Use case
Send Receipt and Invoice Emails with an Email API
Receipts and invoices need a dependable send path, repeat-safe retries, and a support trail when a customer asks what happened. NoticeAPI handles the email API side: templates, attachments over REST, idempotency, logs, and delivery events.
curl -X POST https://www.noticeapi.com/api/v1/email/send \
-H "Authorization: Bearer ntc_xxxxxxxxxxxxxxxxxxxx" \
-H "Idempotency-Key: invoice-1042" \
-H "Content-Type: application/json" \
-d '{
"from": "Acme Billing <[email protected]>",
"to": "[email protected]",
"subject": "Invoice #1042",
"html": "<p>Your invoice is attached.</p>",
"attachments": [
{ "filename": "invoice-1042.pdf", "content": "BASE64...", "contentType": "application/pdf" }
]
}'REST attachments
Attach PDFs and other supported documents through the REST send API.
Duplicate protection
Use order, invoice, or payment event ids as idempotency keys.
Stored bodies
Inspect sent subject, HTML, text, and delivery status later from the API or portal.
Billing event feedback
Use signed webhooks to update your app when a receipt is delivered, bounced, or suppressed.
How it works
From test send to production traffic.
Render the receipt
Build the receipt or invoice in your app and pass the customer-visible content to NoticeAPI.
Attach when needed
Use REST attachments for PDFs. SMTP relay does not support attachments today.
Retry safely
Use the invoice or payment event id as the idempotency key.
Support the customer
Look up the stored email and delivery timeline when someone says they did not receive it.
Trust
Receipts need an audit trail
NoticeAPI records the message body, recipient state, and delivery events so support can investigate receipt and invoice issues without guessing.
Implementation links
Build with the shipped docs.
FAQ
Questions developers ask before switching email.
Can I attach a PDF invoice?
Yes, through the REST send API. SMTP attachments are not supported today.
What idempotency key should I use?
Use a stable invoice id, order id, or billing event id so a retry cannot send a duplicate receipt.
Can support see what was sent?
Yes. Sent emails keep their subject, HTML, text, and delivery timeline.
Start free. Send production after your domain is ready.
Free includes 3,000 production emails per month, a 100/day production cap, and one verified sending domain.