Not able to send mails

If you have received below mentioned messages in your log.

============================================
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

    The mail system

    ===========

    ************s@vsnl.com>: host m**.***.*et[203.200.235.142] said: 550 5.7.1 Mail
    from 122.165.*.* blocked using Trend Micro Email Reputation database.
    Please see :
    ******@vsnl.com (in reply to RCPT TO command)
    Reporting-MTA: dns; ama*.**********i.net
    X-Postfix-Queue-ID: 2382***8065
    X-Postfix-Sender: rfc822; ************@**********i.net
   Arrival-Date: Thu,  3 Jun 2010 11:22:46 +0530 (IST)
   Action: failed
   Status: 5.7.1

   ======================================================

Then your mailing system has been listed in Realtime Blockhole List (RBL). Try to remove your static ip from this site www.mail-abuse.com.