mail: disable ipv6

hosts/knot/default.nix

@@ -95,11 +95,11 @@
           address = [ "217.115.12.65" "2a00:1328:e101:b01::1" ];
         } {
           id = "ns1.supersandro.de";
+          # IPv4 doesn't work because of nat
           address = [ /*"188.34.196.104"*/ "2a01:4f8:1c1c:1d38::1" ];
         } {
           id = "dns.serv.zentralwerk.org";
-          # IPv4 doesn't work because of nat
-          address = [ /*"172.20.73.2"*/ "2a00:8180:2c00:282:2::2" ];
+          address = [ "172.20.73.2" "2a00:8180:2c00:282:2::2" ];
         }
       ];
 

hosts/mail/default.nix

@@ -83,6 +83,8 @@
     vmailUserName = "vmail";
   };
 
+  networking.enableIPv6 = false; # mail is stuck in the 80s
+
   services = {
     backup = {
       enable = true;