You will want to make sure that your emails meet the following requirements so that your prospect's replies are tracked.
- Connection with your email server. You can set up with Gmail or Outlook.
- Subject Lines must match, any changes to the subject will prevent it from being picked up as a reply
- They have to reply from the email address you sent the email to, or from a permutation of their first/last name and domain.
Learn more about these requirements here.