let me start saying your plugin is fantastic, I really appreciate your work and I use it in all my client wp websites with the cron option to backup into an ftp.
now, I have an small request that I think would enhance the cron notifications feature:
in cloner.cron.php you have the following line of code:
$headers ="From: \"Cronlog XCloner\" <email@example.com>\n";
which confirms me that you're hardcoding the from header for the cron notification. that is causing some delivery issues with google for example.
would you please add a field in the backup configuration screen like you have it for the notification email to override this hardcoded value? or at least maybe use wp site email here instead of firstname.lastname@example.org? the first option is more flexible, though.