Distinguish Emailer leads from google PPC campaign

Distinguish Emailer leads from google PPC campaign

Clients from several sources visit our website (Google PPC campaing, Emails from Mail Chimp & Zoho campaings and Normal Website Traffic)...

I have a zoho enquiry form at my website...
I need to know how many Visitors fill the enquiry form from my emailer campaign (Mail Chimp and Zoho)...
This is very important for me because it will tell me effectiveness of the campaign and let me decide to go for paid version of Zoho and Mail Chimp Email Marketing...


Please Reply me ASAP...