Go to cpanel > cron jobs > standard.
At the top is an email field
Change to an alternate email
Or
FThe way to change the email account WHMCS sends the daily cron reports to…
1. Log in to WHMCS.
2. Click on Configuration -> Administrators.
3. Click on the little edit-button for the full administrator.
4. Change the email address.
Alternatively, if you want to prevent these emails being sent out altogether, go to ..
1. Configuration -> Administrator Roles -> Full Administrator.
2. Uncheck the box right at the bottom that says ‘System Emails’.