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MSExchange Fronend transport warning

Question

Thursday, September 7, 2017 10:28 AM

Hello,

I have some warning for Exchange server2016

"Inbound authentication failed with error LogonDenied for Receive connector Default Frontend SVE01. The authentication mechanism is Ntlm. The source IP address of the client who tried to authenticate to Microsoft Exchange is [xxx.xxx.xxx.118]."

I cant understand this warning, and need I do something.

Thank You.

Kristina

All replies (6)

Thursday, September 7, 2017 11:30 AM

Hi

What event id have you received.

Regards,

Raj  Please mark as an "Answer" and do "Vote",if my contribution or answer is useful


Thursday, September 7, 2017 11:37 AM

It seems that an application or computer wants to relay messages. The sending IP address is not permitted to send emails to the connector and the mail is refused. You should get in contact with the application owner/ Computer owner of the IP address that you xxx. Ask him what he wants to do, if he needs to relay messages over your exchange you should create a relay connector and give permission to the IP address.

But if noboday is complaining you dont need to do anything ;-).


Friday, September 8, 2017 7:37 AM

Hi, Raj,

Event ID is 1035, warning.

Kristina


Friday, September 8, 2017 7:49 AM

Hi Kristina,

If it is a remote server or application, you can verify the problem with the sender as Joerg suggested. You can create a dedicated receive connector for this mail flow, adding the IP address into the connector remote network settings.

If it is an Exchange server within your organization, this could indicate an authentication issue. Here are some official articles that may help for your troubleshooting.

https://support.microsoft.com/en-us/help/979174/454-4-7-0-temporary-authentication-failure-in-a-microsoft-exchange-ser

https://blogs.technet.microsoft.com/exchangechallengeaccepted/2016/08/24/event-1035-msexchangetransport-inbound-authentication-failed-with-error-unexpectedexchangeauthblob-for-receive-connector/   

Regards,

Alex Sun

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Friday, September 8, 2017 11:36 AM

Hi

Please have a look at the previous post https://social.technet.microsoft.com/Forums/en-US/7d7fdfff-4744-44a8-a1b6-ce95731165ce/event-id-1035-authentication-failed?forum=exchangesvrsecuremessaginglegacy to finding the solution that might help you.

Regards,

Raj

Please mark as an "Answer" and do "Vote",if my contribution or answer is useful


Wednesday, September 13, 2017 2:04 AM

Hi Kristina,

Any update on your side? If yes, please let us know.

Regards,

Alex Sun

Please remember to mark the replies as an answer if they help.
If you have feedback for TechNet Subscriber Support, contact [email protected].