13 14:21:58 Auth method requested: UNSPECIFIED
2022-12-13 14:21:58 Auth methods available on the server: PLAIN,LOGIN
2022-12-13 14:21:58 Requested auth method not available:
2022-12-13 14:21:58 Auth method selected: LOGIN
2022-12-13 14:21:58 CLIENT -> SERVER: AUTH LOGIN
2022-12-13 14:21:58 SMTP INBOUND: "334 VXNlcm5hbWU6"
2022-12-13 14:21:58 SERVER -> CLIENT: 334 VXNlcm5hbWU6
2022-12-13 14:21:58 CLIENT -> SERVER: QUtJQTJZRE1IU0QyQU1HRlpOUEs=
2022-12-13 14:21:58 SMTP INBOUND: "334 UGFzc3dvcmQ6"
2022-12-13 14:21:58 SERVER -> CLIENT: 334 UGFzc3dvcmQ6
2022-12-13 14:21:58 CLIENT -> SERVER: QkE3RVcyYUdNaUMzYTFYWFVXOU80QkQyak51aTluN2IzNTZxdkpiSFVqdnA=
2022-12-13 14:22:00 SMTP INBOUND: "535 Incorrect authentication data"
2022-12-13 14:22:00 SERVER -> CLIENT: 535 Incorrect authentication data
2022-12-13 14:22:00 SMTP ERROR: Password command failed: 535 Incorrect authentication data
SMTP Error: Could not authenticate.
2022-12-13 14:22:00 CLIENT -> SERVER: QUIT
2022-12-13 14:22:00 SMTP INBOUND: "221 ##MYSERVER## closing connection"
2022-12-13 14:22:00 SERVER -> CLIENT: 221 ##MYSERVER## closing connection
2022-12-13 14:22:00 Connection: closed
SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting