Technical Bulletin for Therefore™ users

18 September 2026
by Cono Fusco
A person writes in a notebook at a desk with a tablet keyboard, smartphone, spiral notebook, and takeaway coffee cup, using Xero to manage finances as sunlight streams through the window.

Technical Bulletin for Therefore™ users

 

Mailbox Monitoring profiles may need to be updated if using Exchange Online via Exchange Web Services.

 

Details

Microsoft is deprecating Exchange Web Services in Exchange Online on October 1, 2026. More information from Microsoft can be found here: https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/deprecation-of-ews-exchange-online

 

Therefore™ Online and On-Premises systems accessing a mailbox within Exchange Online via EWS (such as Mailbox Monitoring) will need to switch to a configuration relying on the Graph API to continue working. The option for accessing Exchange Online mailboxes via Graph API was added in Autumn of 2024 and has been available for on-premises starting with Therefore™ 2025 (v33). Affected On-Premises customers on older versions may need to update their Therefore™ systems.

 

Recommended actions

  • To configure mailbox access for Therefore™ based on Graph API, you need to create an App in Entra ID.
  • This app can access the mailbox either based on application permissions or on delegated permissions.
  • Application permissions (preferred)
    • In Entra ID grant the Mail.ReadWrite permission to the app. Note that this allows the app to read and write mail in all mailboxes.
    • (Recommended) Restrict access of the app to the specific/required mailboxes.
  • Delegated permissions
    • The administrator configures the app to access mailboxes based on a user account and thus has access only to mailboxes which this user is allowed to access.
    • The disadvantage of this approach is: if MFA is configured for this user in Entra ID, Microsoft will regularly send MFA challenges to the app, which cannot be handled by a service like Content Connector (Mailbox Monitoring). Thus, mailbox access will be blocked after a while depending on Entra ID settings.
    • Thus, MFA should be disabled for this user when connecting via the app configured above.
  • In the Therefore™ Solution Designer, Mailbox Monitoring configuration, switch to ‘Exchange (Online) – GraphAPI as App/User’ and supply access credentials.

 

Knowledge base articles are available to help guide this process. You need a Therefore™ Extranet/Support Portal account to access the links below. Contact the Therefore™ Support Team if you require further assistance.

 

 

 

 

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