There are two possible explanations for this behavior:
  1. The autoresponder is not enabled.
  2. A constituent registration information (CRI) question type to capture name, email address, and/or other standard constituent fields is not included. Without that question type, the system is not told how or where to match information submitted to a constituent record and because of that, the interaction is not connected to a constituent and no autoresponder can go out. If a survey does not contain a CRI question and a user isn't logged in when taking the survey, then it will be submitted anonymously.
Note: This must be a CRI question type and not just requesting the email address or other constituent information in additional questions.