# Exchange Online (Graph API): Access Denied for Shared Mailbox despite verified permissions **URL:** \ **Category:** Support\ **Created:** [August 25, 2026, 2:43pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772 "2026-08-25T14:43:54Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![davidMF98](https://community.easymorph.com/letter_avatar_proxy/v4/letter/d/a9adbd/32.png) [@davidMF98](https://community.easymorph.com/u/davidMF98)\ **Post date:** [August 25, 2026, 2:43pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/1 "2026-08-25T14:43:54Z")
Hello EasyMorph Team, After upgrading to EasyMorph Hub and transitioning our Exchange Online connectors to the new Graph API architecture, I am receiving an "Access Denied" error when trying to read specific shared mailboxes. Strangely, the connector works perfectly for two other shared mailboxes, but consistently fails on this one. I have tested this on both EasyMorph Desktop and Hub, yielding the same error. **Troubleshooting already completed:** - **Azure AD Permissions:** The "EasyMorph for Exchange Online" app registration has `Mail.ReadWrite.Shared` (and other required scopes) granted, and Global Admin consent is confirmed. - **Exchange Delegation:** The user account authenticating the connector has explicit "Full Access" and "Send As" delegation for the target shared mailbox. - **Graph Explorer Test (Successful):** I logged into the official Microsoft Graph Explorer with the exact same user account used in EasyMorph. I successfully executed the following call: `[``https://graph.microsoft.com/v1.0/users/SharedMailbox@contoso.com/messages?$top=1``](``https://graph.microsoft.com/v1.0/users/SharedMailbox@contoso.com/messages?$top=1``)`. Because Graph Explorer successfully retrieves the mail but the EasyMorph connector gets Access Denied for the same mailbox and user, the issue seems isolated to the connector's execution. Are there known issues with the Graph API connector handling specific shared mailbox configurations, or extra parameters required for mailboxes that might be routing differently? Thank you! ---
**Author:** ![serhii](https://community.easymorph.com/letter_avatar_proxy/v4/letter/s/df788c/32.png) [@serhii](https://community.easymorph.com/u/serhii)\ **Post date:** [August 25, 2026, 8:45pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/2 "2026-08-25T20:45:52Z")
Hi, @davidMF98 We are looking into the issue and will keep you updated. ---
**Author:** ![davidMF98](https://community.easymorph.com/letter_avatar_proxy/v4/letter/d/a9adbd/32.png) [@davidMF98](https://community.easymorph.com/u/davidMF98)\ **Post date:** [September 7, 2026, 7:24am UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/3 "2026-09-07T07:24:29Z")
Hi @serhii , Are there any updates for this subject? Regards, David ---
**Author:** ![serhii](https://community.easymorph.com/letter_avatar_proxy/v4/letter/s/df788c/32.png) [@serhii](https://community.easymorph.com/u/serhii)\ **Post date:** [September 7, 2026, 1:53pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/4 "2026-09-07T13:53:54Z")
Hi @davidMF98 We’re still investigating the issue and working on identifying the root cause and a solution. I’ll keep you updated as soon as we have any further information. Best regards, Serhii ---
**Author:** ![serhii](https://community.easymorph.com/letter_avatar_proxy/v4/letter/s/df788c/32.png) [@serhii](https://community.easymorph.com/u/serhii)\ **Post date:** [September 8, 2026, 5:53pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/5 "2026-09-08T17:53:36Z")
Hi @davidMF98 We'd like to ask you to run a few additional Graph API requests so we can narrow down where the issue occurs. **1. Get a message ID** In Graph Explorer, run the following request, adding this header: Prefer: IdType="ImmutableId" `GET ``https://graph.microsoft.com/v1.0/users/problem@contoso.com/mailFolders/inbox/messages?$top=1&$select=id` Please replace [problem@contoso.com](mailto:problem@contoso.com) with the email address of the shared mailbox that causes the problem. You should get a response containing something similar to: `{ "value": [{ "id": "AAkALgAAAA..." }] }` We only need the ID from this response for the next step. **2. Translate the message ID** Take the ID from step 1 and use it in the following request: `POST ``https://graph.microsoft.com/v1.0/users/problem@contoso.com/translateExchangeIds` with this request body: `{ "inputIds": ["YOUR ID FROM STEP 1"], "sourceIdType": "restImmutableEntryId", "targetIdType": "ewsId" }` Please let us know whether this request completes successfully or returns an error. **3. Retrieve more messages** If step 2 completes successfully, please run: `GET ``https://graph.microsoft.com/v1.0/users/problem@contoso.com/mailFolders/inbox/messages?$top=250&$select=id` Again, please replace [problem@contoso.com](mailto:problem@contoso.com) with the affected mailbox. If all requests complete successfully without errors, there is nothing else we need from you at this point. We will continue investigating the issue on our side. If any of the requests fail, please send us only the HTTP status/error code. We do not need any mailbox contents, message IDs, email addresses, or other personal data. ---
