This article discusses how to remove automapping for shared mailboxes in Microsoft Outlook for Microsoft Office 365.

In Microsoft Outlook 2010 and in Microsoft Office Outlook 2007, Autodiscover automatically maps to any mailbox for which a user has full access permissions. Autodiscover automatically loads all mailboxes for which the user has full access permissions in the following scenarios:

  • 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 many mailboxes to which he or she has full access, 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.