Send email, and see where it lands.

KeelSend sends your transactional email over one API call and your campaigns to your lists, then measures inbox placement on real mailboxes.

Get startedHow it works
curl https://api.keelsend.com/v1/messages \
  -H "Authorization: Bearer ks_live_…" \
  -d '{ "from": "Acme <billing@mail.acme.com>",
        "to": "jane@example.com",
        "subject": "Your invoice",
        "html": "<p>Thanks for your order.</p>",
        "idempotency_key": "invoice-1042" }'
HTTP/1.1 202 Accepted

{
  "message_id": "…"
}

Transactional API

One call, one recipient: attachments, your own metadata echoed back in events, and an idempotency key so a retry never sends twice.

Campaigns

Lists, CSV import with address validation, merge tags, scheduling and a send rate you control, with one-click unsubscribe built in.

Placement, measured

Every campaign is sent alongside seed mailboxes at the major providers, so you see inbox, tab or spam, not just "delivered".

Your own domain

You send from a domain you own. We list the SPF, DKIM, DMARC and return-path records it needs and check them for you.

Reviewed senders only

Every account is reviewed before it can send to real recipients. No purchased lists, no cold outreach.

Hosted in the EU

Message bodies are kept 72 hours for debugging, then deleted; delivery events are kept 90 days.

staging