Update is-a-backend.dev.json

domains/reserved/is-a-backend.dev.json

@@ -20,6 +20,21 @@
         ],
 
         "TXT": [
+            {
+                "name": "*._domainkey",
+                "value": "v=DKIM1; p="
+            },
+
+            {
+                "name": "@",
+                "value": "v=spf1 -all"
+            },
+
+            {
+                "name": "_dmarc",
+                "value": "v=DMARC1; p=reject; sp=reject; adkim=s; aspf=s;"
+            },
+
             {
                 "name": "_github-pages-challenge-free-domains",
                 "value": "2b1d1bccb97af4e747c6f48dd903ff"