CDONTS will not send to MSN

I am using myMail (CDONTS) to send email from my IIS based ASP page. My problem is that it will not send to an MSN email address. The message just remains in my mailroot/queue. It quite happy sends to the majority of other domains.

I will appreciate any help that that is given.

Thanking You,
Harold Clements

Thanks for your reply it is very much appreciated.

The header of the emails looks like this:

Return-path: <>

Envelope-to: registration@cpl.netnutz.co.uk

Delivery-date: Mon, 18 Aug 2003 10:57:23 +0100

Received: from [80.3.177.36] (helo=haroldjclements)

      by clustermail.minx.net.uk with esmtp (Exim 3.22 #6)

      id 19oglP-0003oL-00

      for registration@cpl.netnutz.co.uk; Mon, 18 Aug 2003 10:57:23 +0100

From: postmaster@haroldjclements

To: registration@cpl.netnutz.co.uk

Date: Mon, 18 Aug 2003 10:57:23 +0100

MIME-Version: 1.0

Content-Type: multipart/report; report-type=delivery-status;

      boundary="9B095B5ADSN=_01C365089547AAB00000002Charoldjclements"

Message-ID: <XRPmcarcR00000005@haroldjclements>

Subject: Delivery Status Notification (Delay)

I apologise in advance for my ignorance in this matter.

Would the problem be with the return-path being <> (empty) if so how do you specify a return path using NewMail?

I am not 100% sure how CDONTS works. I take it that it uses your ISP's SMTP but I am not too sure how as I have not told it at any time of ISP's SMTP Address.  Also I not to sure how to do what you originally suggested about checking the postmaster/catchall account of my server!
None of my sent emails are saved and my computers name is haroldjclements if this helps.

Thanks for your time,

Harold Clements