Search has become a feature that most Microsoft Outlook users rely on daily. Searching in shared mailboxes within Outlook can yield different results depending on how the Outlook profile is configured. Therefore, it is vital to understand how different configurations affect the Outlook search feature.
First, it is important to know that the Instant Search feature is only available when Outlook is in Cached Exchange Mode. Additionally, the Instant Search feature is dependent on the Windows Desktop Search (WDS) feature of the operating system. The WDS Indexer indexes the mailbox data that has been synchronized to the locally stored Offline Outlook Data (.ost) file. Secondly, if Outlook is in Online Mode, the search feature passes the query to the Microsoft Exchange server, utilizing the index available on the server. Outlook has different ‘search scopes’ that help direct the query against a specific dataset to narrow the results. In some configurations, you are limited to using the Current Folder search scope when searching in a shared mailbox.
If the shared mailbox is added via the Exchange email account’s Advanced tab (using the Open these additional mailboxes option) or via Auto-Mapping, you should be aware of the following limitation when the Outlook Search option is set to the All folders setting (you can view your Search options by clicking on the File tab, clicking Options, and then Search): all search queries are executed against all folders of the primary mailbox. This occurs because the global setting was changed to ‘All folders’. However, searching across multiple mailboxes using the ‘All folders’ scope is not supported. In this scenario, after typing the search criteria to get instant results in Cached Exchange Mode (or pressing Enter in Online Mode), the search scope displayed in the upper left corner of Outlook shows All Mail Items or All Outlook Items selected. This is true even if you initiated the search in a folder of the shared mailbox. The end result is that no items from the shared mailbox are returned. To include the shared mailbox in the scope, you need to manually reselect Current Folder.
Based on your need, the profile may need to be reconfigured using one of several methods. These are detailed below.
Shared mailbox configuration
Allowed Search Scopes
Added via Advanced tab with DownloadShared Folders turned on
Added via Advanced tab with DownloadShared Folders turned off
Current Folder; All Subfolders
AutoMapped with Download SharedFolders turned on
AutoMapped with Download SharedFolders turned off
Current Folder; All Subfolders;
Second Exchange account in cached mode
Current Folder; All Subfolders;All Mail Items; All Outlook Items
Second Exchange account in online mode
Current folder; All Subfolders;All Mail Items; All Outlook Items
In Outlook 2010, the Search options include the following scopes:
Choosing All folders instead of the default of Current folder results in all queries being processed against the primary mailbox, even when you initiate the search from a folder within a shared mailbox. As detailed in the matrix above, the only way to use the All folders scope (All Mail Items or All Outlook Items) for a shared mailbox is to configure that mailbox as a second Exchange account in the Outlook profile.
Current Folder; Subfolders;Current Mailbox
Current Folder; Subfolders;All Outlook Items; Current Mailbox;All Mailboxes
Current folder; Subfolders;All Outlook Items; Current Mailbox;All Mailboxes
In Outlook 2013, the Search options include the following scopes:
If the Search options are set to anything other than Current folder, you may need to manually select the Current Folder scope in the Search tab when searching in a shared mailbox. This can be done either before or after you execute the search. If you do not click Current Folder, the search results will be limited to the primary or secondary Exchange accounts in the Outlook profile. No items will be included from shared or AutoMapped mailboxes, or those added by using the Open these additional mailboxes option.
Exchange administrators may be interested in the following Microsoft TechNet article, which explains how to disable Auto Mapping:
Disable Outlook Auto-Mapping with Full Access Mailboxes
How does the addition of the "All mailboxes" option affect this? When I've tested this with an additional mailbox (added via the "Open these additional mailboxes" method) it seem the All mailboxes option still doesn't search additional mailboxes, only
those which are setup explicitly in the accounts list. That's backed up by going into Search Tools, Locations to Search, in which I see each of my Exchange/POP3/PST attached mailboxes, but the additional one doesn't show up.