Include a summery of a password-protected post on the feed

Hi,
I was wondering how you could publish only the summery of password-protected posts into a un-password-protected feed.

I want to do this because I want to let my (paid) subscribers know that I posted something new, and let them see it. Then I use feedburner to send out an e-mail to my subscribers about the new post, and then they click on the link in the e-mail, which directs them to my blog. Then they would have to type in the password to see the entire post