Zend_Mail also supports the use of either TLS or SSL to
secure a SMTP connection. This can be enabled be passing the 'ssl' parameter
to the configuration array in the Zend_Mail_Transport_Smtp
constructor with a value of either 'ssl' or 'tls'. A port can optionally be
supplied, otherwise it defaults to 25 for TLS or 465 for SSL.
例 20.9. Enabling a secure connection within Zend_Mail_Transport_Smtp
<?php
require_once 'Zend/Mail.php';
require_once 'Zend/Mail/Transport/Smtp.php';
$config = array('ssl' => 'tls',
'port' => 25); // Optional port number supplied
$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);