Zend_Mail supports the use of SMTP Authentication, which
  can be enabled be passing the 'auth' parameter to the configuration array in
  the Zend_Mail_Transport_Smtp constructor. The available
  built-in Authentication methods are PLAIN, LOGIN and CRAM-MD5 which all
  expect a 'username' and 'password' value in the configuration array.
مثال 20.9. Enabling authentication within Zend_Mail_Transport_Smtp
<?php
require_once 'Zend/Mail.php';
require_once 'Zend/Mail/Transport/Smtp.php';
$config = array('auth' => 'login',
                'username' => 'myusername',
                'password' => 'password');
$transport = new Zend_Mail_Transport_Smtp('mail.server.com', $config);
$mail = new Zend_Mail();
$mail->setBodyText('This is the text of the mail.');
$mail->setFrom('sender@test.com', 'Some Sender');
$mail->addTo('recipient@test.com', 'Some Recipient');
$mail->setSubject('TestSubject');
$mail->send($transport);
| ![[ملاحظة]](images/note.png) | Authentication types | 
|---|---|
| The authentication type is case-insensitive but has no punctuation.
    E.g. to use CRAM-MD5 you would pass 'auth' => 'crammd5' in the
     |