- Add configuration setting for CAS protocol version. Contributed by Aurélien Grimpard. ([\#15816](https://github.com/matrix-org/synapse/issues/15816))
- Add configuration setting for CAS protocol version. Contributed by Aurélien Grimpard. ([\#15816](https://github.com/matrix-org/synapse/issues/15816))
- Suppress notifications from message edits per [MSC3958](https://github.com/matrix-org/matrix-spec-proposals/pull/3958). ([\#16113](https://github.com/matrix-org/synapse/issues/16113))
- Suppress notifications from message edits per [MSC3958](https://github.com/matrix-org/matrix-spec-proposals/pull/3958). ([\#16113](https://github.com/matrix-org/synapse/issues/16113))
-Return a `Retry-After` with `M_LIMIT_EXCEEDED` error responses. ([\#16136](https://github.com/matrix-org/synapse/issues/16136))
-Experimental support for [MSC4041](https://github.com/matrix-org/matrix-spec-proposals/pull/4041): return a `Retry-After`header with `M_LIMIT_EXCEEDED` error responses. ([\#16136](https://github.com/matrix-org/synapse/issues/16136))
- Add `last_seen_ts` to the [admin users API](https://matrix-org.github.io/synapse/latest/admin_api/user_admin_api.html). ([\#16218](https://github.com/matrix-org/synapse/issues/16218))
- Add `last_seen_ts` to the [admin users API](https://matrix-org.github.io/synapse/latest/admin_api/user_admin_api.html). ([\#16218](https://github.com/matrix-org/synapse/issues/16218))
- Improve resource usage when sending data to a large number of remote hosts that are marked as "down". ([\#16223](https://github.com/matrix-org/synapse/issues/16223))
- Improve resource usage when sending data to a large number of remote hosts that are marked as "down". ([\#16223](https://github.com/matrix-org/synapse/issues/16223))
