From any screen in the Google Apps Vault interface, click the word Vault in the upper left to display Retention, Matters, and Reports in the left pane. These are the items that appear when you first sign in to Vault.

After you create a matter, you can search your domain's Gmail data for information related to the matter.

To search for data within a matter:

1. Click a matter name.
2. Click Search in the left pane. You'll see the fields you can search:
   
   
3. Choose a Source:
   • All data: Search all data in your organization's Google Apps account.
   • Held data: Search all data on litigation hold for the matter.
   • Unprocessed data: Search the metadata of attachments that were not indexed.
4. Choose a Search method:
   • Accounts: Search for data in specific accounts, or across the entire domain.
     In the Accounts field, specify up to 500 user accounts, or leave it blank to search the entire domain.
   • Organization: Search within a specific organizational unit (OU).
     From the Organization list, choose the OU you want to search.
5. Optionally specify a Sent date range.
6. Optionally, in Terms, specify one or more search terms. Use search operators for complex searches.
   
   Note: Vault can only process date range and/or term searches for 110,000 accounts. If you have more than 110,000 accounts in your domain, limit the number of accounts to be searched by using the Accounts field.
    
7. Click Search.