Q: How does Outlook support RSS feeds?

A: The evolution of RSS has been tumultuous, resulting in various versions with different acronym definitions, depending on the influencing party—for example, RDF Site Summary (RSS 0.90/1.0), Rich Site Summary (RSS 0.91), and Really Simple Syndication (RSS 2.0). In addition, a new syndication specification named Atom was developed to consolidate and advance RSS. Atom makes RSS easier to visualize for users, consolidates versioning, and uses Internet Engineering Task Force (IETF) standards. Atom was implemented through the IETF proposal process as Request for Comments (RFC) 4287.

Now that RSS has gone mainstream, having RSS functionality in a personal information manager (PIM) is important. Microsoft Office Outlook 2003 does not provide native RSS feed functionality, although a few third-party options are available for incorporating RSS. NewsGator and intraVnews both integrate well with Outlook 2003.

Microsoft Office Outlook 2007 provides the ability to consume RSS feeds natively. Office 2007’s built-in RSS feed reader, or aggregator, supports RSS 2.0, RSS 1.0, RSS 0.9x, Atom 1.0, and Atom 0.3.

Several methods let you add new RSS feeds to Outlook 2007’s aggregator. If the computer running Outlook 2007 also has Internet Explorer (IE) 7.0 installed, then IE 7.0’s Common Feed List feature makes RSS feeds added through IE 7.0 also available to Outlook 2007. The Common Feed List is a local XML cache of the subscribed feeds held in individual files. In Windows Vista, feeds are stored in C: \Users\username\AppData\Local\Microsoft\Feeds. This cache is accessible to other applications that run under the same user account, including Outlook 2007.

You can also add RSS feeds to Outlook by applying the specific URL for the XML file in one of the RSS or Atom formats. The Account Settings optionis used for feed administration. To add a new RSS feed, select Tools, Account Settings, RSS Feeds, New. Enter or copy and paste the feed URL, as Figure 1 shows, and click Add.

Outline Processor Markup Language (OPML) files also let you import and export RSS feeds. An OPML file is an XML file that’s suitable for describing lists. OPML files are probably most noted for their ability to share lists of RSS feeds. Outlook 2007 can import from and export to a properly formatted OPML file. The import process lets the user select individual feeds within an OPML file while importing, as Figure 2 shows.

RSS feed content retrieval is initiated by the client application. Outlook polls a syndication source for new items at regular intervals, with the default interval set as once per day. If the default storage location for Outlook is configured to be a Microsoft Exchange Server mailbox, then Outlook can store RSS feed content in the user’s mailbox on the Exchange server. If Exchange is not used, then Outlook downloads RSS content to a local .pst file. In either case, RSS feed content arrives in the default mailbox storage location through the Outlook client. This is important because RSS content bypasses real-time email server antivirus applications. If RSS content is stored in an Exchange mailbox, then using an Exchange-aware antivirus solution to scan the Message Store might be necessary.

Feed enclosures are file attachments that are made available through RSS feeds. Enclosures present security risks in the same way that email attachments do. Outlook 2007 disables the automatic download of feed enclosures by default. You can change this setting in the Feed Properties window. Of course, a current file-level antivirus defense is also recommended. Note that RSS feeds do not flow through any Exchange-based antivirus solution that you might deploy—they would be caught only through a Message Store scan.

As I already mentioned, the Account Settings option lets you administer RSS feeds in Outlook 2007. Figure 3 shows how to add, remove, or change feeds. Unfortunately, the Account Settings window is not expandable, and because of the nature of some of its configuration options, you must close the window before you can return to an Outlook folder. Thus, Account Settings is a poor choice for an RSS management interface. A better option would be a separate RSS subscriptions window, employed by a third-party aggregator that works with Outlook.

Individual feeds have some specific settings that you can use the Account Settings option to configure. In the Account Settings window, double-click a feed, or select a feed and click Change. In the properties page that opens (i.e., the RSS Feed Options window), set the feed’s delivery location, and specify whether to automatically download enclosures and whether to download the full HTML version. Figure 4 shows these options. You can also control a feed’s polling frequency.

Although Outlook 2007 offers native RSS feed functionality, it is not a very scalable solution and does not provide easy granular administration of feeds. If a user subscribes to more than a couple dozen feeds, then Outlook 2007 might not be the best tool for the job. Third-party solutions that integrate with Outlook 2007 and Outlook 2003 provide a more complete solution with easier administration than Outlook 2007’s RSS implementation. However, Outlook 2007 does provide an email-like interface for users to access several important RSS feeds.