Show the mailinglist subscription form to subscribe to a certain mailinglist id.
- Required; the id of the mailinglist resource that is being subscribed to.
- Which form template to render. Defaults to the template
All other parameters are passed in to the template which is being rendered.
The form is at least supposed to have an email input field. Besides email, it can have name_first, name_surname_prefix and name_surname fields, which will be stored in the recipient table.