# Nylas Python SDK v6.18.0

Source: https://developer.nylas.com/docs/changelogs/2026-10-01-nylas-python-v6-18-0/

## Added

- **Custom tracking hostnames.** `tracking_options` now accepts an optional `domain_name` so link and open tracking on message sends, scheduled sends, drafts, and [Transactional Send](/docs/v3/getting-started/transactional-send/) can use your own verified tracking domain instead of the Nylas default.
- **Contact metadata.** `Contact` requests and responses now support the `metadata` object and `metadata_pair` filtering, matching the metadata support already available on Events, Messages, and Drafts.
- **`messages.send_raw_mime()`** sends a raw RFC 822 MIME message through `POST /v3/grants/{grant_id}/messages/send?type=mime`, using the new `SendRawMimeRequest` model.