How to send mail to salesteam in form triggered flow in SF Marketing Cloud Growth

Hi everyone, 

My company recently migrated from HubSpot to Salesforce Marketing Cloud Growth and I am trying to rebuild a simple contact form flow.

The goal is to create the following process:

When someone submits the contact form:

1. The Flow should first check whether the person already exists in our Salesforce database.

If the person does not exist:

• Create a new Lead record in Salesforce.
• Send a confirmation email to the person who submitted the form.
• Send an internal email notification to our sales team containing the lead information:
  • Name
  • Email address
  • Question/message submitted through the form

If the person already exists as a Lead or Contact:

• Do not create a duplicate record.
• Still send a confirmation email to the person who submitted the form.
• Send an internal notification to our sales team containing:
  • Name
  • Email address
  • Question/message submitted through the form

The main goal is to avoid duplicate records while ensuring both the customer and sales team receive the correct notifications for every form submission. 

I tried using the Send Email action directly in the Form-Triggered Flow, but I received this error:

I then tried creating a Subflow. However, the information from the form submission was not passed correctly to the Subflow. The Subflow either:

• Did not send an email at all, or
• Sent an email with incorrect Lead data, or
• Sent an email without any form information.

Any advice or examples of the correct Flow architecture would be greatly appreciated.

Thank you!