Duo O365 SSO and Outlook



I have successfully federated my email domain to the Duo DAG and everything but Outlook seems to be working. Looking at the DAG log while attempting to either re-connect to a previously configured Outlook, or creating a new Outlook profile - nothing is ever getting logged at all. It continuously prompts for the password. Portal Logins, Smartphone account setups and logins are working perfectly, I can see log entries when doing so. Has anyone ever seen this particular issue or have any good troubleshooting measures I can take here?



We have a number of articles about O365 client interactions after federation with Duo. I suggest you start with Why is my Outlook client not showing a 2FA prompt when Office 365 is protected by Duo? and then explore other articles on this topic.

If you are unable to resolve the issue, contact Duo Support.


Have you enabled modern authentication in Office 365? If you haven’t, Outlook will not know how to use Duo and will continue to try basic auth and never try to interact with the DAG.