Microsoft Exchange Server 2010 : Indexing Exchange Public Folders

One of the major strengths of SharePoint is its ability to index (or crawl) a variety of content sources. This index can then be searched using keywords, enabling users to find the information they seek wherever it lives.

When it comes to search, the capabilities will vary depending on whether you are running Windows SharePoint Services or Microsoft Office SharePoint Server. With Windows SharePoint Services, only content stored within SharePoint (for example, lists and libraries) can be searched. With Microsoft Office SharePoint Server, searched content can include additional content sources such as file shares, regular websites, and Exchange Public Folders, which is the area of focus for this section. This section assumes you are using Microsoft Office SharePoint Server 2007.

Using Microsoft Search Server 2008 Search Server 2008 integrates with SharePoint, and it supports the ability to search Exchange Public Folders. One advantage is that you can enhance the Windows SharePoint Services search engine without having to upgrade to Microsoft Office SharePoint Server. There is also an Express edition of Search Server 2008 that supports this at no additional licensing cost.

Configuring search in Microsoft Office SharePoint Server is done through a designated Shared Services Provider (SSP). To access your SSP, click on the SSP name in the left-hand navigation menu in Central Administration. Inside the SSP, click the Search Settings link, which you'll find in the Search category.

It is important to note that crawling public folders from SharePoint is not supported in a native Exchange 2010 environment due to the lack of WebDAV support. Organizations wishing to use this feature must keep an Exchange 2003 or 2007 server in their environment that houses the public folder store. If you use Exchange 2007, at least Service Pack 1 (SP1) must be applied. Also, you must ensure that you have applied at least SP1 for your SharePoint farm.

1. Defining a Content Source

The first step in indexing Exchange Public folders is to create a content source. Each content source defines a certain type of content, such as Exchange Public Folders, SharePoint Sites, and so forth. You can have multiple content sources of the same type. To create a content source, click the Content Sources And Crawl Schedules link on the Configure Search Settings screen.

On this screen, the current content sources will be listed. Click the New Content Source button to create a new one. On the Add Content Source screen, choose Exchange Public Folders. SharePoint crawls public folders via their web address using the http://<exchangeserver>/public/<folderpath> syntax. Enter one or more addresses that you want to include in this content source. You'll notice that you can specify whether you want to recursively crawl this folder and all subfolders or just the folder itself.

You can also specify a full and incremental crawl schedule. As you would guess, a full crawl must be completed before incremental crawls can run. The crawl schedule is configured a little differently than other scheduling systems you may have worked with. Figure 1 shows what the schedule interface looks like.

The Repeat Within The Day setting at the bottom allows you to repeat the schedule throughout the day. When setting this option, you'll need to do a little math to calculate the ending time. Based on the settings shown in Figure 1, the schedule will repeat every hour between 6:00 a.m. and 6:00 p.m. Due to the strain this places on both Exchange and SharePoint, carefully plan your crawl schedules.

Figure 1. Configuring a crawl schedule

Figure 2 gives the full settings for an Exchange Public Folder content source.

Each content source can only have one set of crawl settings and schedules. Thus, if you need different settings based on different sections of your public folders, you should create additional Exchange Public Folder content sources.

For SharePoint to properly crawl your public folders, the crawler account must be granted Reviewer permissions to the folders it will crawl. By default, SharePoint uses a single account called the Default Content Access account when crawling all content sources. You can view and change this account by clicking the Default Content Access Account link on the Configure Search Settings screen.

Even though SharePoint has read access to all Exchange public folders, it doesn't mean that all users will. SharePoint's search engine is security trimmed, which means that it only shows results that the user has at least Reviewer permissions on. SharePoint is able to do this by also reading the folder's permissions and storing them within its index.

If you expect SharePoint to index non-Microsoft file formats, you may need to install an appropriate IFilter on your SharePoint index servers. This will apply to files found in any content source, including public folders. For PDF files, which is the most common need, you can install Adobe's free PDF IFilter (http://adobe.com/support/downloads/detail.jsp?ftpID=2611) or a third-party one from FoxIt (www.foxitsoftware.com/pdf/ifilter). If you'll be indexing a heavy amount of files, consider FoxIt as it performs much better.

Creating a SharePoint Scope To help users narrow the breadth of a search, SharePoint supports the use of scopes. A scope is a set of rules that allows you to set logical boundaries around indexed content. These rules can be based on a content source, a file type (such as Excel documents), and even metadata on the content (such as Author). Without scopes, users would search everything in the index—which can result in far too many hits to be useful. One idea is to create a scope that allows users to search only Exchange public folders.

Figure 2. Configuring an Exchange Public Folder content source