Email in ZOHO CRM

Email in ZOHO CRM

I have several questions. 

1. what "Email Insights & Analytics " you mean? I did not see this in ZOHO CRM. 
2.  If we send email in Gmail, will ZOHO CRM display email status? (Open, read, unread, etc).
3. we have two office in two different location and even using two different domains. can these two email domains to be integrated in one ZOHO CRM?