Sendmail无法发送到某些域

Question

I've got a small site set up that allows people to send a prewritten email to their representatives, by putting in their own email and their representatives email. It's set up using sendmail, and works for sending to gmail, a personal email I have, and various other domains. However, it fails to send to the one domain that I need it to send to. I get the following fault

<[e-mail]>: Sender address rejected: Domain not found

I've been looking through god knows how many things and I can't seem to figure it out seeing as it's working for everything else.

Hopefully someone can explain it. Cheers!

<?php
$field_name = $_POST['cf_name'];
$field_email = $_POST['cf_email'];
$field_recipient = $_POST['cf_recipient'];

$subject = 'Message Regarding Cuts in the Mental Health Budget';

$body_message = 'hello';

$headers = 'From: '.$field_email."
";

$headers .= 'Reply-To: '.$field_email."
";
$headers .= 'Return-Path: '.$field_email;

$mail_status = mail($field_recipient, $subject, $body_message, $headers);

if ($mail_status) { ?>
    <script language="javascript" type="text/javascript">
        alert('Thank you for the message. We hope this will get the TDs in gear.');
        window.location = 'index.html';
    </script>
<?php
}
else { ?>
    <script language="javascript" type="text/javascript">
        alert('Message failed. Please, make sure all boxes have been filled and try again.');
        window.location = 'index.html';
    </script>
<?php
}
?>

Answer 1

You have failed to set "envelope sender" email address used in MAIL FROM: command in SMTP sessions. It can be set by passing -f command line option to sendmail. See additional_parameters in mail documentation