Jan 23 2017 09:07 AM
Since about a month we cannot relay email from our IIS SMTP Relay to Office 365. This has worked for a long time, therefore I do not get why it is not working anymore. The account used is still active and Iám able to sign-in with the account. I've even completely reinstalled and reconfigured the SMTP relay role in IIS following this procedure:
I'm getting the following warning in the eventvwr:
Message delivery to the host '40.97.153.170' failed while delivering to the remote domain '##########.COM' for the following reason: The remote SMTP service rejected AUTH negotiation.
Hope you guys can help me out here.
Jan 23 2017 02:17 PM
Hello, Ronald,
You might want to checkout the article below, it has some additional troubleshooting and configuration guidance.
Setting up multifunction device or application to send email using Office 365
https://technet.microsoft.com/en-us/library/Dn554323(v=EXCHG.150).aspx
Let me know if it helps.
Nick
Jan 23 2017 04:28 PM
How is the handshake protocol being implemented? Kerb? CHAP?, etc....FS?
Jan 23 2017 11:13 PM - edited Jan 23 2017 11:15 PM
Hi, there have been made som changes starting 2017
Jan 24 2017 05:33 AM
Hi,
We have the same message.
Some mails wont get thru i thougt it was problem on the other side.
last week we had some problems .
we have a hybrid setup i think is setup right.
how come some mails work and others not ?
Jan 24 2017 07:03 AM
Note that this will be forced only from 1st February, so the root cause is definitely different here.
Jan 24 2017 07:10 AM
@Daniel Lentz wrote:Hi, there have been made som changes starting 2017
Be sure to read the scenarios very carefully as it doesn't apply to all IIS SMTP Relay setups.
Apr 23 2019 11:41 AM
Verify you are not using "Integrated Windows Authentication" and you are using "Basic Authentication" for Outbound Security. Also the "Domain Name" should not match your Email Domain since you want to email to send via the Smart Host.
Mar 26 2021 07:33 AM
Hi, this is an old post but I got this same issue. I had to enable the SMTP Auth option at the mailbox level, on Office 365:
Mar 30 2021 09:35 AM