Microsoft Copilot | Microsoft 365 Copilot | Development
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Using Copilot on a Delegate Mailbox
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Jacobs, Mark
0
Reputation points
Microsoft recently announced support for users assigned "full delegate access" to use Copilot to search the contents of another user's mailbox. The article noted that:
My QUESTION is: What does "full delegate access" mean, specifically?
- Can the mailbox owner simply go to File > Account Settings > Delegate Access and assign another person EDITOR (or) AUTHOR (or) REVIEWER (or) CONTRIBUTOR rights? Do any of these permission levels equal "full delegate access"?
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- If the permissions available under File > Account Settings > Delegate Access do NOT give the delegate "full delegate access"-- what is the SPECIFIC permission level within Exchange that a delegate would need? Is it "Full Mailbox Access (FMA)"?
Thank you for any assistance in clarifying this issue.
Microsoft Copilot | Microsoft 365 Copilot | Development
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Yasser Mohamed 0 Reputation points2025-12-18T16:27:13.56+00:00 did you find an answer to this question?
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Jacobs, Mark 0 Reputation points
2025-12-18T16:50:55.4833333+00:00 @Yasser Mohamed YES. The answer is that granting Full Mailbox Access (FMA) via Exchange is the ONLY permission model fully compatible when a user wants to use Copilot to search a mailbox as a delegate.
NOTE 1: Even with FMA, users may still experience incomplete or negative search results if they reference a mailbox using Context IQ (e.g., /Smith, John) instead of the full email address (e.g., john.smith@microsoft.com) in the prompt. Until this is resolved, instruct users to always use the full email address followed by the word “mailbox” when referencing a mailbox in a Copilot prompt. (per this article)
NOTE 2: FMA grants access to all mailbox content, including private items. The mailbox owner should carefully weigh the trade-off between providing broad access and maintaining privacy.
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Yasser Mohamed 0 Reputation points
2025-12-18T20:12:05.8133333+00:00 Thank you for sharing, very helpful!
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