Forum Discussion
Primer: Using the MFCMAPI Utility to See Inside Exchange Online Mailboxes
The MFCMAPI utility is of great help to Microsoft 365 tenant administrators who want to understand the data apps store in Exchange Online mailboxes. An on-premises mailbox stores email data, but in the cloud, Microsoft 365 apps use Exchange Online as a convenient place to store data that needs to be accessible to services like Search and eDiscovery.
https://office365itpros.com/2023/10/27/mfcmapi-utility-primer/
2 Replies
Hi Tony,
This is a great article.
Do you happen to know how a user (owner of an Exchange mailbox) can use MFCMAPI to see who has "Full Mailbox Permissions" on her/his mailbox? I know that this can be easily checked using Exchange admin tools, but in this particular case the user is not an administrator and suspects that an administrator illegally added someone with "Full Mailbox Permissions" on his/her mailbox. Since the "Full Mailbox Permissions" are store-level permissions, I assume they could be somehow seen on the very top root of the mailbox structure (when looking at in online mode).
Thanks for your hints!
I don't know where in the mailbox permissions are stored and can't find any documentation. It might be that there's a table in the database to list mailbox permissions to avoid the need to open a mailbox. It's interesting that a user can't run the Get-ExoMailboxPermission cmdlet to find the permissions for their mailbox - that indicates to me that the permissions might be stored elsewhere. Maybe VasilMichev knows.
