Quickstart

You can set up Sendpository yourself: no CLI, coding agent, or support call is required. You need access to your account inbox and a server-side application or terminal. You only need DNS access when sending from your own domain.

1. Create an account

Sign up at /signup. You land on Get started. Open the confirmation email and click its link, then return to Get started. If it did not arrive, check spam and use Resend in the dashboard banner. You can explore and create a key before confirming, but you cannot send yet. Google accounts with a verified Google-hosted mailbox do not need this extra step.

2. Verify your sending domain

Email providers only trust mail from a domain that has vouched for the sender. That's what verification does.

Go to Domains → Add domain and enter a subdomain you control, for example mail.yourdomain.com.

You'll be shown four DNS records:

Publish the displayed records at your DNS provider (Cloudflare, Route 53, GoDaddy, or wherever your DNS is hosted), then press Verify. Copy the account-specific values; do not copy an example DKIM key from documentation.

Do not replace existing apex MX/SPF records. If DMARC already exists, leave it in place rather than adding a second record.

Once SPF, DKIM, and the Return-Path MX resolve, the domain flips to Verified and you can send. DMARC is recommended, not a verification blocker. See DNS troubleshooting if it stays pending.

3. Create an API key

Use Create an API key on Get started, or go to API keys → Create API key and give it a name like development. Use a sending-only key for your app.

SENDPOSITORY_API_KEY=sp_your_api_key

Add .env to .gitignore before saving the key. On your hosting platform, add it to server-side secret/environment settings and restart or redeploy. Never use a NEXT_PUBLIC_ or VITE_ prefix or place the key in browser/mobile code. Your frontend calls your backend; your backend calls Sendpository.

A .env file is not automatically loaded by a shell or most language runtimes. For the terminal examples below, load the key without saving it in shell history:

printf 'Paste your API key (hidden): '
IFS= read -r -s SENDPOSITORY_API_KEY
printf '\n'
export SENDPOSITORY_API_KEY

On Windows, use a Bash terminal such as WSL/Git Bash for this command, or your application framework's server-side environment configuration.

4. Send your first email

Replace From with an address on your exact verified domain (or the sandbox address, if Get started shows one). Replace To with your own inbox for this test. The public API base is https://api.sendpository.com/v1; self-hosted/staging deployments should use the API base displayed on their Get started page.

curl --fail-with-body --max-time 15 -X POST https://api.sendpository.com/v1/emails \
  -H "Authorization: Bearer $SENDPOSITORY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "Acme <hello@mail.yourdomain.com>",
    "to": ["you@example.com"],
    "subject": "My first email",
    "html": "<p>It works.</p>"
  }'

A success looks like this:

{ "id": "d67e39ed-96be-4b35-ab22-853163d92c92" }

That id means the message was accepted, not that it reached an inbox. Store it to find the message under Emails and inspect its delivery timeline.

From your application

npm install sendpository

import { Sendpository } from "sendpository";

if (!process.env.SENDPOSITORY_API_KEY) throw new Error("Set SENDPOSITORY_API_KEY first.");
const sendpository = new Sendpository(process.env.SENDPOSITORY_API_KEY);

const { id } = await sendpository.emails.send({
  from: "Acme <hello@mail.yourdomain.com>",
  to: ["you@example.com"],
  subject: "My first email",
  html: "<p>It works.</p>",
});

console.log(id);

const res = await fetch("https://api.sendpository.com/v1/emails", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.SENDPOSITORY_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    from: "Acme <hello@mail.yourdomain.com>",
    to: ["you@example.com"],
    subject: "My first email",
    html: "<p>It works.</p>",
  }),
});

const data = await res.json();
if (!res.ok) throw new Error(`${data.error.type}: ${data.error.message}`);

console.log(data.id);

5. See what happened

Every message appears in Emails, with its current status.

Open one to see its full timeline - queued, sent, delivered, opened, and any bounce detail:

If it didn't work

Check the error type in the JSON response before changing your setup.

authentication_error

Check that the full key is loaded in the same process running the example. A key prefix ending in ... is a dashboard label, not a working credential. Never post your key in a support message.

rate_limit_exceeded

Wait for the seconds in the Retry-After header. Running every language example in quick succession can use the plan's short burst allowance. On retries, reuse an idempotency key for the same logical message.

domain_not_verified

The domain in your from address is not verified on your account. The from domain must match a domain in Domains exactly - hello@yourdomain.com will not send on a domain verified as mail.yourdomain.com. They are different domains as far as DNS is concerned.

email_not_verified

Your own account address has not been confirmed. Check your inbox for the confirmation email from signup, or resend it from the banner on the dashboard. You can explore everything without confirming, but you cannot send.

It says Sent but nothing arrived

Open the message in Emails and read its timeline. Three common causes:

• It went to spam. New sending domains have no reputation yet. Check the spam folder, and recheck domain authentication.
• It bounced. The timeline shows the receiving server's reason verbatim. A hard bounce also adds the address to your suppression list, so a second send to it is refused on purpose.
• The recipient domain rejected it silently. Rare, and the timeline will show delivered with nothing after it.

What next

Before production, verify your own domain, use a separate production key, handle typed errors and idempotent retries, and verify webhook signatures. Monitor your daily/monthly allowance under Settings → Plan. No dashboard send button installs code in your project: keep the send call in an authenticated server-side handler.