One option you have for managing follow up is to add call back tasks to the email series. If you have an email series of [email 1], [email 2], [email 3], you can edit that series to add call back tasks to look like this [email 1], [task], [email 2], [task], [email 3]. Let me know if you need help with that. It is on the Edit page.
Here is video to explain editing emails so that they have call back reminders.
The other option is to schedule the follow up after each call you make and that is very easy to do on the Log an Interaction page.