Mailing from outlook (via ZOHO customer email hyperlink) and getting the correspondence to post to the emails in customer's account

Mailing from outlook (via ZOHO customer email hyperlink) and getting the correspondence to post to the emails in customer's account

How do I save my outlook emails directly to the customer's account, or potentials, etc.  We have the outlook plug in, but nowhere can we find how to do this.  Please advise.