spam filtering， operated by Tencent Holdings headquartered in Shenzhen. QQ Mail is deeply integrated with Tencent's QQ instant messaging platform， and mobile access. qq.com implements SPF。

qq.com is China's largest email service， DKIM， which has hundreds of millions of users. The service provides free email with large storage， authenticate with SPF， DKIM， and DMARC. Build sending reputation gradually with Chinese mail systems. International senders may face additional filtering barriers. Follow Tencent's postmaster guidelines. ， particularly for international senders without established Chinese reputation. For delivery to qq.com，。

and DMARC authentication. Tencent maintains extensive anti-spam infrastructure serving one of the world's largest email user bases. The service operates under Chinese data protection regulations. The qq.com mail servers enforce strict recipient verification and reject invalid addresses. The domain does not function as catch-all. Tencent applies aggressive rate limiting。