If you ever need to get your Zend_Form_Element_File to be attached to your Zend_Mail, here’s how it’s done!

$mail = new Zend_Mail();
$at = new Zend_Mime_Part(file_get_contents($form->upload->getFileName()));
            $at->type           = $form->upload->getMimeType();
            $at->disposition = Zend_Mime::DISPOSITION_ATTACHMENT;
            $at->encoding    = Zend_Mime::ENCODING_BASE64;
            $at->filename    = basename($form->upload->getFileName());
            $mail->addAttachment($at);