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Hi All,
Here I'm having an issue with Proxy address,
We are having internal users with upn@mydomain.com and external user with partner.upn@mydomain.com
Let's take an example for partner account: partner.uday@mydomain.com
When a user sends mail to uday@mydoamin.com instead of partner.uday@mydomain.com these mails need to be rejected because there is no user called uday@mydomain.com
But instead of getting the getting rejected these mails are delivered to partner.uday@mydomain.com,
I had searched the users AD proxy address and uday@mydoamin.com is nowhere added to the user.
We had checked the rules fs there is any rule that forwards messages from uday@mydomain.com to partner.uday@mydomain.com but there is no transport rule for this condition.
This is happing for all the partner accounts.
Can someone help me to sort it out.
@DundiAkhil-3404
First, you could use command below to check on your Exchange server, check whether this emails address exist on your Exchange server.
Get-Mailbox -ResultSize unlimited | where{$_.EmailAddresses -match "xyz.@company.com"}
Get-Contact | where{$_.WindowsEmailAddress -match "xyz.@company.com"}
Get-MailContact | where{$_.ExternalEmailAddress -match "xyz.@company.com"}
Then I want to confirm with you that:
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Hi KuleXU,
Thakns for your response and here is the output for the commands,
Here is the message trace result and it is sowing delivered here
And this is the reply i got from postmaster-undelivery Message
We create Active directory object and Snnc it it to cloud, We follow same process for the external users as our internal, but these are added in to seperate OU in AD and we add PARTNER as extra to their SMTP in additional to normal users. 2: /api/attachments/253265-image.png?platform=QnA
We use Symantec Gate way here in our environment and the mail was sent by user@keyman .com to "teppo.siivonnen@keyman .com" and "kiran.reddy@keyman .com",
But actually the SMTP are Patner.teppo.siivonnen@keyman .com and Partner.kiran.reddy@keyman .com
And for kiran.reddy@keyman .com the mail which was sent is shown delivered in message trace but actually it was not delivered to user and got that NDR which was shared above.
For teppo.siivonnen@keyman .com the mail got delivered to Partner.teppo.siivonnen@keyman .com.
Here I checked the PS commands which was shared by you and attached the same in above comment.
I'm really confused how the mails sent to teppo.siivonnen@keyman .com are getting delivered to Partner.teppo.siivonnen@keyman .com
From the picture above, we can know that the "teppo.siivonnen@keyman .com" is a proxy address for the Partner.teppo.siivonnen.
I guess this phenomenon caused by email address misconfigure.
I would suggest you login Exchange online admin center (https://admin.exchange.microsoft.com/#/mailboxes), then check on the Partner.teppo.siivonnen mailbox and teppo.siivonnen mailbox.
Check whether email address is misconfigured for them.
I also noticed the on the below picture, the name for "teppo.siivonnen@keyman .com" is "teppo siivonnen", but the alias is "Partner.teppo.siivonnen".
Hi ,
Thanks for your time and response,
Here is the Email address list for the user
Partner.teppo.siivonnen@keyman .com
Partner.teppo.siivonnen@keyman .onmicrosoft.com
partner.teppo.siivonen@keyman .mail.onmicrosoft.com
As you noticed the on the below picture, the name for "teppo.siivonnen@keyman .com" is "teppo siivonnen", but the alias is "Partner.teppo.siivonnen".
I'm really getting confused with this, Where as i can't find the SMTP teppo.siivonnen@keyman .com any where from Exchange and AD attributes but still the mail got delivered to patner.teppo.siivonnen@keyman .com
You could use command below to double check about it:
Get-Mailbox -ResultSize unlimited | where{$_.EmailAddresses -match "xyz.@company.com"} | select Identity,*address*
Hi I tried that command here is the output:
I searched for xyz@mathieu.company .com and got results of partner.xyz@mathieu.company .com
Is there any link between these two now?
If there is link then could you please suggest me how to remove it.
Next step, I would suggest you have a check about transport rule, check whether there exists a rule which redirect emails from for this mailbox.
You can also have a check about the "Email forwarding" on this mailbox from Exchange online admin center, check whether "Email forwarding" configured for this mailbox.
Thanks for your response,
An update for this, we are facing this issue with all partner accounts
I had picked some partner accounts and sent messages to them by using xyz@keyman .com but they gets delivered to Partner.xyz@keyman .com
I had a check with the transport rule and i can't find any rule which redirects mail
And Email forwarding is off for the org and also i checked for invidual users they are turned off
Hello @KyleXu-MSFT ,
I found these Security restrictions in My connector
Always use Transport Layer Security ‎(TLS)‎ and connect only if the recipient’s email server certificate is issued by a trusted certificate authority ‎(CA)‎, and the subject name matches this domain: ‎autodiscover.mydomain.com‎
Is this the reason for partner.xyz@mydomain.com is receiving mails sent to xyz@mydomain.com?
You could try to disable this one, then check whether emails could be sent to the correct mailbox.
I also suggest you use the "Get-MessageTrace" command to check whether emails redirected by Exchange online side:
Get-MessageTrace -SenderAddress john@contoso.com -StartDate 11/1/2022 -EndDate 11/9/2022
Hello @KyleXu-MSFT
I will give it a try with disabling the autodiscover.mydomain.com in the non-business hours and update you with the output
And FYI Here are results of the message trace (Which were sent earlier without disabling the autodiscover.mydomain.com in the connector)
Mail sent to xyz@keyman .com which was delivered to partner.xyz@keyman .com
@DundiAkhil-3404
Here is the detailed information about this event:
Whether is this mailbox has a local AD object? If so, have a check about the ‘mail’, 'userPrincipalName', 'targetAddress' and 'proxyAddresses' attribute on this AD object.
Hello @KyleXu-MSFT
Yes the user mailbox is having AD object
Please have a look in to these and everywhere I can see partner.xyz@mydomain.com only
@DundiAkhil-3404
Are those attributes is used for the xyz@mydomain.com?
If so, I think this AD account and mailbox is misconfigured, it is suggested to back up mailbox data, then delete mailbox and AD account to create a new one.
No these attributes are for partner.xyz@mydomain.com only, These are correct one for that particular external/partner account.
But the issue is mails are getting delivered to these partner.xyz@mydomain.com when user send mail to xyz@mydomain.com
Hello @KyleXu-MSFT
Is there any suggestion for this issue?
What about the configuration on the xyz@mydomain.com AD account? We should check on the "xyz@mydomain.com" for check whether emails redirect by this account.
@KyleXu-MSFT
There is no account with xyz@mydomain.com
And I had shared the proxy address of the partner.xyz@mydomain.com in above comments.
I raised MS ticket for this issue, and they said this is because of CMT is enabled, and they suggested to turn it off.
And I have one concern does it make any other consequences when I turn the CMT off