Send an email

POST https://api.sushisend.com/v1/emails
Authorization: Bearer ssk_live_...
Content-Type: application/json

Body

{
  "from": "hello@yourdomain.com",
  "to": "user@example.com",
  "subject": "Welcome",
  "text": "Plain-text body here.",
  "html": "<p>HTML body here.</p>",
  "replyTo": "support@yourdomain.com"
}

• from must be on a verified sending domain.
• At least one of text or html is required.
• subject can’t contain \r or \n (header-injection protection).
• replyTo is optional.

Response

{
  "id": "01HRY3Z7Q9M7ABCDEF",
  "sesMessageId": "010201...",
  "status": "sent"
}

id is SushiSend’s message ID — use it to correlate webhook events. sesMessageId is the underlying provider ID.

Common errors

Status	error	Meaning
400	missing_from / missing_to / missing_subject	Required field missing.
400	invalid_from_email	from isn’t a valid email or contains CR/LF.
400	invalid_subject	Subject contains a newline.
401	unauthenticated	Missing / invalid Bearer token.
402	daily_quota_exceeded	Free plan 50/day cap hit.
402	monthly_quota_exceeded	Plan monthly cap hit.
403	recipient suppressed	Address is on your workspace’s suppression list.
502	send_failed	Downstream provider rejected the send.

Idempotency (roadmap)

Idempotency keys via the Idempotency-Key header are on the roadmap. Until they land, handle transient 5xx responses with an exponential-backoff retry and dedupe on your side.