diff --git a/systems/LoutreOS/configuration.nix b/systems/LoutreOS/configuration.nix
index b643360..77a4c9b 100644
--- a/systems/LoutreOS/configuration.nix
+++ b/systems/LoutreOS/configuration.nix
@@ -228,7 +228,18 @@
     };
   };
 
-  services.autossh.sessions = [ { extraArguments = "-N -R 0.0.0.0:2222:127.0.0.1:22 loutre@vps772619.ovh.net"; monitoringPort = 20000; name = "backup-ssh-reverse"; user = "autossh"; } ];
+  # Options explanations
+  # -N                              disable shell
+  # -R 0.0.0.0:2222:127.0.0.1:22    redirect SSH port on VPS server on port 2222
+  # -R 127.0.0.1:2525:127.0.0.1:25  redirect SMTP port on VPS port 2525
+  services.autossh.sessions = [
+    {
+      extraArguments = "-N -R 0.0.0.0:2222:127.0.0.1:22 -R 127.0.0.1:2525:127.0.0.1:25 loutre@vps772619.ovh.net";
+      monitoringPort = 20000;
+      name = "backup-ssh-reverse";
+      user = "autossh";
+    }
+  ];
 
   virtualisation.podman.enable = true;