I have been using cloudflare for more than a year, I can access my network domain and subdomains almost from everywhere without problem.
- However I have my email on GMX - German server and I can’t send any emails from there to my home (ubx.ro) with the error invalid domain. (from gmail, microsoft, yahoo it is fine, I get emails.)
- I try to scan my domain ubx.ro or nc.ubx.ro from this nextcloud security check tool from Germany https://scan.nextcloud.com, but again my domain is invalid.
- I have a friend who lives in Germany and he is on vodafone (land line) provider and my server doesn’t respond to ping. If he connects to mobile network, everything is fine. Also, if he connects to vpn, it is fine, he can connect. If he connects to an alias server name or direct to my ip, it is also fine.
Do you have any ideas? because something like that looks very strange to me.