How can I sync my Outlook calendar across all devices?

[AC Question]

I use a POP3 email account and Outlook 2016. I can sync email across devices just fine. How do I sync my Outlook Calendar across all devices? I can't seem to sync the outlook calendar with POP3 settings unless connecting to an exchange server and in this case it works find but otherwise I am not able to sync the outlook calendar to the Samsung Note 4. Any ideas?