Default Filters for Exchange Search

In Microsoft Exchange Server 2010, Exchange Search includes a number of default filters to index different types of message attachments. You can also install filters to index additional file types.

When managing or using Exchange Search and the features that depend on it (such as Multi-Mailbox Search), consider the following factors:

• Unsearchable items   When Exchange Search can't index a particular file type for any reason (for example, if a filter isn't installed), the search for the file type fails.
• Safe lists   Certain file types don't contain any indexable data and therefore aren't indexed. These file types are indicated by a null filter entry in the registry. Items with an attachment type for which a null filter exists aren't searched and aren't returned as unsearchable items.

This topic includes the default filters and safe list filters that are installed on an Exchange 2010 Mailbox server. It also shows you how to use the Shell to retrieve

Looking for other management tasks related to Exchange Search? Check out Managing Exchange Search.

Default Filters

The following table lists the default search filters installed on an Exchange 2010 Mailbox server. You can retrieve the list of default filters on a Mailbox server from the following registry location:

HKLM\SOFTWARE\Microsoft\ExchangeServer\v14\MSSearch\Filters

Default Safe List Filters

The following table lists the default safe list filters that are installed on an Exchange 2010 Mailbox server. Exchange Search doesn't index file types for which a safe list filter exists. You can retrieve the safe list filters from the following registry location:

HKLM\SOFTWARE\Microsoft\ExchangeServer\v14\MSSearch\NullFilters

Use the Shell to retrieve default and safe list filters

You can use the Get-ChildItem cmdlet to retrieve registry keys. This is particularly useful when you need to retrieve a large number of registry keys, such as the list of default and safe list search filters.

This example retrieves the list of default search filters used by Exchange Search on an Exchange 2010 Mailbox server.

Get-ChildItem HKLM:SOFTWARE\Microsoft\ExchangeServer\v14\MSSearch\Filters | Format-Table PSChildName

This example retrieves the list of safe list filters for file types that aren't indexed by Exchange Search on an Exchange 2010 Mailbox server.

Get-ChildItem HKLM:SOFTWARE\Microsoft\ExchangeServer\v14\MSSearch\NullFilters | Format-Table PSChildName

For detailed syntax and parameter information, see Get-ChildItem.