Nested app authentication (NAA) and deprecation of Exchange legacy tokens
Microsoft launched a new method for Outlook add-in authentication called nested app authentication (NAA) in January 2025. NAA replaced the previous authentication method, which can no longer be used.
To ensure the Signature 365 add-in continues to work, you have the following options:
- Upgrade the add-in to version 3.1 - preferred option
- Continue using your current add-in version manually granting new required permissions
We strongly recommend all customers upgrade the add-in to version 3.1
This will ensure that you are using the latest version of the add-in, and are able to take advantage of the newest updates and features.
As part of this process you will be asked to grant admin consent to two new permissions ("Maintain access to data you have given it access to" and "Sign in and read user profile"). This does not grant Signature 365 any additional access to data but is required for NAA to work.
Updating the Signature 365 modern add-in: Signature 365 Help Center
We strongly recommend all customers upgrade the add-in to version 3.1
This will ensure that you are using the latest version of the add-in, and are able to take advantage of the newest updates and features.
As part of this process you will be asked to grant admin consent to two new permissions ("Maintain access to data you have given it access to" and "Sign in and read user profile"). This does not grant Signature 365 any additional access to data but is required for NAA to work.
Updating the Signature 365 modern add-in: Signature 365 Help Center
You must manually grant admin consent to two new permissions ("Maintain access to data you have given it access to" and "Sign in and read user profile"). This does not grant Signature 365 any additional access to data, but it is required for NAA to work.
This process must be performed by a Global Admin or a user with the permission to grant the admin consent required within Microsoft 365.
Complete manual consent for your existing add-in
You can then upgrade to version 3.1 at a point to suit your company.
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