Exchange Online: What mailboxes User has access to?

2024-12-30

The article describes a way how to verify user’s access rights to other people’s mailboxes.

Check who has access to a single mailbox

In order to check who has access to a single mailbox, run the following cmdlet:

Get-MailboxPermission -Identity arleta

arleta - identity of the mailbox, e.g. arleta@testova365.onmicrosoft.com

In the screenshot below you can see that user2@testova365.onmicrosoft.com has FullAccess rights on the mailbox. But how to check which and how many mailboxes user2 has access to?



Check what mailboxes a user has access to

There is no direct cmdlet, but we can loop through all the existing mailboxes and verify specific user’s rights:

$mailboxes =  Get-Mailbox -Resultsize Unlimited

foreach($mailbox in $mailboxes){
    Get-MailboxPermission -Identity $mailbox.Identity -User user2@testova365.onmicrosoft.com
    }

The AccessRights columns display the access level to each individual mailbox. User’s own mailbox will not be displayed.



Export to CSV

The report on user’s permissions can be exported to a CSV file:

foreach($mailbox in $mailboxes){
    Get-MailboxPermission -Identity $mailbox.Identity -User user2@testova365.onmicrosoft.com | export-csv c:\maiperms.csv -Append
    }



Other Languages

This article is available in other languages:

Exchange Online: Do jakich skrzynek użytkownik ma dostęp? (pl-PL)

Exchange Online: lister les boîtes aux lettres auxquelles un utilisateur a accès (fr-FR)