Share via

Add-in is not working with desktop outlook application for the shared-mailbox

Rajnesh Rathod 0 Reputation points
2025-08-25T06:36:33.0066667+00:00

Hello,

We are facing an issue with our Outlook add-in after migrating from EWS to Microsoft Graph API using Nested Authentication.

On Windows Outlook desktop application, the add-in is not visible for the shared mailbox.

On Mac Outlook desktop application, the add-in is visible but grayed out and cannot be accessed for the shared mailbox.

On the primary mailbox, the add-in works as expected without any issues.

This problem is specifically impacting shared mailboxes and has only been observed since the migration to Graph API.

Outlook | Windows | Classic Outlook for Windows | For business
0 comments

1 answer

Sort by: Most helpful
Most helpful Newest Oldest
  1. Jayden-P 6,120 Reputation points Microsoft External Staff Moderator
    2025-08-25T10:20:57.4666667+00:00

    Hi Rajnesh Rathod

    Thank you for posting your question in the Microsoft Q&A forum.

    To assist you better, I will need more information.

    Do you meet this issue in Outlook Web? (Open another mailbox tab)

    Can you please check if you meet the minimum requirement for Classic Outlook and Outlook for Mac?

    User's image

    What kind of add-ins are you using?

    User's image

    Please also check your add-in's permission and manifest. User's image

    User's image

    You can find more details at Implement shared folders and shared mailbox scenarios in an Outlook add-in - Office Add-ins | Microsoft Learn

    I also found a case that quite similar to your Add-ins not showing on shared mailbox - Microsoft Q&A

    Please give it a check.

Your answer

Answers can be marked as Accepted Answers by the question author, which helps users to know the answer solved the author's problem.