I will show you how to setup your SharePoint Search Server Express to search and retrieve your files located on a shared folder inside the network and behind the firewall.
So when we setup search in SharePoint we can use any shared folder as a content source. This work ok if you are inside the network but how to give the same functionality for users outside the company without storing all those files in SharePoint?
First we need to make the files available trough the same IIS web site that is available from outside. For this we create a new Virtual Directory under IIS that points to the shared folder that contains the files. Make sure that you don’t enable directory browsing and leave checked only the Read checkbox. Next on the same screen make sure that you click “Create” button under the Application settings to create a new application name to make this virtual directory accessible. There is no need to give any Execute Permissions as we don’t run anything from there. See screen shoot:
This settings will give us access to the files on the shared folder over the Internet but only if you know the exact name of the file.
Next step is to configure SharePoint. Under the search settings you should see “Server name mappings” (Search Server > Search Administration > Server name mappings). There is where we are going to tell SharePoint to replace the file://yourserver/share with the link to the Virtual Directory that we previously created in IIS. After adding the new mapping reset the crawl context and start a new full crawl for the content sources.
Note: Even if the “Server name mappings” link is under “Queries and Results” it seems that the replacement is done during the indexing process.