tse1-mm.cn.bing.net isn't a standalone website — it's an infrastructure subdomain owned by Microsoft that immediately redirects visitors to www.bing.com. So the question "is tse1-mm.cn.bing.net safe" really comes down to whether you trust Bing itself.
Looking at the technical signals, everything checks out: the SSL certificate is valid and issued by Microsoft, the connection uses modern encryption, and the site has proper browser protections against clickjacking and content injection. No blacklists or Google Safe Browsing flags exist. The hosting sits on Microsoft's own network block, which is exactly what you'd expect from one of their subdomains.
There aren't any tse1-mm.cn.bing.net reviews because there's nothing to review — it's a back-end redirector. If you somehow ended up here, you're being forwarded to Bing's homepage. No data is collected at this subdomain, and Microsoft's standard privacy terms cover the experience. The only notable oddity is that the subdomain's WHOIS record returns no match, but that's normal for subdomains under a large corporate domain like bing.net.
Bottom line: this is not a scam, not a phishing site, and not something to worry about. It's a legitimate part of Microsoft's search infrastructure. You can ignore the URL entirely and just enjoy Bing.