Upstream raises $3M to launch collaborative AI inbox backed by YC and Xavier Niel

Paris-based startup Upstream  today announced the general availability launch of its AI-native inbox platform, alongside a $3 million pre-seed funding round backed by Y Combinator, Connect Ventures, and more than 30 founders and operators from companies including Framer, Algolia, Asana, Alan, and Webflow. Following months in invite-only beta, Upstream is now publicly available, positioning itself as “the first inbox designed for humans and agents.” The company has rebuilt email infrastructure fr