We are into recruitment business.
On the sales side, we have leads which are companies. We contact decision makers in these companies to and propose our recruitment services to them. We send these leads emails, we call them, we put notes against the leads in vTiger, we schedule meetings with them, we put reminders to call them every 3 months if they are currently not interested. This part is already working fine in our vTiger 6.3.
On the candidate side, this is what works for our industry:
Click on the link called "login to demo account". This is an open source project. We currently dont use it, but the functionality we need within vTiger is similar to what is shown in this project here.
Please see this video here for more clarity on this idea:
All the communication (email with multiple SMTP servers, inbound and outbound phone), needs to be saved for all candidates, leads...