Re: Exclude E-Mail-Hoster from Registration
If you are using WP MU (multisite…or whatever you like to call it), then you can do this easily at: http://yourdomain.com/wp-admin/ms-options.php Things like this is why I’ve installed my BP on WPMU even though I don’t use more than one blog. The good thing is that since WP 3.0 you can switch to MU easily. Just be sure to test it first and do a good backup.
I want to say there was some way to hack WP single install, but I can’t remember.