Integrating Zoho Mail in to Zoho CRM

I am trying to figure out how to see my emails sent/received from Zoho Mail in the Zoho CRM with leads/contacts/accounts. I understand it is not possible to link contacts, but I should be able to see emails sent and received.

I have seen past questions about this and they almost always reference an add-on but I am not finding one. Can you please provide the steps. Thanks!!