> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ub.bitbros.in/llms.txt
> Use this file to discover all available pages before exploring further.

# September 2026

> What's new in urBackend — new features, improvements, and fixes.

<Update label="2026-09-14" description="Week of 2026-09-08–2026-09-14" tags={["Feature", "Fix"]}>
  ## New features

  * **`replyTo` on transactional mail** — `POST /mail/send` and `POST /mail/send/batch` now accept an optional `replyTo` field (a single address or an array of addresses). When set, replies from recipients route to those addresses instead of your verified `from` sender. Available in the REST API, TypeScript SDK (`mail.send()` / `mail.sendBatch()`), and Python SDK. See [Send mail](/api-reference/mail/send) and [Mail SDK](/sdk/mail). (by [@yash-pouranik](https://github.com/yash-pouranik) in [#402](https://github.com/geturbackend/urbackend/pull/402))

  ## Bug fixes

  * **Empty mail bodies are now rejected up-front** — Mail requests without any content (both `html` and `text` empty or whitespace) now fail validation with a `400` before hitting the mail queue, instead of enqueuing an empty message. Whitespace-only subjects are also rejected. See [Send mail](/api-reference/mail/send). (by [@yash-pouranik](https://github.com/yash-pouranik) in [#402](https://github.com/geturbackend/urbackend/pull/402))
</Update>


## Related topics

- [July 2026](/changelog/july-2026.md)
- [August 2026](/changelog/august-2026.md)
- [June 2026](/changelog/june-2026.md)
- [April 2026](/changelog/april-2026.md)