Get-EXOMailboxPermission

This cmdlet is available only in the Exchange Online PowerShell module. For more information, see About the Exchange Online PowerShell module.

Use the Get-EXOMailboxPermission cmdlet to retrieve permissions on a mailbox.

For information about the parameter sets in the Syntax section below, see Exchange cmdlet syntax.

Syntax

Get-EXOMailboxPermission
   [-ResultSize <Unlimited>]
   [<CommonParameters>]
Get-EXOMailboxPermission
   [-ExternalDirectoryObjectId <Guid>]
   [-Identity <String>]
   [-Owner]
   [-PrimarySmtpAddress <String>]
   [-ResultSize <Unlimited>]
   [-SoftDeletedMailbox]
   [-User <String>]
   [-UserPrincipalName <String>]
   [<CommonParameters>]

Description

The output of this cmdlet shows the following information:

  • Identity: The mailbox in question.
  • User: The security principal (user, security group, Exchange management role group, etc.) that has permission to the mailbox.
  • AccessRights: The permission that the security principal has on the mailbox. The available values are ChangeOwner (change the owner of the mailbox), ChangePermission (change the permissions on the mailbox), DeleteItem (delete the mailbox), ExternalAccount (indicates the account isn't in the same domain), FullAccess (open the mailbox, access its contents, but can't send mail) and ReadPermission (read the permissions on the mailbox). Whether the permissions are allowed or denied is indicated in the Deny column.
  • IsInherited: Whether the permission is inherited (True) or directly assigned to the mailbox (False). Permissions are inherited from the mailbox database and/or Active Directory. Typically, directly assigned permissions override inherited permissions.
  • Deny: Whether the permission is allowed (False) or denied (True). Typically, deny permissions override allow permissions.

By default, the following permissions are assigned to user mailboxes:

  • FullAccess and ReadPermission are directly assigned to NT AUTHORITY\SELF. This entry gives a user permission to their own mailbox.
  • FullAccess is denied to Administrator, Domain Admins, Enterprise Admins and Organization Management. These inherited permissions prevent these users and group members from opening other users' mailboxes.
  • ChangeOwner, ChangePermission, DeleteItem, and ReadPermission are allowed for Administrator, Domain Admins, Enterprise Admins and Organization Management. Note that these inherited permission entries also appear to allow FullAccess. However, these users and groups do not have FullAccess to the mailbox because the inherited Deny permission entries override the inherited Allow permission entries.
  • FullAccess is inherited by NT AUTHORITY\SYSTEM and ReadPermission is inherited by NT AUTHORITY\NETWORK.
  • FullAccess and ReadPermission are inherited by Exchange Servers, ChangeOwner, ChangePermission, DeleteItem, and ReadPermission are inherited by Exchange Trusted Subsystem and ReadPermission is inherited by Managed Availability Servers.

By default, other security groups and role groups inherit permissions to mailboxes based on their location (on-premises Exchange or Microsoft 365).

Examples

Example 1

Get-EXOMailboxPermission -Identity john@contoso.com

This example return the permission the user has on mailboxes

Parameters

-ExternalDirectoryObjectId

The ExternalDirectoryObjectId parameter identifies the mailbox that you want to view by the ObjectId in Microsoft Entra ID.

You can't use this parameter with the Identity, PrimarySmtpAddress, or UserPrincipalName parameters.

Type:Guid
Position:Named
Default value:None
Required:False
Accept pipeline input:True
Accept wildcard characters:False
Applies to:Exchange Online

-Identity

The Identity parameter specifies the mailbox you want to view. For the best performance, we recommend using the user ID or user principal name (UPN) to identify the mailbox.

Otherwise, you can use any value that uniquely identifies the mailbox. For example:

  • Name
  • Alias
  • Distinguished name (DN)
  • LegacyExchangeDN
  • SamAccountName

You can't use this parameter with the ExternalDirectoryObjectId, PrimarySmtpAddress, or UserPrincipalName parameters.

Type:String
Position:Named
Default value:None
Required:False
Accept pipeline input:True
Accept wildcard characters:False
Applies to:Exchange Online

-Owner

The Owner switch returns the owner information for the mailbox that's specified by the Identity parameter. You don't need to specify a value with this switch.

Type:SwitchParameter
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False
Applies to:Exchange Online

-PrimarySmtpAddress

The PrimarySmtpAddress identifies the mailbox that you want to view by primary SMTP email address (for example, navin@contoso.com).

You can't use this parameter with the ExternalDirectoryObjectId, Identity, or UserPrincipalName parameters.

Type:String
Position:Named
Default value:None
Required:False
Accept pipeline input:True
Accept wildcard characters:False
Applies to:Exchange Online

-ResultSize

The ResultSize parameter specifies the maximum number of results to return. If you want to return all requests that match the query, use unlimited for the value of this parameter. The default value is 1000.

Type:Unlimited
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False
Applies to:Exchange Online

-SoftDeletedMailbox

The SoftDeletedMailbox switch is required to return soft-deleted mailboxes in the results. You don't need to specify a value with this switch.

Soft-deleted mailboxes are deleted mailboxes that are still recoverable.

Type:SwitchParameter
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False
Applies to:Exchange Online

-User

The User parameter returns information about the user who has permissions to the mailbox specified by the Identity parameter.

The user that you specify for this parameter must be a user or security group (a security principal that can have permissions assigned). You can use any value that uniquely identifies the user. For example:

  • Name
  • Distinguished name (DN)
  • Canonical DN
  • GUID

Note: Currently, the value that you provide for this parameter is case sensitive.

Type:String
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False
Applies to:Exchange Online

-UserPrincipalName

The UserPrincipalName parameter identifies the mailbox that you want to view by UPN (for example, navin@contoso.onmicrosoft.com).

You can't use this parameter with the ExternalDirectoryObjectId, Identity, or PrimarySmtpAddress parameters.

Type:String
Position:Named
Default value:None
Required:False
Accept pipeline input:True
Accept wildcard characters:False
Applies to:Exchange Online