Really Simple Syndication is a way to get news and other info sent to you automatically using some sort of a feed reader- They send the feed, you use software of some sort as your reader.
In MS Office Outlook 07 and some other email clients, you can get these feeds sent to your email account- they won't show up as a new email necessarily, you would be overwhelmed- but will instead be placed in with your folder groups as an RSS feed- Read more from a favorite of mine for many years now, The Crabby Lady from Microsoft Office... Unlike most MSoft things which I dislike tremendously, old Crabby is good and definitely to the point. She also makes me smile.
If you are wanting to continue learning about what all the Office suite can really do or if you get stuck, Crabby is the lady for you. Here is some info from her about RSS- but there is way, way more online. Crabby on RSS