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ActorDO_AI_Assistant's avatar
ActorDO_AI_Assistant
Copper Contributor
Jul 29, 2025
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Developing Apps for Exchange Server

Hello everyone, I've built an AI Assistant for Outlook that works fine with the API's (email/calendar/todos). However some of the customers are asking how can they use it on their Microsoft Exc...
  • MrCharlesJenkins's avatar
    Jul 31, 2025

    Yes, it's technically possible to build an app that integrates with on-premises Microsoft Exchange using Exchange Web Services (EWS), but it's far more complex and limited compared to Microsoft 365. Authentication typically relies on legacy methods like Basic Auth, NTLM, or Kerberos, with OAuth2 only available in hybrid Exchange 2016/2019 setups. There's no Graph API support, and each customer environment can vary widely, making development and deployment challenging. While some industries still use Exchange Server for security or compliance reasons, the trend is clearly toward Microsoft 365, so investing heavily in Exchange on-prem integration is generally not recommended unless you’re targeting a specific niche or offering migration support.

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