Release v4.9.0

What's Changed

• Add missing Total field in temporary failure stats by @WilliamRay in #298
• Allow setting preferred reply method to mailing lists by @skynexus in #302
• feat: added Send Time Optimization (STO) param by @cjyang0117 in #304

New Contributors

• @WilliamRay made their first contribution in #298
• @skynexus made their first contribution in #302
• @cjyang0117 made their first contribution in #304

Full Changelog: v4.8.2...v4.9.0