Gday Everyone,
I have refcently needed to add the ability of allowing or rejecting registrations by the email domain suffix.
"limited domains" provided a explicit match and could not cope with complicated (multiple email servers across many sub-domains).
Anyway I am not sure how to go about submitting code so I will just mention it here and hope that someone can make use of it.
http://innovation.cfl.mq.edu.au/rgmu/wpmu-1.2.3-emaildomain.patch
Russ