Registration Form: Users emails from specific domain

[rjawali]

Is there any way that I can customize the registration form so that users with email addresses from particulars domain only can register into the forum?
For Instance: Users can register if and only if they have "yahoo.com" email.

[Kindred]

by default, you can BAN users form a certain domain, but there is no restriction capability to stop people unless they use a specific domain.

There MIGHT be a mod to do so...  but I don't recall specifically.