I Need Some Techie Help

I want you guys to be able to subscribe to new posts via email so I can keep you updated of new materials. But I want to do it in such a way that only a portion of the post will be delivered by mail, and the rest of the post will be available at this site. That way, you can continue to see other useful updates that I will be making here. I tried using Feedburner, but it seems that it delivers the entire post via email, and I don't know how to tweak it to make it work the way I want it. Hope you guys can help me with this little dilemma of mine, or maybe let me know of other similar tools that I can use.

Thanks a lot in advance! Happy Friday!