simple-wordpress-cronjob-test-plugin.php

<?php
/*
Plugin Name: WordPress Simple Cronjob test
Plugin URI:
Description: This is a Simple WordPress Cronjob testplugin
Version: 1.1
Author: Rene Reimann
Author URI: http://www.rene-reimann.de
*/

add_filter( 'cron_schedules', 'wsct_add_schudle' );

function wsct_add_schudle( $schedules ) {

	// Adds once weekly to the existing schedules.
	$schedules[ 'wsct_30_seconds' ] = array(
		'interval' => 30,
		'display'  => __( 'WSCT 30 seconds' )
	);

	return $schedules;

}

if ( ! wp_next_scheduled( 'wsct_task_hook' ) ) {
  wp_schedule_event( time(), 'wsct_30_seconds', 'wsct_task_hook' );
}

add_action( 'wsct_task_hook', 'wsct_task_function' );


function wsct_task_function() {

	$adress = 'YOUR@MAILADRESSE.TDL';
	$subject = 'WordPress Simple Cronjob test Automatic email';
	$content = "Automatic scheduled email from WordPress.\nSend From " . $_SERVER['SERVER_NAME'];

	wp_mail( $adress, $subject, $content );

}

register_deactivation_hook( __FILE__, 'wsct_deactivate' );

function wsct_deactivate() {
	wp_clear_scheduled_hook( 'wsct_task_hook' );
}