Link emails with Contacts already in the crm

Hello, we are running Version 7.6.3
Sugar Version 6.5.23 (Build 1061)

We have been using a deskop version of Maximixer CRM but need to move to an online CRM.
The problem we have is that any Incoming email in SuiteCRM is not automatically associated with a Customer (Contact) record (as shown in the uploaded pdf when using Maximizer CRM).
Therefore, how do we know if the email received is already associated with a Contact in SuiteCRM?
How do we add this extra field that show the Contact name on all emails?
Please see our attached pdf.