Outlook Open Another Mailbox ErrorFolderNotFound

Question

0

I am trying to open another mailbox from Outlook/Access a different email account using the Graph API. Within the exchange admin centre, I have enabled Full Access to the mailbox I am trying to access. However when I try open the account the account from Outlook using 'Open Another mailbox' I get this error:

UTC Date: 2022-01-20T04:32:42.882Z
BootResult: accessDenied
Client Version: 20220110007.08
err: Microsoft.Exchange.Data.StoreObjects.AccessDeniedException
esrc: StartupData
et: ServerError
estack: Microsoft.Mapi.MapiExceptionNoAccess
st: 500
ehk: X-OWA-Error
efe: SY6PR01CA0002
ebe: SY4PR01MB6948
ewsver: 15.20.4909.8
emsg: ErrorPermissionDenied
I've also tried doing this through the Graph Explorer using the endpoint (https://graph.microsoft.com/v1.0/users/userId/messages)But I get an error saying the folder is unavailable.

{
"error": {
"code": "ErrorFolderNotFound",
"message": "The specified folder could not be found in the store.",
"innerError": {
"date": "2022-01-20T04:41:59",
"request-id": "4f835246-029b-47af-86d5-15f5dbb52bde",
"client-request-id": "20ae4819-d85e-dd92-fe6b-14fda438e947"
}
}
}
Am I missing some permission set or something? The user I am using I believe is an admin.

Answer 1

Hi @Declan ,

Microsoft Graph Explorer app executes Microsoft Graph APIs under delegated permissions scope. When delegated permissions scope is being used, Mail.ReadBasic, Mail.Read only provides access to the authenticated user's mailbox (the only exception being those that have been explicitly shared with that user). When application permissions scope is being used, Mail.ReadBasic.All, Mail.Read provides access to any user's mailbox.

As mentioned in this documentation ,there are two scenarios where an app can get messages in another user's mail folder:

1. If the app has application permissions, or,
2. If the app has the appropriate delegated permissions from one user, and another user has shared a mail folder with that user, or, has given delegated access to that user. You can use the delegated permissions, Mail.Read.Shared or Mail.ReadWrite.Shared, to respectively read or write messages in a shared or delegated folder. See Get Outlook messages in a shared or delegated folder to help you achieving this.

As an example, Shared "Inbox" mail floder of another user : demouser@o365XXXX.onmicrosoft.com and able to access that user's "Inbox" folder emails :

GET https://graph.microsoft.com/v1.0/users/{Other User's -userId | -userPrincipalName}/mailfolders('Inbox')/messages  

Example:

GET https://graph.microsoft.com/v1.0/users/demouser@o365XXXX.onmicrosoft.com/mailfolders('Inbox')/messages  

Exchange Online Administrators can be able to grant the permissions on user's mailboxes from Exchange Online Admin Center.

Below Graph API can be used to fetch email messages of an user :

GET https://graph.microsoft.com/v1.0/users/{id | userPrincipalName}/messages  

Example :

GET https://graph.microsoft.com/v1.0/users/sampleuser@o365XXXX.onmicrosoft.com/messages  

References:
Please refer the below documenation links for more information on this:
https://learn.microsoft.com/en-us/graph/api/user-list-messages?view=graph-rest-1.0&tabs=http
https://learn.microsoft.com/en-us/graph/outlook-share-messages-folders

Hope this helps.

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