diff --git a/nki-personal-do/configuration.nix b/nki-personal-do/configuration.nix
index f5d0e9d..923cad6 100644
--- a/nki-personal-do/configuration.nix
+++ b/nki-personal-do/configuration.nix
@@ -74,7 +74,7 @@
   cloud.mail = {
     enable = true;
     debug = true;
-    local_ip = "178.128.135.11"; # resolved from mx1.nkagami.me
+    local_ip = (builtins.elemAt config.networking.interfaces.eth0.ipv4.addresses 0).address;
     tls.certFile = "${config.cloud.traefik.certsDumper.destination}/${config.cloud.mail.hostname}/certificate.crt";
     tls.keyFile = "${config.cloud.traefik.certsDumper.destination}/${config.cloud.mail.hostname}/privatekey.key";
     usersFile = config.sops.secrets.mail-users.path;