Email API: More Control Over Scheduled Sends

The Telnyx Email API now gives developers more control over scheduled emails. You can reschedule an existing message without recreating it, with improved validation to help prevent unintended sends.

What's new

• In-place rescheduling: Move an existing scheduled email to a new future delivery time using PATCH /v2/email_messages/{id}/schedule.
• Safer schedule validation: Invalid or past timestamps now return a 422 response instead of being converted into immediate sends.

Why it matters

Plans change after an email is scheduled. You can now update the delivery time of an existing scheduled message without canceling and rebuilding it.

The updated validation also makes scheduling behavior more predictable. If a new delivery time is invalid or already in the past, the request fails with a 422 response rather than causing the email to send immediately.

Getting started

Prerequisites

• A Telnyx account (free to create)
• An API key from API Keys in the Telnyx Portal

All requests use the production base URL https://api.telnyx.com/v2 and an Authorization header with the Bearer authentication scheme. Replace YOUR_API_KEY in your requests with your Telnyx API key.

Reschedule a scheduled email

Reschedule an existing scheduled email with PATCH /v2/email_messages/{id}/schedule, providing a new future ISO 8601 scheduled_at value. Missing, invalid, or non-future values return 422, and the message is not sent. If the message is no longer scheduled or processing has already started, the API returns 409.

Learn more in the Email API sending and scheduling documentation.