Notify user for new article

Hi all,

I just discovered wordpress, installed it and I must admit that I’ve been impressed by its easiness to use.
However, today I need a feature I did not find yet.
I would like to automatically notify my web site users when a new article is published. Of course, only users who subscribe/unsubscribe to this specific mailing list would receive such notification.

is their any plugin for wordpress that would do this task ?
Thans kin advance for your help
Eybus