HiOnce in a while some of our users are getting below NDR while sending mails to external users. The following recipient(s) cannot be reached: MusafOtaibi on 21/10/09 11:41 You do not have permission to send to this recipient. For assistance, contact your system administrator. <ExchMAIL2.MYCOMPANY #5.7.1>This NDR is generating from BE server and the recipient is in external domain. Also all external mails are forwarded to smart host in our environment. Can anyone help us to resolve this issueThanks in advanceRegardsLalServer Engineer

Please Go through below article and see if it helps you http://searchexchange.techtarget.com/generic/0,295582,sid43_gci1222337,00.htmlVinod |CCNA|MCSE 2003 +Messaging|MCTS|ITIL V3|

Is this happening with some users or all the users ?Check this out http://forums.msexchange.org/You_do_not_have_permission_to_send_to_this_recipient/m_180147400/tm.htmhttp://social.technet.microsoft.com/Forums/en/exchangesvrdeploy/thread/7f0b3dab-0e1c-4998-b87c-2be0da34b108Raj

Hi,This issue may occur if the any securiy policy block your sender or Exchange server itself doesn't allow the sender to send the email.Please first confirm whether any error message come up in the Application event log. Then enable the Message Tracking log and check which phase did this issue occurred. You can also send it to me at allensyr2003@hotmail.comAdditionally, the link which provided by Vinod is very useful since several possbile causes are listed there. You can refer to it.ThanksAllen

Hi AllenWe checked in event logs and not found any errors, also we tracked the mail and I can see that NDR genrated from BE server itself, but 2nd time it went through. This is happend only a few times and we are not getting any more complaints now.Thanks for your supportReagrdsLalServer Engineer

Hi,OK, you can monitor this issue. If the issue comes back, please let me know.ThanksAllen

If you want to dig further into this issue you can try bouncing the diagnostics logging on Transport component of the server which generates this NDR and see what error code is generated. Raising dianostics logging to Medium level should be able to illustrate the problem.Typically, 5.7.1 is related to realying or the permissions. If the problem persists you cantry dumping the user properties using LDP.exe and compare it with a normal user whose mailbox doesnt generate any NDR. If this is just one user I would prefer going with the other method than simply increasing the diagnostics logging and flood my application log. Do keep posted about it.Milind Naphade | MCTS:M (Exchange 2007 and 2010) | http://www.msexchangegeek.com