Integration Mail, CRM, Campaign

Hi, I joined Zoho just one day ago. I can not find out how Campaigns, Mail and CRM are integrated?

For instance, I would like to be able to see all the communications with my leads and clients (through ZOHO mail, CRM, Campaigns).

For instance, I plan sending the Christmas greetings both to my clients and leads. Zoho Campaigns is a great tool to keep truck on customer behaviour. Is it possible to share such information in CRM interface?

Thanks, Anastasia