Automatic welcome email issue


I’ve figured out how to create automatic emails…

Now I have another issue, I’ve created a “Referral campaign” which requires me to send an automatic thank you email to the “referee”.
I’ve set the “Primary record” as the “referral” and added a panel called “Referee details” which would take all the contact details of the referee. I just realised that the email will be sent to the “Primary record” instead of the “Referee”. Is there another way for me to select the “Referee” email instead of the referral?
There is another item on the dropdown list in Workflow > Actions > Email > To > Related Field although I’m not sure if that will help…

I hope this doesn’t sound confusing!

Please help if you know the answer. Thank you all in advance!