Tencent Enterprise Email, from Tencent (founded 1998), builds on QQ Mail's technology with deep WeChat integration. The free tier supports 50 users, making it China's most widely used business email service.
NetEase Enterprise Email, operated by NetEase (founded 1997), powers over 500 million users via its 163 Mail platform. Offers custom domain business email, anti-spam, and office suite services.
Alibaba Enterprise Email, from Alibaba Cloud (founded 2009), integrates natively with DingTalk. Built on Alibaba Cloud's global infrastructure, offering custom domain email, office suite, and cloud management.