Hosted forms

Everything else in these docs assumes you have a server for the library to run on. Hosted forms are for when you don’t: static sites, landing pages, docs, portfolios — anything that’s just HTML. Point a plain <form> at a Postboi endpoint and submissions arrive in your inbox as the same tidy email the library renders. No backend, no JavaScript, no npm install.

Create a form

In the dashboard, create a form: give it a name, pick which team member’s inbox receives submissions, and you get an endpoint URL like https://postboi.email/f/form_k3v9x2m1p8q4.

Submissions can only be delivered to a team member’s sign-in email — an address verified at sign-in (magic link or SSO), so a public endpoint can never be pointed at someone else’s inbox. If that member leaves the team, the form stops delivering until you point it at a current member.

The HTML

<form action="https://postboi.email/f/form_k3v9x2m1p8q4" method="POST">
	<input name="name" placeholder="Your name" required>
	<input name="email" type="email" placeholder="Your email" required>
	<textarea name="message" placeholder="Your message" required></textarea>

	<!-- honeypot: hidden from humans; bots fill it and get dropped -->
	<input name="🍯" style="position:absolute;left:-9999px;height:0;width:0;opacity:0"
		tabindex="-1" autocomplete="off" aria-hidden="true">

	<button>Send</button>
</form>

<form action="https://postboi.email/f/form_k3v9x2m1p8q4" method="POST">
	<input name="name" placeholder="Your name" required>
	<input name="email" type="email" placeholder="Your email" required>
	<textarea name="message" placeholder="Your message" required></textarea>

	<!-- honeypot: hidden from humans; bots fill it and get dropped -->
	<input name="🍯" style="position:absolute;left:-9999px;height:0;width:0;opacity:0"
		tabindex="-1" autocomplete="off" aria-hidden="true">

	<button>Send</button>
</form>

That’s the whole integration. On submit, the visitor lands on a hosted thank-you page — or set a redirect URL (https) on the form in the dashboard to send them back to your own site.

The email arrives with fields rendered as a table, and an email field is automatically used as the Reply-To — hitting Reply in your inbox goes straight back to the sender. File inputs (<input type="file"> with enctype="multipart/form-data") become attachments, up to 5 MB per submission.

Special fields

The endpoint speaks the library’s FormData dialect:

<input type="hidden" name="_subject" value="New enquiry from the pricing page">
<input name="contact→name" placeholder="Your name">
<input name="contact→email" type="email" placeholder="Your email">
<textarea name="details→message"></textarea>

<input type="hidden" name="_subject" value="New enquiry from the pricing page">
<input name="contact→name" placeholder="Your name">
<input name="contact→email" type="email" placeholder="Your email">
<textarea name="details→message"></textarea>

_to, _from, _cc and _bcc are ignored — the recipient is fixed by the form’s configuration, so a bot can’t repoint the mail.

Spam protection

Two layers, same as the library’s spam protection:

• Honeypot — include the hidden 🍯 field and bot submissions are silently dropped. The bot even receives a success response, so it learns nothing.
• Managed captcha — enable Require captcha on the form and add the captcha <script> tag (from the dashboard) to the page. Postboi renders an invisible Turnstile challenge and verifies every submission server-side. No Cloudflare account needed.

Endpoints are also rate-limited per form — 10 submissions a minute, 500 a day — on top of your plan’s limits, so a bot can’t drain your quota (or your overage bill) through a public URL.

Posting with fetch

Prefer to stay on the page? Ask for JSON and you get { ok: true } instead of a redirect (CORS is open — static sites post from their own origins):

const response = await fetch(form.action, {
	method: "POST",
	body: new FormData(form),
	headers: { accept: "application/json" },
})
const result = await response.json() // { ok: true, id: "msg_…" }

const response = await fetch(form.action, {
	method: "POST",
	body: new FormData(form),
	headers: { accept: "application/json" },
})
const result = await response.json() // { ok: true, id: "msg_…" }

A JSON request body works too — POST with content-type: application/json and a flat object of fields.

Errors come back as { ok: false, code, message } with a matching HTTP status:

Notes

• Form submissions are ordinary sends: they appear in the dashboard’s message log and count towards your plan’s volume — the free tier’s 3,000/mo covers a lot of contact form.
• Pause a form from the dashboard and its endpoint stops accepting immediately (410); resume it any time. Deleting a form kills the URL for good.
• If you do have a server, the library’s FormData handling gives you the same email with more control — and on SvelteKit the whole thing is a one-line form action.