What is the solution for "Mail rejected by Windows Live Hotmail for policy reasons"

Dear Experts,

We can send email to Hotmail.com but whenever we are sending any email to hotmail.com, we are getting this error :-

550 SC-002      Mail rejected by Windows Live Hotmail for policy reasons. The mail server IP connecting to Windows Live Hotmail has exhibited namespace mining behavior. If you are not an email/network admin please contact your Email/Internet Service Provider for help.


Here is the full error message for your referance:-


_____________________________________________
From: Microsoft Exchange
Sent: Monday, November 08, 2010 8:34 AM
To: Shariq Saeed® ¿¿¿¿ ¿¿¿¿
Subject: Undeliverable: RE: A Business Model


Delivery has failed to these recipients or distribution lists:

HASSAN SAEED
An error occurred while trying to deliver this message to the recipient's e-mail address. Microsoft Exchange will not try to redeliver this message for you. Please try resending this message, or provide the following diagnostic text to your system administrator.

The following organization rejected your message: bay0-mc2-f12.Bay0.hotmail.com.

  _____  

Sent by Microsoft Exchange Server 2007







Diagnostic information for administrators:

Generating server: exchange2007.aayanleasing.loc

hassanz84@hotmail.com
bay0-mc2-f12.Bay0.hotmail.com #550 SC-002 Unfortunately, messages from 86.51.14.82 weren't sent. Please contact your Internet service provider since part of their network is on our block list. You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. ##

Original message headers:

Received: from exchange2007.aayanleasing.loc ([192.168.1.10]) by
 exchange2007.aayanleasing.loc ([192.168.1.10]) with mapi; Mon, 8 Nov 2010
 08:34:25 +0300
From: =?windows-1256?Q?Shariq_Saeed=AE_____=D4=C7=D1=DE_=D3=DA=ED=CF?=
      <ssaeed@aayanleasing.com>
To: HASSAN SAEED <hassanz84@hotmail.com>
Date: Mon, 8 Nov 2010 08:34:23 +0300
Subject: RE: A Business Model
Thread-Topic: A Business Model
Thread-Index: Act/BfgtudxoPeKeRHWsIMFgkn+/rgAAJmbw
Message-ID: <514B05B0B698B04EB28F8909BE36B39F1CDE87938B@exchange2007.aayanleasing.loc>
References: <BAY137-W1BDCBBE350C42EBDF0361BF4F0@phx.gbl>
In-Reply-To: <BAY137-W1BDCBBE350C42EBDF0361BF4F0@phx.gbl>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach: yes
X-MS-TNEF-Correlator:
acceptlanguage: en-US
Content-Type: multipart/related;
      boundary="_004_514B05B0B698B04EB28F8909BE36B39F1CDE87938Bexchange2007a_";
      type="multipart/alternative"
MIME-Version: 1.0