Moving your local data across these two clients can be a problem. This is all good and fine, except if you are switching over from Apple Mail to Office 365 in Windows Outlook. There are many packages that you can choose from depending on your needs.
You could choose monthly or yearly subscriptions and get to use these apps in multiple machines in both Mac and Windows. Office 365 is a set of products and subscriptions offered by Microsoft that includes Office apps like Word, Outlook, PowerPoint, and Excel.