Looking for RSVP application
I'd like to send out emails with an invitation to clients / contacts. These emails should include one or more buttons / links (e.g. to a form) where a user can answer if they will attend a meeting or not (or give an additional information).
Was testing some forms, but these solutions can't prepopulate fields, e.g. contact name, in a secure manner (e.g. jotforms always query string parameters, but that would make the form not very secure).
Did I miss this kind of feature?