In each of the emails sent from FieldNotes platform, you can track the email view by each of the recipients. You can see when it was viewed and how many times it was viewed.
Note that this is dependent on the email client and if the user has disabled auto-download of images or previews etc, the data might not get reported back. For all messages sent a tick mark indicates that it is read by the contact. Hovering over the tick mark provides details on how many times the email was viewed etc.
The conversation tab also provides a breakdown on how many SMS and Emails were sent and how many of these were replied to or viewed (in case of emails).