Windows Desktop Search 4 lagging Outlook

When utilising Microsoft Outlook in Cached Exchange Mode, Windows Desktop Search 4 is used to index the content in the Outlook OST to allow users to perform fast searches for emails and content within Outlook.  When Windows Deaktop Search 4 goes to first index email within a users inbox, this creates large amounts of local disk activity on the users workstation which causes performance issues especially if the user does not have a Solid State Disk (SSD).

This can be resolved by throttling the amount of items Windows Desktop Search 4 can index per minute.  Use group policy to implement Windows Desktop Search throttling by modifying the following group policy setting:

Computer Configuration\Administative Templates\Windows Components\Search\Enable throttling for online mail indexing

Here we have it limited to only index 60 mail items per minute.  This resolved Windows Desktop Search performance issues at my clients site.