Enabling Hybrid Modern Authentication - Change to Window 10 Outlook client authentication flow?

Roy Esteves 41 Reputation points

We are looking to enable HMA to allow secured external access to Exchange on prem for iOS and Windows 10. iOS isn't a problem here, we understand the change to end user experience. For Windows 10, Outlook currently tunnels through a VPN to CAS. Users still leverage EAS basic auth, so we are not entirely sure how enabling HMA will change this flow.

Time and means unfortunately doesn't permit us to create a lab in which to carry out extensive testing.

Might anyone have encountered a similar challenge or provide insight as to the 'known' change in flow?


Outlook Management
Outlook Management
Outlook: A family of Microsoft email and calendar products.Management: The act or process of organizing, handling, directing or controlling something.
4,732 questions
Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
7,224 questions
0 comments No comments
{count} votes

Accepted answer
  1. Lucas Liu-MSFT 6,156 Reputation points

    Hi @Roy Esteves ,
    Regarding the changes and working methods after enabling Hybrid Modern Authentication, you can refer to: What changes when I use modern authentication?

    According to the Microsoft' official article we could know that "Once you enable HMA, a client's next login will use the new auth flow. Note that just turning on HMA won't trigger a reauthentication for any client. The clients reauthenticate based on the lifetime of the auth tokens and/or certs they have.".
    For more information: How to configure Exchange Server on-premises to use Hybrid Modern Authentication


    If the response is helpful, please click "Accept Answer" and upvote it.
    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

0 additional answers

Sort by: Most helpful