Hi @CMiller9,
This is currently not possible in HubSpot, forms can only create contact records (which are the basis for email communication) from the “official” email field. There currently isn’t a native way to reference another property for email sending. There might be ways to accomplish this with integrations or custom code in Operations Hub Professional, but – as @DeliveryByJess explained – there is also a legal aspect to this.
The person submitting the form cannot express consent on behalf on someone else. There needs to be a legal basis for processing a contact’s data and a legal basis for sending marketing/sales communication to that contact – and it would be hard to argue that this legal basis is given for a referred contact. GDPR is pretty strict on this. The friend can’t be enrolled by action of someone else, they must themselves take action. While the requirement for the legal basis leaves some room for interpretation, the best option is to have them fill out a form including a consent and privacy notice.
If you want to find a solution here, you’d have to approach this from a different angle. The first person could share information with their friend instead of submitting their email address. After submitting the form, you could send them a confirmation email that includes instructions on how to share this with a friend. This can for example be achieved with a mail-to-link generator.
Hope this helps!