Question
Is it possible for an administrator to have some email addresses on their domain hosted by cPanel, and some hosted by Exchange or Outlook365?
Answer
By default, Exim(as configured by cPanel) does not provide for splitting delivery of a domain between 2 different locations. That said, it is possible. However, it does require advanced configuration and additional steps to do so. Many users have reported success using the method discussed in these forum posts:
https://forums.cpanel.net/threads/using-cpanel-and-office-365-in-a-hybrid-scenario.593683/