Schedule & cancel emails
Pass an RFC 3339 scheduled_at on POST /emails to queue a send for
the future. The email is created immediately with status: "scheduled" and goes out at the
scheduled time.
{ "from": "Acme <hi@acme.com>", "to": "user@example.com", "subject": "Reminder", "html": "<p>…</p>", "scheduled_at": "2026-09-01T09:00:00Z" }Reschedule
Section titled “Reschedule”PATCH /emails/{id} with a new scheduled_at moves a not-yet-sent email:
curl -X PATCH https://api.sendsignal.dev/emails/{id} \ -H "Authorization: Bearer ss_..." \ -H "Content-Type: application/json" \ -d '{"scheduled_at": "2026-09-02T09:00:00Z"}'Cancel
Section titled “Cancel”POST /emails/{id}/cancel cancels any email that hasn’t gone out yet; its status becomes
canceled and it never reaches the provider.
Suppression checks run again at send time, not just at enqueue: if a recipient bounces,
complains, or unsubscribes between scheduling and the send date, the scheduled email is
suppressed instead of sent (status suppressed, with an email.suppressed
event).