Source Reference:

• Component: BuddyPress:: bp-core

  File: /bp-core/bp-core-filters.php :: Trac Source Line: 214

  	$subject         = '[' . $from_name . '] ' . sprintf(__( 'Activate %s', 'buddypress' ), esc_url( 'http://' . $domain . $path ) );
  
  	// Send the message
  	$to              = apply_filters( 'bp_core_activation_signup_blog_notification_to',   $user_email, $domain, $path, $title, $user, $user_email, $key, $meta );
  	$subject         = apply_filters( 'bp_core_activation_signup_blog_notification_subject', $subject, $domain, $path, $title, $user, $user_email, $key, $meta );
  	$message         = apply_filters( 'bp_core_activation_signup_blog_notification_message', $message, $domain, $path, $title, $user, $user_email, $key, $meta );
  
  	wp_mail( $to, $subject, $message, $message_headers );
  
  	do_action( 'bp_core_sent_blog_signup_email', $admin_email, $subject, $message, $domain, $path, $title, $user, $user_email, $key, $meta );
  
  	// Return false to stop the original WPMU function from continuing
  	return false;
  }
  if ( !is_admin() )
  	add_filter( 'wpmu_signup_blog_notification', 'bp_core_activation_signup_blog_notification', 1, 7 );
  
  function bp_core_activation_signup_user_notification( $user, $user_email, $key, $meta ) {
  
  	$activate_url = bp_get_activation_page() . "?key=$key";