email notification for several authors, one blog

I installed WordPress 2.7 yesterday, because my web host offers it. I’ve searched around, but I haven’t found my question addressed.

I’ve installed the blog in a password-protected directory. I want to make it available to a committee, so members can post draft documents as entries, and comment on each other’s posts. The email scheme I want:

1) all members get an email when any of them posts a new entry.
2) the author of a post gets an email when anyone comments on their entry.
3) the author of a comment gets an email when anyone comments on their comment.

I’m admin. I set it up so each user is an author, and joined with two other email accounts to see what happened when I posted and commented.

I get admin posts announcing a new user, and I got one about a comment awaiting moderation, but I didn’t get a notice when my user #1 posted an entry, or when my user #2 commented on it.

I’ve searched under “email notification” and similar terms. The discussions I’ve found were about admins not getting notified, in a situation where the admin was also the blog’s sole author. Is there a way to set it up the way I want for multiple authors, or is there another product I should try?