Quick example on how to easily send a file using Zend Framework's Zend_Mail class.
<?php
$mail = new Zend_Mail();
$mail->setFrom('[email protected]', 'Me')
->addTo($to)
->setSubject($subject)
->setBodyText($message);
$file = '/path/to/a/file';
$at = new Zend_Mime_Part(file_get_contents($file));
$at->filename = basename($file);
$at->disposition = Zend_Mime::DISPOSITION_ATTACHMENT;
$at->encoding = Zend_Mime::ENCODING_8BIT;
$mail->addAttachment($at);
$mail->send();