Adding mailboxpermission with access rights set to ReadPermission doesn't work

Hi All,

Staff member ‘employee’ needs access to mailbox ‘supervisor’ with read only rights

When I use the following command it works like a charm:
Add-MailboxPermission -Identity supervisor -User employee -AccessRights FullAccess -InheritanceType All

I can add the supervisor mailbox in the employee’s Outlook and all folders expand and are visible. However setting -AccessRights to FullAccess gives the employee too much control over the supervisor’s mailbox.

Unfortunately when I use the following command I can add the mailbox in Outlook but none of the folders expand:
Add-MailboxPermission -Identity supervisor -User employee -AccessRights ReadPermission -InheritanceType All
(Notice how -AccessRigths are set to ‘ReadPermission’ instead of ‘FullAccess’

The workaround was to use Add-MailboxFolderPermission and set the permissions to all subfolders individually.

Any insight will be much appreciated.

Hi Thomas,

when I had to grant “ReadOnly”, the below command worked, give it a try…

Add-MailboxPermission -Identity supervisor -User employee -AccessRights “Reviewer”


Hi Sok,

Thanks for responding, however that did not work. Accessright ‘reviewer’ is a valid value for Add-MailboxFolderPermission but not for Add-MailboxPermission.

See the below link which lists valid values for commandlet Add-MailboxPermission:



did you find a solution other than using Add-MailboxFolderPermission?