MacroView DMF and Message version 8.5 and later support Modern Authentication and enable this feature by default.
What is Modern Authentication?
When MacroView DMF or Message need to access SharePoint Online they use the Microsoft Authentication Library (MSAL) to do so. MSAL is a code library designed to make secured resources in your directory available to client applications using OAuth security tokens. MSAL works with OAuth to verify claims and to exchange tokens (rather than passwords), to grant a user access to a resource.
In the past, the authority in a transaction like this one - the server that knows how to validate user claims and issue the needed tokens - might have been a Security Token Service on-premises, or even Active Directory Federation Services. However, modern authentication centralizes that authority by using Azure AD.
MacroView DMF and Message use the OAuth 2.0 authorization code flow to securely acquire an access token that can be used to access SharePoint Online.
Enabling or disabling Modern Authentication
Once you are signed in with Modern Authentication enabled in MacroView DMF or Message, you will only be asked to sign in if you change your password, sign out or do not use DMF/Message for long periods of time.
This means you will not be prompted to authenticate to SharePoint Online each time you start Outlook, DMF Explorer or use the Open from and Save to SharePoint options in Word, Excel or PowerPoint.
To enable Modern Authentication set the below registry value to 1 (default) or to disable it set the value to 0:
What is different when Modern Authentication is enabled?
When Modern Authentication enabled, right-clicking the SharePoint Online tenant node in the tree-view will show who you are currently signed in as and allow you to sign-in with a another account.
You can also go to MacroView Options > Servers > Edit to see the current signed in user and an option to sign in as a different user for the specified SharePoint location. See the screenshot below.
When you select a library or other location on SharePoint Online (Office 365) that you don't have access to, or are not currently signed into, the top of the file list will show a gold bar warning message with an option to sign in.
More than one SharePoint Online (Office 365) tenant?
If you have multiple SharePoint Online (Office 365) tenants that are licensed to use MacroView DMF or Message, you can access them all in the same DMF session if Modern Authentication has been enabled. With Modern Authentication disabled you can access only a single SharePoint Online (Office 365) tenant.
For more information see Working with multiple SharePoint Online tenants.