Can I switch off my computer when the campaign is ongoing ? I afraid that when I off or disconnect my computer, the process will be abort. Can someone help me and explain how it works ? The ougoing mails are from my computer or not ?
the emails will send per cronjob. So if your wp-cron works correct you can switch off your computer. The cron will push when a user visit your site.
Comes an white page if you try to open http://www.yourdomain.com/wp-cron.php ? Thats fine.
Important: if you dont have any visitors there will be no automatic cron and no emails are send. In this case you must start your WordPress Cron via another cron service.