**Author:** ![davidMF98](https://community.easymorph.com/letter_avatar_proxy/v4/letter/d/a9adbd/32.png) [@davidMF98](https://community.easymorph.com/u/davidMF98)\ **Post date:** [September 11, 2026, 6:02am UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/6 "2026-09-11T06:02:59Z")
Hi, Did the tests and they were all successful. Thank you, David ---
**Author:** ![serhii](https://community.easymorph.com/letter_avatar_proxy/v4/letter/s/df788c/32.png) [@serhii](https://community.easymorph.com/u/serhii)\ **Post date:** [September 11, 2026, 1:18pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/7 "2026-09-11T13:18:29Z")
Hi, Thank you for running the tests and confirming that everything completed successfully. We’re continuing to investigate the issue on our side and will keep you updated as soon as we have any further information. Best regards, Serhii ---
**Author:** ![oripert](https://community.easymorph.com/letter_avatar_proxy/v4/letter/o/919ad9/32.png) [@oripert](https://community.easymorph.com/u/oripert)\ **Post date:** [September 28, 2026, 12:16pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/8 "2026-09-28T12:16:52Z")
Hello, I am facing the same issue. Except that I have an error message at step 2 : ![image](https://community.easymorph.com/uploads/default/original/2X/3/39a1069bd054799e3f8d675bd02cd6f1fe635e6b.png) But step 3 is working...I can also retrieve the subject. We are using version 6.1.0.10. Any progress on the resolution ? Thanks in advance !! ---
**Author:** ![oripert](https://community.easymorph.com/letter_avatar_proxy/v4/letter/o/919ad9/32.png) [@oripert](https://community.easymorph.com/u/oripert)\ **Post date:** [September 28, 2026, 12:28pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/9 "2026-09-28T12:28:41Z")
After some doc readings and tests, Step 2 works with restId as sourceIdType. 😅 ---
**Author:** ![serhii](https://community.easymorph.com/letter_avatar_proxy/v4/letter/s/df788c/32.png) [@serhii](https://community.easymorph.com/u/serhii)\ **Post date:** [September 28, 2026, 1:52pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/10 "2026-09-28T13:52:15Z")
Hi, We’re still working on the issue and haven’t resolved it yet. Thank you for the additional information and for sharing your findings. The details are very helpful and will be useful for our investigation. We’ll keep you updated as soon as we have any further information. ---
**Author:** ![oripert](https://community.easymorph.com/letter_avatar_proxy/v4/letter/o/919ad9/32.png) [@oripert](https://community.easymorph.com/u/oripert)\ **Post date:** [September 28, 2026, 2:29pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/11 "2026-09-28T14:29:37Z")
Hi, Thanks and sorry for pushing as this is critical for us and the post is opened since more than 20 days. During the migration, we used the test function on the connector to check if it was working. All good but in fact EM is not able to retrieve mails from shared mailbox. Not an access issue as EM is able to see the list of folders. There is also no error when the mailbox is empty. We have daily processing extracting emails from share mailboxes and we are now blocked. From your questions, it seems to be linked to the message ids Exchange is sending back in graph api calls which in various formats (ews, rest, rest imutable...) and it exists an http header to set the prefer format =\> Prefer: IdType="ImmutableId". This solved the step 2 of your earlier post on my side when querying with Microsoft Graph Explorer. If EM is expecting that format, adding this http header may then solve the issue. Thank you. ---
**Author:** ![serhii](https://community.easymorph.com/letter_avatar_proxy/v4/letter/s/df788c/32.png) [@serhii](https://community.easymorph.com/u/serhii)\ **Post date:** [September 29, 2026, 9:29pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/12 "2026-09-29T21:29:53Z")
Hi @davidMF98 @oripert We’ve made an update regarding the reported issue. You can download the latest version [here](https://easymorph.com/download). Please check the new version on your side and let us know if the issue has been resolved. ---
