Moderate Signup / Restrict Registration (WPMU & BP)

WPMU 2.9.2
BuddyPress 1.2.4

I need admins to activate newly registered users, not the users themselves. I haven’t been able to come up with a working plugin – probably because I’ve got MU and BuddyPress both running on my “members only” site.

I’ve modified the bp-core-signup.php file to send an e-mail to the user without the activation link and added an e-mail to the admin e-mail with the activation url. However, the user still ends up with the only e-mail, and it contains the activation url. Furthermore, the e-mail comes from noreplay@ which means that WP thinks I don’t have an admin e-mail set, which is not the case (I have one set).

bp-core-signup.php (originally)

function bp_core_signup_send_validation_email( $user_id, $user_email, $key ) {
	$activate_url = bp_get_activation_page() ."?key=$key";
	$activate_url = clean_url( $activate_url );
	$admin_email = get_site_option( "admin_email" );

	if ( empty( $admin_email ) )
		$admin_email = 'noreply@' . $_SERVER['SERVER_NAME'];

	$from_name = ( '' == get_option( 'blogname' ) ) ? 'BuddyPress' : wp_specialchars( get_option( 'blogname' ) );
	$message_headers = "MIME-Version: 1.0\n" . "From: \"{$from_name}\" <{$admin_email}>\n" . "Content-Type: text/plain; charset=\"" . get_option( 'blog_charset' ) . "\"\n";
	$message = sprintf( __( "Thanks for registering! To complete the activation of your account please click the following link:\n\n%s\n\n", 'buddypress' ), $activate_url );
	$subject = '[' . $from_name . '] ' . __( 'Activate Your Account', 'buddypress' );

	/* Send the message */
	$to = apply_filters( 'bp_core_activation_signup_user_notification_to', $user_email );
	$subject = apply_filters( 'bp_core_activation_signup_user_notification_subject', $subject );
	$message = apply_filters( 'bp_core_activation_signup_user_notification_message', $message );

	wp_mail( $to, $subject, $message, $message_headers );
}

bp-core-signup.php (my modification, not working)

function bp_core_signup_send_validation_email( $user_id, $user_email, $key ) {
	$activate_url = bp_get_activation_page() ."?key=$key";
	$activate_url = clean_url( $activate_url );
	$admin_email = get_site_option( "admin_email" );

	if ( empty( $admin_email ) )
		$admin_email = 'noreply@' . $_SERVER['SERVER_NAME'];

/* START MOD */
	$from_name = ( '' == get_option( 'blogname' ) ) ? 'BuddyPress' : wp_specialchars( get_option( 'blogname' ) );
	$message_headers = "MIME-Version: 1.0\n" . "From: \"{$from_name}\" <{$admin_email}>\n" . "Content-Type: text/plain; charset=\"" . get_option( 'blog_charset' ) . "\"\n";
	$message = sprintf( __( "Thanks for registering! And admin will confirm your membership.\n\nYou will receive a separate e-mail after this confirmation.", 'buddypress' ), $activate_url );
	$subject = '[' . $from_name . '] ' . __( 'Activate Your Account', 'buddypress' );

	/* Send the message */
	$to = apply_filters( 'bp_core_activation_signup_user_notification_to', $user_email );
	$subject = apply_filters( 'bp_core_activation_signup_user_notification_subject', $subject );
	$message = apply_filters( 'bp_core_activation_signup_user_notification_message', $message );

	wp_mail( $to, $subject, $message, $message_headers );
/* END MOD */

/* START ADD */
	$from_name = ( '' == get_option( 'blogname' ) ) ? 'BuddyPress' : wp_specialchars( get_option( 'blogname' ) );
	$message_headers = "MIME-Version: 1.0\n" . "From: \"{$from_name}\" <{$admin_email}>\n" . "Content-Type: text/plain; charset=\"" . get_option( 'blog_charset' ) . "\"\n";
	$message = sprintf( __( "New registration request from\n\nUsername: %s\n\nE-mail: %s\n\nPlease confirm by clicking the link below:\n\n%s\n\n", 'buddypress' ), $user_id, $user_email, $activate_url );
	$subject = '[' . $from_name . '] ' . __( 'Activate Your Account', 'buddypress' );

	/* Send the message */
	$to = apply_filters( 'bp_core_activation_signup_user_notification_to', $admin_email );
	$subject = apply_filters( 'bp_core_activation_signup_user_notification_subject', $subject );
	$message = apply_filters( 'bp_core_activation_signup_user_notification_message', $message );

	wp_mail( $to, $subject, $message, $message_headers );
/* END ADD */
}

So, after I submit a test registration, I get an with the information below:

from Members Only <[email protected]>
to [email protected]
date Thu, Jun 3, 2010 at 3:42 AM
subject [Members Only] Activate Your Account

hide details 3:42 AM (3 minutes ago)

Thanks for registering! To complete the activation of your account please click the following link:

https://members.domain.net/activate?key=xxxxxxxxxxxxxxxx

Could someone help me by directing me to a plugin or some way to change my code so that I’m able to restrict registration to admin approval?