Message-ID showing up in html emails outlook

Dear All, I'm composing a HTML email. When I send it out it looks fine in all clients except outlook which shows the Message-ID. Heres the basic code: $html="<html><body><img src=\"http://celebrityaccess.com/images/marketing/ca_july_advert.jpg\"></body></html>"; $recip = "someuser@domain.com"; $subject = "My Subject"; $body = $html; $to = $recip; $headers = 'From:someuser@domain.com ' . "\r\n" . 'Reply-To:someuser@domain.com ' . "\r\n" .'Content-type: text/html;' . "\r\n" . 'MIME-Version: 1.0'."\r\n"; mail($to,$subject,$body,$headers); Any thoughts? -- Paul Nowosielski Webmaster