SendCoop + Transactional email API
Send receipts, password resets, sign-in codes and other app emails from your own code or over SMTP, through the same sending domains, tracking and bounce handling as your campaigns.
- SMTP relay on smtp.sendcoop.com (ports 587 and 465) for WordPress, Laravel, Django, Nodemailer and any SMTP app
- HTML or text, or one of your saved templates with {{variables}}
- Attachments up to 10 MB, cc, bcc and reply-to
- Open and click tracking on your own tracking domain
- Batches of up to 50 messages and scheduled sends
- Idempotency keys, so retries never send twice
- Message log with a status timeline for every email
/api/v1/transactional/sendPOST/api/v1/transactional/batchPOSTsmtp.sendcoop.comSMTPtransactional.deliveredWebhookConnect Transactional email API in three steps
- STEP 1Verify your sending domain under Deliverability.
- STEP 2Create a named key under Integrations → API.
- STEP 3POST JSON to /api/v1/transactional/send with the key as a Bearer token, or point your app’s SMTP settings at smtp.sendcoop.com with the key as the password.
Host smtp.sendcoop.com
Port 587 (STARTTLS) or 465 (SSL/TLS)
Username sendcoop
Password YOUR_API_KEY
Limits 50 recipients, 15 MB per message
Headers X-SendCoop-Tags: receipt
X-SendCoop-Metadata: {"order_id": "1001"}
X-SendCoop-Track-Opens: false
X-SendCoop-Track-Clicks: false
X-SendCoop-Send-At: 2026-10-20T09:00:00ZMAIL_MAILER=smtp
MAIL_HOST=smtp.sendcoop.com
MAIL_PORT=587
MAIL_USERNAME=sendcoop
MAIL_PASSWORD=YOUR_API_KEY
MAIL_ENCRYPTION=tls
MAIL_FROM_ADDRESS=hello@yourdomain.comWhat people build with Transactional email API
Order receipts
Send a receipt from your checkout with the order details as variables in a saved template.
Password resets and sign-in codes
Fast, single emails from your app, with the result in the message log.
WordPress and app email over SMTP
Point WP Mail SMTP, Laravel, Django or any app at smtp.sendcoop.com and its emails show up in the same message log.
Delivery events in your app
Get transactional.delivered, .bounced and .opened webhooks to update your own records.
Do transactional emails use my sending credits?
Yes. Each recipient uses one credit, the same as a campaign email.
Are unsubscribed contacts skipped?
No. Unsubscribing stops marketing email only, so receipts and password resets still arrive. Addresses that hard-bounced or reported spam are skipped and shown as suppressed.
Can I send through SMTP instead?
Yes. Use host smtp.sendcoop.com, port 587 with STARTTLS or 465 with SSL/TLS, username sendcoop and any of your API keys as the password. Up to 50 recipients and 15 MB per message. Messages get the same checks as the API and appear in the message log marked SMTP.
Can I set tags or tracking over SMTP?
Yes, with optional headers: X-SendCoop-Tags (comma-separated), X-SendCoop-Metadata (a JSON object), X-SendCoop-Track-Opens and X-SendCoop-Track-Clicks (true or false) and X-SendCoop-Send-At (an ISO 8601 time up to 72 hours ahead). They are removed before the email is sent.
How long are messages kept?
The message log is kept for 90 days. Message content is removed after 7 days.
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