Yeh, I was the same. If you do a DNS lookup for adguard.com it will show you the same address.
"The field has the following fields SPF:
v = spf1 + a + mx + ip4: 91.239.27.250/32 + ip4: 91.239.27.200/32 + ip4: 91.239.26.2/32 + ip4: 91.239.27.205/32 + ip4: 91.239.27.206/32 + ip4: 185.22.60.101/32 + ip4: 185.22.60.129/32 + ip4: 91.239.27.162/32 + ip4: 91.239.26.167/32 + ip4: 91.239.26.15/32 + ip4: 185.22.60.23/32 + i "" p4 : 104.131.4.201/32 include: _spf.google.com include: spf.mandrillapp.com include: mailgun.org include: sendgrid.net ~ all "