phpmailer - The following SMTP Error: Data not accepted

Question

I'm trying to figure out this issue for 6 hours. But there is nothing to make sense. Here is the scenario; There is a well formatted HTML template.

$mail_body = '
    <b>Message Num :</b> 769<br />
    <b>Message Date :</b> 2013-04-08 09:03:21<br />
    <b>Name :</b> John Doe<br />
    <b>Phone :</b> 123456789<br />
    <b>E-mail :</b> [email protected]<br />
    <b>Message :</b> Here is the message info<br />
';

Here is the array of recipients' mails;

$recipients = array("[email protected]","[email protected]");

Everything looks fine and email ready to send.Here is the phpmailer config;

$mail = new PHPMailer(); 
$mail->IsSMTP();
$mail->From = "[email protected]"; 
$mail->FromName = "TEST";
$mail->WordWrap = 50;

foreach($recipients as $mail_add) {
    $mail->AddAddress($mail_add);
}
$mail->IsHTML(true);
$mail->Subject = "TEST Subject";
$mail->Body = $mail_body;
if(!$mail->Send()) {
    echo $mail->ErrorInfo;
} else { 
        echo "Mail sent...";
}

Everything is same when I test it. But sometimes email was sent. Sometimes it was not sent. Give me the following error : The following SMTP Error: Data not accepted.

I hope I explained

Answer 1

your server dosen't allow different sender and username you should config: $mail->From like $mail->Username