Ninja Forms PHP

ninja_forms_email_filter.php

<?php
function my_cool_filter( $setting, $setting_name, $id ) {
	global $ninja_forms_processing;

	// Bail if we aren't filtering the to setting
	if ( 'to' != $setting_name )
		return $setting;

	// Bail if our notification's setting name isn't admin_email
	if ( 'admin_email' !=  Ninja_Forms()->notification( $id )->get_setting( 'name' ) )
		return $setting;

	// Get our submitted field value	
	$value = $ninja_forms_processing->get_field_value( 3 );

	// Bail if our value isn't set or is false
	if ( ! $value )
		return $setting;

	switch ( $value ) {
		case 'zach':
			$setting[] = '[email protected]';
			break;
		case 'kevin':
			$setting[] = '[email protected]';
			break;
		case 'james':
			$setting[] = '[email protected]';
			break;
	}

	return $setting;
}

add_filter( 'filter__email_message', 'my_cool_filter', 10, 3 );