Automatic
replies.

1. Write the reply

1. Verify an address under Recipients. This is where replies to your confirmation will go.
2. Open your form and choose Set up visitor replies.
3. Write a subject and a short message. Be realistic about when someone will respond.
4. Choose the verified reply address and select Preview visitor reply. Preview uses unsaved settings and does not send email.
5. Connect and enable Turnstile in the form’s settings, install your widget and consent checkbox, then turn on visitor replies and save.

Email is sent from Form Koi’s sending address with your selected address as Reply-To. Subjects can contain up to 150 characters; the plain-text message can contain up to 3,000. Visitor names, submitted text, files and template variables are not inserted. The opt-out footer is always included.

You can save a paused draft before connecting Turnstile. Updates take effect only after saving. A conflicting edit in another window asks you to reload instead of overwriting it.

2. Add the consent checkbox

Add a single email field and this optional checkbox to your existing form. Leave it unchecked. Keep your existing Form Koi action or JavaScript submission handler and your Turnstile widget.

<label for="email">Your email</label>
<input type="email" id="email" name="email" required>

<label>
  <input type="checkbox" name="_formkoi_autoreply" value="true">
  Email me a confirmation that my message was received.
</label>

With JSON, send _formkoi_autoreply: true only when the visitor chooses it. The HTML string "true" is also accepted. Missing, false or repeated consent values do not send a reply. Use exactly one valid email value; arrays are not eligible for visitor replies.

3. When a reply is sent

A new submission needs an enabled reply, a successful Turnstile check for that form and website, a single valid email address, explicit consent and available sending allowance. A blocked reply does not reject an otherwise valid submission: it still reaches your inbox and owner notification workflow.

Spam and owner test submissions do not trigger visitor replies. Restoring a held message does not send a late confirmation. Previously received submissions are not backfilled when you enable replies.

Each queued reply keeps its saved subject, message and reply address. Editing or pausing the reply cancels earlier replies that are still waiting. Disabling Turnstile, pausing the form or losing the verified reply address also prevents queued replies from being sent. A send already in progress may finish. Replies waiting more than 24 hours are cancelled.

Use an idempotency key for retries of the same form submission. Duplicate submissions with the same key and data reuse the original result and do not create another confirmation.

4. Limits and unsubscribes

The service also reserves a maximum of 10,000 visitor replies per day across workspaces. Hour and day windows start with their first reserved reply. Addresses are compared after trimming and lowercasing; different email aliases remain different addresses.

Allowances are reserved when a reply enters the durable delivery queue. Failed, cancelled or deleted messages do not refund them. Owner notifications use their existing delivery path and do not consume these visitor reply allowances.

Every visitor reply includes a private preference link, valid for 90 days. Opening it displays a confirmation page; pressing Stop automatic visitor replies turns off these emails for that address across Form Koi. This preference remains in effect after the link expires and after a form or submission is deleted. It does not turn off account emails or form-owner notifications. Confirmed bounces and complaints also suppress sending.

5. Check the result

Open a submission’s Email delivery panel to see the visitor reply decision: queued, missing consent, spam, opted out or allowance reached. A queued decision records selection, not successful delivery. Each owner notification and visitor reply has a separate delivery status and attempt history.

Form Koi retries explicit provider throttling through the queue, up to eight attempts and within the 24-hour sending window. If the provider may have accepted an email but confirmation is missing, the status becomes Uncertain. Visitor replies cannot be manually resent; this avoids sending another message when the first may already be in the visitor’s inbox.

“Accepted by email service” is distinct from delivery to a receiving mail server, inbox placement or a read receipt. In staging, accepted means stored in the isolated test email sink.