How to stop emails do NOT sync to the CRM

Hello All CRM Expert,

How to stop emails do NOT sync to the CRM.

I tried to mailbox property set None option Incoming,Outgoing,(Appointment,Task,Contact)

Setting --> System Setting --> Email --> Configure default synchronization method -->set None option Incoming,Outgoing,(Appointment,Task,Contact)

Please help me if any have good solution for this issue.

Thanks