[xwiki-users] How does WatchListRss identify the user to deliver the feed specific to a given user

Hi. I am trying to understand and use RSS feed to watch the Main space and few specific pages in another space on our XWiki installation (version 2.1). I am using Thunderbird as my RSS reader since I already use it for reading a bunch of other RSS feeds. I am unable to get any meaningful feed when I enter the URL provided in the WatchListManager page (which is something like <hostname>/xwiki/bin/view/XWiki/WatchListRss?xpage=plain&outputSyntax=plain into Thunderbird. To investigate the feed returned by the above URL, when I viewed the URL in Firefox (and I have authenticated with the XWiki in another tab), I see the correct list of feed items, but when I view the URL in Firefox as an unauthenticated user, the feed list is empty. So obviously user information is being passed to WatchListRss somehow. The question is how do I authenticate as a specific user when using standalone or feed readers such as Thunderbird or Outlook-2007? Does the feed URL have to be modified in any way? Thanks, Milind