User Registration doesn’t send out password

When a new user registers onto the blog, they are never emailed their password. When they click on Forgot password and fill out/submit the form the page says:

“The e-mail could not be sent.
Possible reason: your host may have disabled the mail() function…”

Here’s the registration page https://www.stuffwelike.com/stuffwelike/wp-login.php?action=register

I’m using v2.3. Also my host is BlueHost.com.
Any solutions?