**Author:** ![oripert](https://community.easymorph.com/letter_avatar_proxy/v4/letter/o/919ad9/32.png) [@oripert](https://community.easymorph.com/u/oripert)\ **Post date:** [September 30, 2026, 6:07am UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/13 "2026-09-30T06:07:17Z")
Hi @serhii , Thanks for the update but it seems there is an issue with the installer : ![image](https://community.easymorph.com/uploads/default/original/2X/8/8f493812b0b8a5703b7523772bf44aa30e11bdab.png) The message pops up directly after running the exe. I downloaded it several times and also tried to run it as administrator but same error. Thanks ! ---
**Author:** ![Den.Onufriiev](https://community.easymorph.com/letter_avatar_proxy/v4/letter/d/a5b964/32.png) [@Den.Onufriiev](https://community.easymorph.com/u/Den.Onufriiev)\ **Post date:** [September 30, 2026, 10:10am UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/14 "2026-09-30T10:10:42Z")
Hello @oripert ! Try to extract the downloaded archive to a different folder. Best regards, Denys Onufriiev ---
**Author:** ![oripert](https://community.easymorph.com/letter_avatar_proxy/v4/letter/o/919ad9/32.png) [@oripert](https://community.easymorph.com/u/oripert)\ **Post date:** [September 30, 2026, 11:48am UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/15 "2026-09-30T11:48:12Z")
Hi @Den.Onufriiev Thanks for your hint but actually it is a policy rule in our Defender which prevents too recent binaries to be installed 😶‍🌫️ ---
**Author:** ![Den.Onufriiev](https://community.easymorph.com/letter_avatar_proxy/v4/letter/d/a5b964/32.png) [@Den.Onufriiev](https://community.easymorph.com/u/Den.Onufriiev)\ **Post date:** [September 30, 2026, 1:53pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/16 "2026-09-30T13:53:07Z")
Hi @oripert Looks like there's nothing we can do on our side. Do you know how old a binary should be for the Defender to allow it? Best regards, Denys Onufriiev ---
**Author:** ![oripert](https://community.easymorph.com/letter_avatar_proxy/v4/letter/o/919ad9/32.png) [@oripert](https://community.easymorph.com/u/oripert)\ **Post date:** [September 30, 2026, 2:08pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/17 "2026-09-30T14:08:03Z")
Hello @serhii @Den.Onufriiev We have been able to install by temporarily creating an exception. Not sure, but it seems your installer is not signed and so not trusted by Defender. Otherwise I did a new test and it is still not working : ![image](https://community.easymorph.com/uploads/default/original/2X/d/d7205857a1f80bec249352c0b5817d77f61e9c82.png) I tried on several shared mailboxes and same error. I tried on my own inbox and it works. Thanks for your support. Olivier ---
**Author:** ![olysak](https://community.easymorph.com/letter_avatar_proxy/v4/letter/o/aeb1de/32.png) [@olysak](https://community.easymorph.com/u/olysak)\ **Post date:** [September 30, 2026, 4:10pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/18 "2026-09-30T16:10:55Z")
@oripert Could you pls try a quick test - could you set the fetch limit to ![image](https://community.easymorph.com/uploads/default/original/2X/e/e5f1c398747cc6edc6b363d83869b7bbf35f8b6e.png) and rerun. Maybe this is one specific message (encrypted or unusual item type) ---
**Author:** ![oripert](https://community.easymorph.com/letter_avatar_proxy/v4/letter/o/919ad9/32.png) [@oripert](https://community.easymorph.com/u/oripert)\ **Post date:** [September 30, 2026, 5:09pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/19 "2026-09-30T17:09:24Z")
Hi @olysak No luck. I've tried on 4 shared mailboxes, different folders, parameters and always get the same error. It works only if the folder is empty. Is there a way to know on which graph api call we are getting that error ? Access is working as EM retrieves the folders correctly : ![image](https://community.easymorph.com/uploads/default/original/2X/5/5b5b7b208be860df929e8c8daaf7e62ea54dabd0.png) May it be linked to a missing permission on the azure app to retrieve the messages ? Have you also looked at that issue with the message id format ? I can do more testing if you need. Thanks Olivier ---
**Author:** ![andrew.rybka](https://community.easymorph.com/user_avatar/community.easymorph.com/andrew.rybka/32/13_2.png) [@andrew.rybka](https://community.easymorph.com/u/andrew.rybka)\ **Post date:** [September 30, 2026, 5:14pm UTC](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772/20 "2026-09-30T17:14:28Z")
Hi @oripert, > [@oripert](#): > > We have been able to install by temporarily creating an exception. Not sure, but it seems your installer is not signed and so not trusted by Defender. Both the installer and the application executable are signed. You can check it yourself: ![image](https://community.easymorph.com/uploads/default/original/2X/2/25a33ed326a06622aa0d3984c1ff9c7b55a3648f.png) ![image](https://community.easymorph.com/uploads/default/original/2X/7/718fadf22278e8b47e927ebced59f0b760b15cdd.png) [Next page](https://community.easymorph.com/t/exchange-online-graph-api-access-denied-for-shared-mailbox-despite-verified-permissions/6772.md?page=2)