I need know about the ESP part in this ZOHO

The beauty of the CRM lies in its ability to provide a unified solution which is capable of providing a communication channel from within, without switching between the CRM and the e-Mail Application, independent of any such application outside it. The Zoho keeps a record of our email exchanges with a specific lead or interaction as well as related sales details which can be tracked in a single location in the CRM. One can go to the contact's detail page and then scroll down to the e-Mail related list. All the email conversations related to any particular customer or contact can be viewed here. One can also see the linked sales details in this place. This will help the salesperson having a more effective preparation about the case and can make the discussion very effective.