Email sync using Microsoft CRM for Outlook

Hello all,

My company uses the CRM 2015 Online. After installing the outlook plugin, I tried tried synchronizing using Server side synchronization. However it gave me a failure notice during testing. Later I tried synchronizing using the Exchange or "Microsoft CRM for Outlook" and while I was successful in synchronizing Records and Appointments, I'm still unable to sync the emails.

Thank you in advance for your suggestions.