Emails bouncing back

Few mails are bouncing back with undelivered notification. below is the content of one email that bounced back. I checked reverse DNS entry. Your help is highly appreciated.




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: cgpfe1.batelco.com.bh.

  _____  

Sent by Microsoft Exchange Server 2007







Diagnostic information for administrators:

Generating server: uopmail.uopkt.com

devlab@prisma.com.bh
cgpfe1.batelco.com.bh #591 devlab@prisma.com.bh your host [168.187.83.138] is blacklisted by bl.spamcop.net. No mail will be accepted ##

Original message headers:

Received: from uopmail.uopkt.com ([192.168.0.204]) by uopmail.uopkt.com
 ([192.168.0.204]) with mapi; Wed, 25 Mar 2009 10:12:54 +0300
From: Ashok Kumar <marketing@uopkt.com>
To: Krishna Mohan <devlab@prisma.com.bh>
Date: Wed, 25 Mar 2009 10:12:51 +0300
Subject: The sun will never set on the petro-economies, just covered by
 clouds
Thread-Topic: The sun will never set on the petro-economies, just covered by
 clouds
Thread-Index: AcmtGRwZ2efdY0DST3qnJ8uDAU6V9g==
Message-ID: <9264FA75B8147B4FA4B76B2A52FE718C431F5C85CC@uopmail.uopkt.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
acceptlanguage: en-US
Content-Type: multipart/alternative;
      boundary="_000_9264FA75B8147B4FA4B76B2A52FE718C431F5C85CCuopmailuopktc_"
MIME-Version: 1.0