This filter hook can override the admin notification email that is sent when a new user registers.  The default address that is used by the plugin is the address that is set in the WordPress General Settings (admin menu Settings > General).  This filter can set some other address and can also be used to send to multiple addresses.


add_filter( 'wpmem_notify_addr', 'my_admin_email' );

function my_admin_email( $email )
	/* The default email can be pulled into the filter with
	   the parameter $email.  This could be ignored, 
	   appended to, or changed altogether, as long as you
	   return a valid email.
	// single email example
	$email = '';
	// multiple emails example
	// $email = ',';
	// take the default and append a second address to it example:
	// $email = $email . ',';
	// return the result
	return $email;
See a list of all filter and action hooks