This script reads a .CSV file with a field order of email address, domain, password, and quota and issues messages to distribute the new passwords.

<?php
$sData=file_get_contents('email_accounts.txt');
$aData=explode("\n",$sData);
foreach ($aData as $k => $v)
{
        $d=trim($v);
        /* Disregard blank lines */
        if ($d!=='')
        {
                $m=explode(',',$d);
                $sMessage='Your new email account password is '.$m[2].PHP_EOL.PHP_EOL;
                $sMessage.=file_get_contents('message.txt');
                $headers = 'From: webmaster- @ -example.com' . PHP_EOL .
                        'Reply-To: webmaster- @ -example.com' . PHP_EOL .
                        'X-Mailer: PHP/' . phpversion();
                mail ($m[0],'New email access',$sMessage,$headers);
        }
}

?>

Sample message.txt

The new server is scheduled to go live at DateTime.

You will have to enter the new password to use your email after DateTime.

You may change the password, after DateTime, by logging in to http://example.com:2095, with your full email address and the
password above, and using the ‘Change Email Password’ feature.

If you have any questions, please let me know.

Your name
email
Phone