- A metric was added for emails sent by Synapse, broken down by type: `synapse_emails_sent_total`. Contributed by Remi Rampin. ([\#16881](https://github.com/element-hq/synapse/issues/16881)) - Do not send multiple concurrent requests for keys for the same server. ([\#16894](https://github.com/element-hq/synapse/issues/16894)) - Fix performance issue when joining very large rooms that can cause the server to lock up. Introduced in v1.100.0. ([\#16903](https://github.com/element-hq/synapse/issues/16903)) - Always prefer unthreaded receipt when >1 exist ([MSC4102](https://github.com/matrix-org/matrix-spec-proposals/pull/4102)). ([\#16927](https://github.com/element-hq/synapse/issues/16927)) - Fix a small typo in the Rooms section of the Admin API documentation. Contributed by @RainerZufall187. ([\#16857](https://github.com/element-hq/synapse/issues/16857)) - Don't invalidate the entire event cache when we purge history. ([\#16905](https://github.com/element-hq/synapse/issues/16905)) - Add experimental config option to not send device list updates for specific users. ([\#16909](https://github.com/element-hq/synapse/issues/16909)) - Fix incorrect docker hub link in release script. ([\#16910](https://github.com/element-hq/synapse/issues/16910)) * Bump attrs from 23.1.0 to 23.2.0. ([\#16899](https://github.com/element-hq/synapse/issues/16899)) * Bump bcrypt from 4.0.1 to 4.1.2. ([\#16900](https://github.com/element-hq/synapse/issues/16900)) * Bump pygithub from 2.1.1 to 2.2.0. ([\#16902](https://github.com/element-hq/synapse/issues/16902)) * Bump sentry-sdk from 1.40.0 to 1.40.3. ([\#16898](https://github.com/element-hq/synapse/issues/16898))