ZOHO Mail and CRM integration

ZOHO Mail and CRM integration

I upgraded to the professional ver. and added ZOHO mail add-on and Outlook add-on.  The mail program does not have my CRM contacts in it, why?  It seems like it does not communicate with CRM at all.  If it does not, I will not be keeping the ZOHO Mail add-on.  How do I fully integrate my ZOHO Mail with my ZOHO CRM?