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smtp;550 5.7.1 Client does not have permissions to send as this sender. NDR in bad mail folder. Please help!

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I am trying to use office 365 as an SMTP relay for an application server. I have configured the SMTP server on the local application service to connect to the 365 server as recommended. Normal emails will relay without an issue. I can send/receivce email in the OWA without issue, inside and outside the domain. 

the problem I am having is that application is configured to "send email on behalf of another user".  when I trigger an email notification on the application I am getting an NDR in the bad mail folder. it says:

Final-Recipient: rfc822;
Action: failed
Status: 5.7.1
Diagnostic-Code: smtp;550 5.7.1 Client does not have permissions to send as this sender

Content-Type: message/rfc822

Received: from MYAPPSERVER ([]) by with Microsoft SMTPSVC(7.5.7601.17514);
Mon, 8 Oct 2012 22:31:24 -0500
MIME-Version: 1.0
Date: 9 Oct 2012 03:31:24 +0000
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: base64
Message-ID: <>

what I have done:

I have added as an external contact in 365 online and then ran the following power shell command:

Add-RecipientPermission <identity> -AccessRights SendAs -Trustee <user>

which was: 

Add-RecipientPermission -AccessRights SendAs -Trustee

I am still getting the same error. Am I missing something? the power shell command completed without errors. the user should have permission to send email on behalf of

what is the problem?

All Replies
  • Hi ccrump,

    According to your description, I understand that you want to use Office 365 as an SMTP relay for an application server and you can send and receive emails well in OWA, however when you send emails in Outlook desktop client in Outlook desktop client, you received the NDR.

    Given this situation, I'd like to suggest you do the following steps:
    1.Create a distribution group and make the email address with your Office 365 domain name or your custom domain which added to your Office 365 account as the name of the distribution group so that you can receive emails sent to these addresses( But not send from these addresses), then you can add other email addresses to the distribution group.
    To create a new distribution group, please refer to:
    2.Give SendAs permission of the distribution group to your account.
    3.Send emails in your account and make the distribution address as from address to check whether you can receive the same NDR.

    Vivian Wang


  • Hi ccrump,

    Just checking in to see whether the information was helpful. Please let us know whether you would like additional help.

    Vivian Wang

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