Cron for email notifications

Hi,

My users do not receive emails. All Easysocial alerts activated, all users accepted and published, settings alert polling interval 30 sec.

Have tried to set up a cron within my host. Here some questions as it does not work for the moment.

Attached is a picture of my host cpanel.

1) Script to be run from: choose between:
a) http://mywebsite.org/
b) http://www.mywebsite.org/
c) http://mywebsite.hostprovider.com/

my site runs at url : http://www.mywebsite.org (with redirection from mywebsite.org to http://www.mywebsite.org)

what to choose?

2) what to put after the /:
a) index.php?option=com_easysocial&cron=true"
b) components/com_easysocial/cronjob.php

i tried both and tried also to modify within the cronjob.php:
$host = 'mywebsite.org';

Help welcome

Thanks!

Raph