Disable Exchange 2010 SP1′s Auto Shared Mailbox Mapping Feature

You may remember from my previous article "Auto-mapping shared mailboxes in Exchange 2010 SP1 with Outlook 2007 & 2010", since Exchange 2010 SP1 was released, granting a user permissions to another mailbox automatically adds the mailbox to the user's profile in both Outlook 2010 and fully patched Outlook 2007.

A few of the comments make it clear this isn't a universally-desired feature, in particular if you're an Admin and have access to a range of mailboxes (particularly system mailboxes like support addresses etc). Whilst it can be removed with ADSI edit after granting permissions, that's not a straightforward way to accomplish this.

To get round this and make it easy to add permissions without the auto-mapping I've written a straighforward script that can be used as a direct replacement to the normal Add-MailboxPermission command, Add-MailboxPermissionNoAutoMap.ps1.

Savvy Exchange Powershell coders will ask "why don't you do this using the Scripting Agent, disabling it across the board, even in Exchange Management Console".. Well that was my first thought. However, it appears that with Add-MailboxPermission the actual entries are added after the OnComplete section runs instead of before. If that get's fixed I'll certainly re-visit as it would be ideal to have a solution that allows the feature to be switched on or off on demand.

So, in the meantime, here's your drop in replacement Powershell script. It's very simple - it takes the standard parameters to the Add-MailboxPermission cmdlet and after ensuring we know what domain controller the command will act on (to ensure no replication confusion) it adds permissions the normal way, then removes the msExchDelegateListLink AD entry that has just been added.

Here's an example of it in use..


As you can see, it's very similar to the normal Add-MailboxPermission command - in fact it should accept all the same parameters and pass them through without modification. Hope you find it useful!
The full script is below, along with the file to download underneath:

Download AddMailboxPermissionNoAutoMap.zip