Schedule an email
Use sendAt for a simple future send, and use an app-owned scheduler when you need more control.
For a simple send later today or this week, put sendAt on the message:
await email.send({
from: "Acme <hello@acme.com>",
to: "user@example.com",
subject: "Your trial ends tomorrow",
text: "Open your account to keep your work.",
sendAt: new Date(Date.now() + 60 * 60_000),
});The provider holds the email until that time. Email SDK does not keep a timer, run a cron job, or stay alive in the background.
Supported adapters
sendAt works with Resend, SendGrid, Mailgun, MailerSend, Brevo, Mailchimp Transactional, and SparkPost. Other adapters reject the message before sending.
Provider limits still apply. Several providers only accept schedules a few days ahead, so check the adapter page before using a long delay.
If your client has a fallback that cannot schedule, disable that route for this send:
await email.send(message, {
fallback: { adapters: [] },
});Email SDK checks the whole route before sending, so it will not silently hand a scheduled message to an adapter that would send it immediately.
When to use your own scheduler
Keep the schedule in your database and let a queue, workflow, or cron worker call email.send when you need:
- cancellation or rescheduling
- delays longer than the provider allows
- a record of pending and completed work
- retries that survive a server restart
- the freedom to switch providers before the send happens
A cron job is fine when it polls a durable outbox table. Do not rely on an in-memory timer because a deploy or crash will lose it.
Production send pipeline
Store delivery state and retries outside the core SDK.
Delivery capabilities
Compare scheduling, idempotency, and personalized delivery support.