added cname records for smtp2go

nixos/modules/networking/dmz_services/zones/kun.is.nix

@@ -9,7 +9,7 @@ in
   SOA = {
     nameServer = "ns1";
     adminEmail = "webmaster@kun.is";
-    serial = 2024011401;
+    serial = 2024021702;
   };
 
   NS = [
@@ -60,5 +60,18 @@ in
       AAAA = [ cfg.dmz.ipv6.router ];
     };
 
+#for SMTP2GO to be able send emails from kun.is domain
+    em670271 = {
+      CNAME = ["return.smtp2go.net."];
+    };
+
+    "s670271._domainkey" = {
+      CNAME = ["dkim.smtp2go.net."];
+    };
+
+    link = {
+      CNAME = ["track.smtp2go.net."];
+    };
+
   };
 }