Need Clarification

Hi @dugganab @SatheeskannaK @akshaaga 
we need a conformation that is there any way that we can pass a value in the email template, and it will be a personalized attribute, sent via email body That should not be visible to end users and we have to get it tracked in the AJO out-off the Box schema. 
How we can read Back it back in AEP ?