OAuth setup on DNN 10.1.2

[datafastlr]

I set up the OAuth Exchange Online SMTP settings in DNN 10.1.2 and verified "Your OAuth provider's configuration has been completed."

However, when I test the SMTP settings, I get the following error:
There is a problem with the configuration of your SMTP Server. Mail was not sent. 535: 5.7.3 Authentication unsuccessful [MN0PR02CA0003.namprd02.prod.outlook.com 2025-10-17T16:03:50.567Z 08DE0D6838535D6C]

I guess I'm confused as to why the configuration was successful, but the mail can't be sent.

Any help appreciated.

Regards,
Larry R

[valadas]

I don't use that but a few people have documented some of it, maybe you find some clues there https://docs.dnncommunity.org/content/tutorials/server/smtp-servers/set-up-oauth-microsoft-365/index.html