How can single form send two emails using different titles and bodies

@SjoerdSmeets With some help of the Form docs, albeit a bit hidden I have to admit... The following seems to be doing what you are looking for.

Note: I used a fresh install of Grav 1.6.0-beta.6 with Quark and an inherited theme.

• Create a new page with a contact form:
  TXTCopy

  user/pages/03.contact/
    form.md
  

• Add the following frontmatter with two separate email actions:

  YAMLCopy

  ---
  title: Contact Form
  
  form:
    name: contact
  
    fields:
        - name: name
          label: Name
          placeholder: Enter your name
          autocomplete: on
          type: text
          validate:
            required: true
  
        - name: email
          label: Email
          placeholder: Enter your email address
          type: email
          validate:
            required: true
  
        - name: message
          label: Message
          placeholder: Enter your message
          type: textarea
          validate:
            required: true
  
    buttons:
        - type: submit
          value: Submit
        - type: reset
          value: Reset
  
    process:
        - email:
            # To myself
            to: "{{ config.plugins.email.to }}"
            subject: "Email to myself"
        - email:
            # To visitor
            # Using defaults for 'to' and 'from'
            subject: "Email to visitor"
            body: "{% include 'forms/visitor.html.twig' %}"  <-- a custom template
  ---
  
  # Contact form
  
  Some sample page content
  

• In your inherited theme create a new Twig template 'users/themes/mytheme/templates/forms/visitor.html.twig'. Add the following content:

  TWIGCopy

  <p>This is the body for the visitor's email based on template "forms/data.html.twig"
  which can be found in folder "/user/plugins/form/templates/forms/".</p>;
  
  {% include "forms/data.html.twig" %} 
  

Hope this helps...