Enable Outlook Automapping for Exchange mailboxes

When a user is delegated full access rights to another mailbox, automapping will automatically add that mailbox to that user's Outlook. Automapping does this when Outlook runs a background autodiscover process and discovers that the user has been given full access to another mailbox. The user doesn't need to add the mailbox manually to Outlook and will be unable to remove the additional mailbox.

Automapping is enabled by default, but it can be disabled by running the following cmdlet:

Add-MailboxPermission TeamMailbox -User kmeyer -AccessRights FullAccess -AutoMapping $false

The cmdlet above gives user Ken Meyer full access to the TeamMailbox mailbox and disables automapping for that mailbox.

I published the Enable-AutomappingForFullAccessMailboxes.ps1 script for Exchange in the Microsoft Script Center Gallery. The script re-enables Outlook automapping on mailboxes where users have been given full access rights. It runs on Exchange 2010-2019 and Exchange Online, and must be run from the Exchange Management Shell (EMS).