The following script is an example of how to use authentication in send out bound mail through a form.

In order to better protect sbwh from the threat of mail form exploitation, we are now requiring the use of authentication in all php scripts.
To be able to send mail out through your php enabled website, you must have a valid and active email account with us.
Most likely you already have an email account under your domain. You can simply use the email you are familiar with to send out mail through your website.

For example:

If your domain is sbwh.com, and you have mailto:admin@sbwh.com as your email address, you would use mail.sbwh.com as the mail server, admin @ sbwh.com as the username and your password as the password.

<?php
/* * * * * * * * * * * * * * SEND EMAIL FUNCTIONS * * * * * * * * * * * * * */

//Authenticate Send - 21st March 2005
//This will send an email using auth smtp and output a log array
//logArray - connection,

function authSendEmail($from, $namefrom, $to, $nameto, $subject, $message)
{
//SMTP + SERVER DETAILS
/* * * * CONFIGURATION START * * * */
$smtpServer = "mail.server.com";
$port = "25";
$timeout = "30";
$username = "smtpusername";
$password = "smtppassword";
$localhost = "localhost";
$newLine = "\r\n";
/* * * * CONFIGURATION END * * * * */

//Connect to the host on the specified port
$smtpConnect = fsockopen($smtpServer, $port, $errno, $errstr, $timeout);
$smtpResponse = fgets($smtpConnect, 515);
if(empty($smtpConnect))
{
$output = "Failed to connect: $smtpResponse";
return $output;
}
else
{
$logArray['connection'] = "Connected: $smtpResponse";
}

//Request Auth Login
fputs($smtpConnect,"AUTH LOGIN" . $newLine);
$smtpResponse = fgets($smtpConnect, 515);
$logArray['authrequest'] = "$smtpResponse";

//Send username
fputs($smtpConnect, base64_encode($username) . $newLine);
$smtpResponse = fgets($smtpConnect, 515);
$logArray['authusername'] = "$smtpResponse";

//Send password
fputs($smtpConnect, base64_encode($password) . $newLine);
$smtpResponse = fgets($smtpConnect, 515);
$logArray['authpassword'] = "$smtpResponse";

//Say Hello to SMTP
fputs($smtpConnect, "HELO $localhost" . $newLine);
$smtpResponse = fgets($smtpConnect, 515);
$logArray['heloresponse'] = "$smtpResponse";

//Email From
fputs($smtpConnect, "MAIL FROM: $from" . $newLine);
$smtpResponse = fgets($smtpConnect, 515);
$logArray['mailfromresponse'] = "$smtpResponse";

//Email To
fputs($smtpConnect, "RCPT TO: $to" . $newLine);
$smtpResponse = fgets($smtpConnect, 515);
$logArray['mailtoresponse'] = "$smtpResponse";

//The Email
fputs($smtpConnect, "DATA" . $newLine);
$smtpResponse = fgets($smtpConnect, 515);
$logArray['data1response'] = "$smtpResponse";

//Construct Headers
$headers = "MIME-Version: 1.0" . $newLine;
$headers .= "Content-type: text/html; charset=iso-8859-1" . $newLine;
$headers .= "To: $nameto <$to>" . $newLine;
$headers .= "From: $namefrom <$from>" . $newLine;

fputs($smtpConnect, "To: $to\nFrom: $from\nSubject: $subject\n$headers\n\n$message\n.\n");
$smtpResponse = fgets($smtpConnect, 515);
$logArray['data2response'] = "$smtpResponse";

// Say Bye to SMTP
fputs($smtpConnect,"QUIT" . $newLine);
$smtpResponse = fgets($smtpConnect, 515);
$logArray['quitresponse'] = "$smtpResponse";
}
?>

Example2: mail call replacemnt and authentication function

<?php
//new function

$to = "post@example.com";
$nameto = "Who To";
$from = "post@example.com";
$namefrom = "Who From";
$subject = "Hello World Again!";
$message = "World, Hello!"
authSendEmail($from, $namefrom, $to, $nameto, $subject, $message);
?>

The below would be created as mail.php

<?php
require_once "Mail.php";

$from = "Sandra Sender < sender@example.com >";
$to = "Ramona Recipient < recipient@example.com >";
$subject = "Hi!";
$body = "Hi,\n\nHow are you?";

$host = "mail.example.com";
$username = "smtp_username";
$password = "smtp_password";

$headers = array ('From' => $from,
  'To' => $to,
  'Subject' => $subject);
$smtp = Mail::factory('smtp',
  array ('host' => $host,
    'auth' => true,
    'username' => $username,
    'password' => $password));

$mail = $smtp->send($to, $headers, $body);

if (PEAR::isError($mail)) {
  echo("<p>" . $mail->getMessage() . "</p>");
 } else {
  echo("<p>Message successfully sent!</p>");
 }
?>