yes possible, but setting a reverse dns is the least small thing a vendor could do.
I just post my observations ...
regards
It is a valid observation, however I wouldn't expect it unless they were sending mail directly from the machine. It appears they're using MSFT for their email, so probably not the case. I think it is more unusual they have a private domain registration yet they aren't hiding the site behind a reverse proxy, i.e. Cloudflare.
FYI, my CN partner investigated and explained the whole workflow:
1) the ASIC chips and PCBs (main / hash boards) are produced by a well known high-tech factory in Shenzhen area;
2) the DaYun manufacturer (most likely based in NingBo) is a very small company just managed to buy and assemble the raw material, develop firmware (maybe...) and distribute the end product to the myriad of vendors mostly located (again) in Shenzhen...
3) the vendors are the only "official" distribution channel and they all signed an agreement with DaYun to not unveil their identity!
Interesting. Thank you for sharing this =)