diff --git a/nixbld-etc-nixos/configuration.nix b/nixbld-etc-nixos/configuration.nix
index 6c23acc..a6b65d4 100644
--- a/nixbld-etc-nixos/configuration.nix
+++ b/nixbld-etc-nixos/configuration.nix
@@ -262,7 +262,7 @@ in
     };
     greTunnels.intl0 = {
       dev = netifWan;
-      remote = "5.78.16.0";
+      remote = "5.78.86.156";
       local = "94.190.212.123";
       ttl = 255;
       type = "tun";
@@ -353,7 +353,7 @@ in
   };
   services.strongswan-swanctl.swanctl.connections.intl = {
     local_addrs = [ "94.190.212.123" ];
-    remote_addrs = [ "5.78.16.0" ];
+    remote_addrs = [ "5.78.86.156" ];
     local.main = {
       auth = "pubkey";
       id = "fqdn:m-labs.hk";
@@ -367,7 +367,7 @@ in
     children.intl0 = {
       mode = "transport";
       ah_proposals = [ "sha256-curve25519" ];
-      remote_ts = [ "5.78.16.0[gre]" ];
+      remote_ts = [ "5.78.86.156[gre]" ];
       local_ts = [ "94.190.212.123[gre]" ];
       start_action = "start";
     };
@@ -1305,14 +1305,14 @@ in
     };
   };
 
-  environment.etc."postfix/sender_relay".text = ''
+  services.postfix.mapFiles.sender_relay = pkgs.writeText "sender_relay" ''
       m-labs-intl.com smtptun:
       * :
   '';
   systemd.services.postfix-rebuild-sender-relay = {
       description = "Postfix Rebuild Sender Dependent Relayhost Maps";
       serviceConfig = {
-        ExecStart = "${pkgs.postfix}/sbin/postmap /etc/postfix/sender_relay";
+        ExecStart = "${pkgs.postfix}/sbin/postmap /var/lib/postfix/conf/sender_relay";
       };
       wantedBy = [ "multi-user.target" ];
   };
@@ -1328,14 +1328,15 @@ in
   } // (import /etc/nixos/secret/email_settings.nix);
   services.postfix = {
     config = {
-      sender_dependent_relayhost_maps = "hash:/etc/postfix/sender_relay";
-      masterConfig.smtptun = {
-        type = "smtp";
-        command = "smtp";
-        args = "-o smtp_bind_address=10.47.3.2";
-      };
+      sender_dependent_relayhost_maps = "hash:/var/lib/postfix/conf/sender_relay";
+    };
+    masterConfig."smtptun" = {
+      type = "unix";
+      command = "smtp";
+      args = [ "-o" "smtp_bind_address=10.47.3.2" ];
     };
   };
+
   services.roundcube = {
     enable = true;
     hostName = "mail.m-labs.hk";
diff --git a/nixbld-etc-nixos/named/m-labs-intl.com b/nixbld-etc-nixos/named/m-labs-intl.com
index fdb5510..ac71b52 100644
--- a/nixbld-etc-nixos/named/m-labs-intl.com
+++ b/nixbld-etc-nixos/named/m-labs-intl.com
@@ -22,7 +22,7 @@ $TTL 7200
 ns						A		94.190.212.123
 ns						AAAA	2001:470:18:390::2
 
-mail					A		5.78.16.0
+mail					A		5.78.86.156
 mail._domainkey			IN	TXT	"v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDJVPuhSGXghO7ib8Em/Se3jfCCIJK5g4zn5pGZ3/e0I0f+zGHMuvwpjkAKf6eSmo/AAXEaco28pDi3qE5xfV512AJsORCfPoPFyNhLsj/qtri6hc5KVSWW0Ja3MSFBINDCaX78c7PXPY+3jJJGpwSBDLjdxj9AQwtfiCVlH4qE/QIDAQAB"
 _dmarc					TXT		"v=DMARC1; p=none"