How to see all the mailboxes a user has access to

  • Last update on September 29th, 2023

In this article, we'll explore how to view all the mailboxes a user has access to, utilizing PowerShell and CoreView

1. Using PowerShell

You can use the PowerShell command to list all the mailboxes a user has access to in Office 365. Here are the steps to do so:

  • Open Windows PowerShell as an administrator.
  • Connect to your Office 365 account by running the following command:
Connect-ExchangeOnline -UserPrincipalName <UPN> -ShowProgress $true
  • Replace <UPN> with the user's UPN (User Principal Name).
  • Run the following command to list all the mailboxes the user has access to:
Get-Mailbox -ResultSize Unlimited | Get-MailboxPermission -User <UPN> | Where-Object { $_.AccessRights -like "*FullAccess*" } | Select-Object Identity
  • Replace <UPN> with the user's UPN (User Principal Name).
  • This command will list all the mailboxes the user has full access to. If you want to include mailboxes with different access types, you can eliminate the “Where-Object” filter.

2. Using CoreView

You can use CoreView to see all the mailboxes a user has access to. Please follow the steps below to do so:

  •  Log in to the CoreView portal
  • Under “Reports”, select “Security”, and then choose “User mailbox security”.
  • Here, apply a filter to the “Users with access” column using the user principal name of the user for whom you want to view all mailbox access. 
  • This will display all the mailboxes to which the selected user has access rights.

The “Full name”, “User principal name”, and “Primary SMTP address” columns provide details about the mailboxes the user has access to. The “Access rights” column indicates the level of access the user has to each respective mailbox.

 

Alternatively, you can access this information from the user's “User card”. 

  • Click on the user principal name in the “Active users” report to access the User Card. Alternatively, you can search for the user using the search bar located in the top menu.
  • Under “Mailbox”, click on “See details”.
  • A wizard will appear. Under the “Mailbox rights” tab, you will see all the mailboxes to which the selected user has access rights.