To transfer iCloud emails to Office 365, try using the 4n6 Email Backup App. The app is an easy-to-use software that lets you safely backup your iCloud emails and then export them to Office 365. Here's how you do it: just set up your iCloud account in the application, backup your emails, and then transfer them to your Office 365 account using the migration feature of the app. This software retains email metadata, is selective in migration, and facilitates a smooth transition from iCloud to Office 365.