2 min read

Automapping Mailboxes in Exchange 2010 and Outlook

There is a nice new feature in Exchange 2010 with Outlook 2007/2010/2013, called automapping.  Autodiscover automatically maps all mailboxes in Outlook to which a user has Full Access Permission.  This can also cause issues.

There are a couple of scenarios when this will happen:

  • An administrator grants full access permissions for a user to access another user’s mailbox.
  • The user has full access permissions to a shared mailbox.

If the user has access to many mailboxes, this behavior may cause performance issues when Outlook starts. For example, in some organizations, administrators have full access to all users’ mailboxes in their organization. If this is the case, Outlook tries to open all mailboxes in the organization.  I thought I read somewhere that Outlook only attempts to open 10 mailboxes, but I can’t find the reference anymore.  In any case, can you imagine downloading email for 10 accounts to your Outlook Client?

In some ways this is a nice feature, because in the past you would need to manually add an additional mailbox in Outlook by going to Account Settings Outlook Profile More Settings Advanced and Open these additional mailboxes.


As you can see in my profile, I have no additional mailboxes added, yet when I open Outlook I see additional mailboxes.


If I right-click and try to close a mailbox I receive the following error message:

“This group of folders is associated with an e-mail account. To remove the account, click the File Tab, and on the Info tab, click Account Settings. Select the e-mail account, and then click Remove.”


As I mentioned, there are no email accounts associated.  Autodiscover automatically mapped the accounts to my Outlook profile.

How do you remove them?

Well logic would tell you that granting Full Access Permission allowed this to happen, so removing Full Access Permission from the mailbox would remove it.  That is NOT the case though.  After removing Full Access Permissions, closing, and reopening Outlook the mailboxes are still there.

There is actually a bug and removing this is quite tedious.  There are two ways in which I know how to fix this:


  1. Open ADSIEdit.msc
  2. Connect to the Default Naming Context.
  3. Locate the mailbox to which you had been granted Full Access Permissions
  4. Right-click on the object and view properties.
  5. Scroll down to MsExchDelegateListLinked attribute.
  6. Click Edit, select the User Object and click Remove.


Active Directory Users and Computers ( view Advanced Features)

  1. Open ADUC, View Advanced Options
  2. Locate the user account to which you had been granted Full Access Permissions
  3. Right-click on the object and view properties.
  4. On the Attribute Editor tab, find the MsExchDelegateListLinked attribute.image
  5. Click Edit, select the User Object and click Remove.image

If I close and reopen Outlook the mailboxes are no longer mapped.



How do prevent this in the first place?

There is also the ability to disable automapping when Full Access Permission is granted to a mailbox through PowerShell.  This is apparently new in Exchange 2010 SP2.

Add-MailboxPermission -Identity User@company.com -User admin@contoso.onmicrosoft.com -AccessRights FullAccess -AutoMapping:$false


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