When using Zend_mail, my emails seem to be considered spam, sent via Outlook and not?

Question

I am trying to figure out a choice on a mailing list system. I understand the basic principles and design, but I had a problem with being picked up as spam.

If I send an html email address through Outlook via [e-mail] , it works fine and is not considered as spam. When I use the Zend_mail object to send mail, which it sends, but is considered as spam in test mailboxes, I also send it.

This is the im code used to send the email item.

//send an email
        $mail = new Zend_Mail();
        $config = array('auth' => 'login','username' => '[e-mail]','password' => 'mypassword');
        $transport = new Zend_Mail_Transport_Smtp('mail.domain.com', $config);
        $mail->setSubject($item->title);
        $mail->setFrom("[e-mail]");
        $mail->addTo($item->email, $item->forename);
        //$mail->setBodyText($item->contentPlain);
        $mail->setBodyHtml($item->contentHTML);
        $mail->send($transport);

, im smtp , , . , , !

, :

, , , ? IP- 10

    Received: (qmail 1436 invoked from network); 14 Aug 2009 16:02:10 +0100
    Received: from clientdomain1.co.uk (HELO localhost) (91.192.***.196)
  by clientdomain2.info with SMTP; 14 Aug 2009 16:02:10 +0100
Subject: Manchester 2 Day Seminar: Dealing with difficult people
From: [e-mail]
To: Andi <[e-mail]>
Date: Fri, 14 Aug 2009 15:02:10 +0000
Content-Type: text/html; charset=iso-8859-1
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
MIME-Version: 1.0

Answer 1

"Roll your own mail" . , , .

, , , , , (, @foo.com, foo.com smtp). -.

Answer 2

Outlook. - ? ? ?

Answer 3

, localhost:

$protocol = new Zend_Mail_Protocol_Smtp('localhost');
$protocol->connect();
$protocol->helo('mail.yourserver.com'); //**DO THIS**

$transport->setConnection($protocol);