I'm having trouble sending email (via powershell for now) using an AD account which has been granted Send As permissions to a valid email account.  I am passing the credentials for the AD account and using the FROM address of the email account.  (This is being done from powershell usign smtp.Send.) If I change the credentials to another account it does send, so there's something different about this particular AD account.

When I attempt to send I get "the SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.1 client was not authenticated"

In the SMTP receive log I see this:

Inbound Negotiate failed because of LogonDenied  

User Name: NULL

535 5.7.3 Authentication unsuccessful

MAIL FROM:<the-valid-email-account@yyy.com>,

530 5.7.1 Client was not authenticated

What has me perplexed is that I'm doing the same thing from another machine, where I'm using an AD account to send as this same valid email account.  All I did in that case was grant the Send As permission to the AD account and it worked.

In this instance where it's not working I've also tried adding the ms-Exch-SMTP-Submit permission to the receive connector, but still cannot send email.

So I'm stumped as to what is different and needs changed in order to allow this AD account to send mail.

Thanks for any help you can provide.

• Edited by ewenix Friday, March 27, 2015 7:35 PM

Hi,

Please check the default receive connector in Exchange server. Open Properties and on the Permission Groups tab, we can check the permission and ensure that Anonymous Users is selected.

Additionally, here is a similar thread:

https://social.technet.microsoft.com/Forums/exchange/en-US/3201f365-5b74-438f-b431-f8dc194958cc/571-client-was-not-authenticated?forum=exchange2010

Regards,

Anonymous Users is NOT selected, and that is intentional.  I do not want to allow anonymous users on this receive connector.  

I'm trying to use a service account for an application to email.  The service account is not mail enabled, but I have granted it Send As permissions for a valid email account.  

Yes.   One of the errors I see is "Inbound Negotiate failed because of LogonDenied."

As I stated originally I'm passing credentials for an AD account which is not mail enabled, but has Send As permissions for a valid account.   Also as stated I'm doing this same thing for a few other accounts and it is working just fine and hitting this same receive connector.