Resend compatibility

API base URL: https://api.relayloft.com

Relayloft implements the part of Resend's API that sends email and reports on it, so Resend's SDKs work with its base URL. Resend's docs for those endpoints apply, with these differences. Moving over? See Switch from Resend.

Supported

• Emails: POST /emails, POST /emails/batch (strict and permissive), GET /emails/:id, GET /emails (after and before).
• Scheduled send: scheduled_at on send and batch, PATCH /emails/:id to reschedule, POST /emails/:id/cancel (resend.emails.update, resend.emails.cancel) and the email.scheduled event.
• Domains: create, get, list, verify, update, delete (resend.domains.*).
• Open and click tracking: open_tracking and click_tracking on a domain, the email.opened and email.clicked events, and last_event opened / clicked (see Tracking).
• API keys: create, list, update, delete (resend.apiKeys.*).
• Webhooks: create, get, list, update, delete, rotate the signing secret, and their events (list, get, replay, attempts).
• Suppressions: add, get, list, remove, and batch add and remove (resend.suppressions.*).
• Templates: create, get, list, update, delete, publish, duplicate (resend.templates.*), and sending with template. See Templates.
• Email metrics (GET /emails/metrics) and attachments with download links (resend.emails.attachments.*). See Reading emails.
• Idempotency keys, tags, attachments by content or URL, inline images, Svix-signed webhooks.

Management calls (domains, keys, webhooks, suppressions, templates) need a Full access key and act on that key's app. Every change is in your audit log, and your Owner is emailed when a key or webhook is created through the API.

Different

• 7 MB per email (Resend allows 40 MB).
• One sending region; other regions, enforced TLS and receiving are refused with a reason.
• Tracking goes through the shared host relayloft.us. Open tracking works as soon as the domain is verified; click tracking once support has approved your account (turning it on in the sandbox is a 422). A custom tracking subdomain (tracking_subdomain) is refused with a reason, so tracking_subdomain is always null.
• A new key without permission is Sending only.
• Removing a suppression that came from a spam complaint needs the header x-mailroom-confirm-complaint: yes (or the portal). Sending to someone who complained is the fastest way to hurt your deliverability.
• Rate-limit headers: ratelimit-limit and ratelimit-policy on responses to a valid key; retry-after on every 429.
• Timestamps are ISO 8601.
• scheduled_at accepts ISO 8601 and a fixed set of phrases (see Scheduling); anything else is a 422. Rescheduling and canceling need a Full access key. Test addresses can't be scheduled.

Not supported (yet)

• react on the wire (the Node SDK renders it to HTML before sending, so that works).
• Audiences, contacts, broadcasts, receiving email, SMTP.

Resend is a trademark of Resend, Inc. Relayloft is not affiliated with or endorsed by Resend; the name is used only to describe compatibility.