Sending email

POST /emails sends one email. For per-recipient subjects, data and arguments in a single request, there's also Mail Send (v3); both go through the same delivery pipeline.

curl https://api.jumploon.com/emails \
  -H "Authorization: Bearer $JUMPLOON_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "Acme <hello@acme.com>",
    "to": ["ada@example.org"],
    "subject": "Your receipt",
    "html": "<p>Thanks for your order.</p>",
    "text": "Thanks for your order.",
    "tags": [{ "name": "type", "value": "receipt" }]
  }'

{ "id": "4ef9a417-02e9-4d39-ad75-9611e0fcc33c" }

Parameters

Field	Type	Description
`from`	string	Required. `hello@acme.com` or `Acme <hello@acme.com>`. The domain must be verified.
`to`	string or string[]	Required. Up to 50 addresses.
`subject`	string	Required unless a template supplies it.
`html`	string	HTML body.
`text`	string	Plain-text body. Send both `html` and `text` for the best deliverability.
`cc`, `bcc`	string or string[]	Copy recipients.
`reply_to`	string or string[]	Reply-To addresses.
`headers`	object	Extra headers, such as `{ "X-Entity-Ref-ID": "123" }`.
`attachments`	array	See Attachments.
`tags`	array	`{ name, value }` pairs, letters, digits, `_` and `-`. They appear in webhooks and can be used to filter activity and stats.
`scheduled_at`	string	Send later. See Scheduling.
`template`	object	`{ "id": "d-…", "variables": { … } }` to render a template.

Attachments

"attachments": [
  {
    "filename": "invoice-1042.pdf",
    "content": "JVBERi0xLjcKCjEgMCBvYmoK...",
    "content_type": "application/pdf"
  }
]

content is the file as a base64 string (or, in the Node SDK, a Buffer). Fetching attachments from a URL with path isn't supported: download the file yourself and pass its content.

To embed an image in the HTML, give it a content_id and reference it as <img src="cid:logo">.

Retrieve an email

curl https://api.jumploon.com/emails/<id> -H "Authorization: Bearer $JUMPLOON_API_KEY"

The response includes the recipients, subject, bodies and last_event, such as delivered or bounced. GET /emails lists recent emails.

Sandbox mode

To validate a request without sending anything (useful in CI), use the v3 API with sandbox mode:

"mail_settings": { "sandbox_mode": { "enable": true } }

The request is fully validated, including the sender's domain and your quota, and returns 200 instead of 202. Nothing is queued or delivered.

What happens after you send

The API validates the request, checks that the sender's domain is verified and that you're within your daily quota, and returns.
Each recipient becomes its own delivery. Suppressed addresses (earlier bounces, unsubscribes, spam reports) are dropped.
The message is DKIM-signed and delivered to the recipient's mail server.
Temporary failures are retried with increasing delays for up to 72 hours. Permanent failures become bounces and the address is suppressed.
Every step is recorded in Activity and sent to your webhooks.