Office 365 Mailbox Permissions – Viewing Mailboxes and Send-as Permissions

In Office 365 it is possible to grant users permissions to each other mailboxes so they that have the capability to view each others mailboxes or even send emails on each others behalves. There are two ways to grant Office 365 mailbox permissions – if you are logged into Microsoft Outlook as the permission granting user, you can give other users permission to view your mailbox or send emails as you. However, as an administrator, if you want to regulate this you will have to use powershell to grant these permissions. For instructions on setting up powershell, see this article. For instructions on logging in using the correct context, see this article.

Granting Office 365 Mailbox Permissions – Viewing a Mailbox

Let’s say for example you want “joe@xyzcorp.com” to be able to view the mailbox of “frank@xyzcorp.com”. Once you have powershell started up and you’re signed in as an administrator you can run this command to view the current permissions on Frank’s mailbox:

Get-MailboxPermission -Identity frank@xyzcorp.com

The next command you will run is this command to grant permission for “joe@xyzcorp.com” to view the mailbox of “frank@xyzcorp.com”.

Add-MailboxPermission -Identity frank@xyzcorp.com -User joe@xyzcorp.com -AccessRights FullAccess -InheritanceType All

Now Joe has permission to view Frank’s mailbox, but he will need to take a look from within Microsoft Outlook. To do this, he needs to navigate to File –> Open –> Other User’s Folder

Office 365 Mailbox Permissions

Once you click “Other User’s Folder” type in or select the user whose mailbox you would like to open.

View Mailbox

Now you should have full access to their mailbox. If you want to remove these permissions, run the following command:

Remove-MailboxPermission -Identity frank@xyzcorp.com -User joe@xyzcorp.com -AccessRights FullAccess -InheritanceType All

Granting Office 365 Mailbox Permissions – Send-as Permissioning

Let’s say for example you want “joe@xyzcorp.com” to be able to send emails as “helpdesk@xyzcorp.com”. Once you have powershell started up and you’re signed in as an administrator you can run this command to view the current permissions on Joe’s mailbox:

Get-RecipientPermission -Trustee joe@xyzcorp.com

The next command you will run is this command to grant permission for “joe@xyzcorp.com” to send as “helpdesk@xyzcorp.com”.

Add-RecipientPermission -Identity helpdesk@xyzcorp.com -Trustee joe@xyzcorp.com -AccessRights SendAs

Now Joe has permission to send as helpdesk’s mailbox, but he will need to set it up from within Microsoft Outlook. To do this, he needs to open a new email –> options tab –> from