Access rules (email filters)

Some of us know about a few CMS's where the administrator can filter the incoming email registrations. For instance, you could register with your@institution.edu, but not with your@gmail.com or your@yahoo.com. Here's how you do it:

Add an ACCESS RULE by going to ADMINISTER -> ACCESS CONTROL-> ACCESS RULES [for Drupal 4.7.4].

Then add 2 email address rules:

Deny %@% (which should block everyone) and Allow %@allowed.com (which will allow people with anyone@allowed.com). That's pretty much all there is to it. Have fun with Drupal!