Resend event: email.scheduled, you still have a cancel window

TL;DR

If the user cancels, edits the content, or the underlying data changes before send time, cancel or update the scheduled email through the API.

Steps

1. Record the scheduled send time against data.email_id so your system knows the message is pending, not sent.
2. If the user cancels, edits the content, or the underlying data changes before send time, cancel or update the scheduled email through the API. This event is your reminder that the window is open.
3. When the send time arrives, expect email.sent to follow, then the rest of the delivery events.
4. Treating scheduled as sent in your UI or analytics. The recipient has seen nothing, and the email may still be canceled. The other trap is forgetting the queue exists: scheduled emails that outlive their context (a canceled order, a changed price) go out stale unless something watches this state.

When to use

You are seeing this: The email is scheduled to be sent. Use this skill when you run into "Resend event: email.scheduled, you still have a cancel window".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Resend's event reference says email.scheduled occurs whenever the email is scheduled to be sent. Verified live at https://resend.com/docs/webhooks/event-types.