What is the best method to sync office365 email into CRM?

What is the best method to sync office365 email into CRM?

Hi, I hope you can help me pick out the best method to sync Office 365 email into CRM. I am currently using POP3 to sync email into CRM. It works fine in CRM but in our window Outlook, all new emails auto change status to "read" and make all users confuse. Please share your method if you can, thanks.