diff --git a/systems/x86_64-linux/mx/default.nix b/systems/x86_64-linux/mx/default.nix
index 493ee7a..3efb22c 100644
--- a/systems/x86_64-linux/mx/default.nix
+++ b/systems/x86_64-linux/mx/default.nix
@@ -118,6 +118,18 @@
       };
       wantedBy = [ "default.target" ];
     };
+  };
+
+  systemd.timers = {
+    check_boot = {
+      timerConfig = {
+        OnCalendar = "daily";
+      };
+      wantedBy = [ "timers.target" ];
+    };
+  };
+
+  systemd.services = {
     check_root = {
       serviceConfig = {
         Type = "oneshot";
@@ -128,7 +140,7 @@
             THRESHOLD=85
 
             if [ "$CURRENT" -gt "$THRESHOLD" ] ; then
-                ${pkgs.mailutils}/bin/mail -s '/ Disk Space Alert' harald << EOF
+                ${pkgs.mailutils}/bin/mail -s '/boot Disk Space Alert' harald << EOF
             Your root partition remaining free space is critically low. Used: $CURRENT%
             EOF
             fi
@@ -140,12 +152,6 @@
   };
 
   systemd.timers = {
-    check_boot = {
-      timerConfig = {
-        OnCalendar = "daily";
-      };
-      wantedBy = [ "timers.target" ];
-    };
     check_root = {
       timerConfig = {
         OnCalendar = "daily";
diff --git a/systems/x86_64-linux/mx/mailserver.nix b/systems/x86_64-linux/mx/mailserver.nix
index f934698..7dd0547 100644
--- a/systems/x86_64-linux/mx/mailserver.nix
+++ b/systems/x86_64-linux/mx/mailserver.nix
@@ -242,7 +242,8 @@
     hostName = "webmail.hoyer.xyz";
     plugins = [ "managesieve" ];
     extraConfig = ''
-      # SSL/TLS needed for authentication, so the fqdn must match the certificate
+      # starttls needed for authentication, so the fqdn required to match
+      # the certificate
       $config['smtp_server'] = "ssl://${config.mailserver.fqdn}:465";
       $config['smtp_user'] = "%u";
       $config['smtp_pass'] = "%p";
diff --git a/systems/x86_64-linux/mx/postgresql.nix b/systems/x86_64-linux/mx/postgresql.nix
index fac6f2b..584635f 100644
--- a/systems/x86_64-linux/mx/postgresql.nix
+++ b/systems/x86_64-linux/mx/postgresql.nix
@@ -8,33 +8,4 @@
   services.postgresql = {
     package = pkgs.postgresql_14;
   };
-
-  # Temporary: upgrade script for PostgreSQL 14 → 16 migration.
-  # After upgrading, change package above to postgresql_16 and remove this block.
-  environment.systemPackages = [
-    (
-      let
-        newPostgres = pkgs.postgresql_16;
-        cfg = config.services.postgresql;
-      in
-      pkgs.writeScriptBin "upgrade-pg-cluster" ''
-        set -eux
-        systemctl stop postgresql
-
-        export NEWDATA="/var/lib/postgresql/${newPostgres.psqlSchema}"
-        export NEWBIN="${newPostgres}/bin"
-        export OLDDATA="${cfg.dataDir}"
-        export OLDBIN="${cfg.finalPackage}/bin"
-
-        install -d -m 0700 -o postgres -g postgres "$NEWDATA"
-        cd "$NEWDATA"
-        sudo -u postgres "$NEWBIN/initdb" -D "$NEWDATA" ${lib.escapeShellArgs cfg.initdbArgs}
-
-        sudo -u postgres "$NEWBIN/pg_upgrade" \
-          --old-datadir "$OLDDATA" --new-datadir "$NEWDATA" \
-          --old-bindir "$OLDBIN" --new-bindir "$NEWBIN" \
-          "$@"
-      ''
-    )
-  ];
 }