The description already tells us that we have to look into the DNS information of jh2i.com. You can use a tool like [https://www.ultratools.com/tools/dnsLookupResult](https://www.ultratools.com/tools/dnsLookupResult) to check the different DNS Records. In the SPF Record (Sender Policy Framework, Email-Spoofing protection) we find the flag.
"flag{next_year_i_wont_use_spf}"	