I always make up some impossible domains like domain.tmptest
Otherwise you're one DNS "misconfiguration" away from sending dev logs and auth tokens to some random server.
> Since at least February 2020, Microsoft's Autodiscover service has incorrectly routed the IANA-reserved example.com to Sumitomo Electric Industries' mail servers at sei.co.jp, potentially sending test credentials there.
"Aha, the defective trucks only cause injuries to people who have their hands on the wheel at highway speeds, but I've never bothered holding the wheel at high speed, I just YOLO so I wouldn't be affected"
If people had used IANA's reserved TLDs they too would be unaffected because although Windows will stupidly try to talk to for example autodiscover.example that can't exist by policy and so the attempt will always fail.
I always use the ISO-3166 "user-assigned" 2-letter codes (AA, QM-QZ, XA-XZ, ZZ), with the theory being that ISO-3166 Maintenance Agency getting international consensus to move those codes back to regular country codes will take longer than the heat death of the universe, so using them for internal domains is probably safe.
It is reserved by ICANN since 2024-07-29.
https://en.wikipedia.org/wiki/.internal https://www.ietf.org/archive/id/draft-davies-internal-tld-00...
https://www.akamai.com/blog/security/autodiscovering-the-gre...
According to it, it seems that if someone registers autodiscover.com then example.com lacking autodiscover.example.com will make Outlook try checking if autodiscover.com has an entry.
It's just a braindead system.
Source: I'm on the board of dotMeow and wrote the financial plan