Mail delivery failed: returning message to sender

Hello, We are having issues on our server sending mail to certain people, we will get the below error message. However if i send the same address an email from my gmail they get it no problem. Any ideas? This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: ****@****.in retry time not reached for any host after a long failure period ------ This is a copy of the message, including all the headers. ------ Return-path: <****@****.com> Received: from gw.****.com ([89.****.****.****]:16359 helo=[127.0.0.1]) by alpha.****.com with esmtpsa (TLSv1:DHE-RSA-AES128-SHA:128) (Exim 4.82) (envelope-from ) id 1X2dc8-00020k-3r for ****@****.in; Thu, 03 Jul 2014 10:47:36 +0100 Message-ID: <53B526B8.1030205@****.com> Date: Thu, 03 Jul 2014 10:47:36 +0100 From: Stephen Leonard User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: ****@****.in Subject: Test JHS Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Antivirus: avast! (VPS 140702-1, 02/07/2014), Outbound message X-Antivirus-Status: Clean ****