Cloudprint.cainiao.com is a subdomain of the Alibaba-owned logistics platform Cainiao, likely providing cloud-based printing services for shipping labels. Unlike standalone SaaS products, this service doesn't need a public-facing website: it redirects to Taobao's login system, which is where you'd authenticate. That's normal for enterprise tools integrated into a larger ecosystem.
The most important thing to know is that the domain itself is part of Alibaba, one of the world's largest e-commerce companies. That gives it a huge trust advantage over an unknown startup. But there are small red flags: the site lacks basic polish like a favicon, and it accepts outdated TLS protocols. For a login page, strong encryption matters.
If you're accessing this through an Alibaba or Taobao partner account, you're likely fine. Just be sure you're on the official login.taobao.com page after the redirect, and avoid using it on public Wi-Fi without a VPN. There aren't many independent reviews of this specific tool, but for internal business tools, that's not unusual.