hide email address on user list

I would like to hide/suppress email addresses for all users (except admins) on the user list at /wp-admin/users.php.

I don’t see a way to do this — or perhaps I have something set up incorrectly.

Any thoughts?

While I’m at it, what’s considered a good email client I can use in wordpress that will allow me to throttle sending rates so as not to exceed my ISP’s limit?

Thanks!