diff --git a/nix/sources.json b/nix/sources.json
index c6f1041..92e90a3 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -5,10 +5,10 @@
         "homepage": "https://github.com/NixOS/nixpkgs",
         "owner": "NixOS",
         "repo": "nixpkgs-channels",
-        "rev": "29eddfc36d720dcc4822581175217543b387b1e8",
-        "sha256": "1gqv2m7plkladd3va664xyqb962pqs4pizzibvkm1nh0f4rfpxvy",
+        "rev": "274831839c4f2622019a35d773d4ee588a08c311",
+        "sha256": "1dn0cv8ciq83c75hjqlqljjmsns60wqyijx9hzm3j8jvfxm4gzgk",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs-channels/archive/29eddfc36d720dcc4822581175217543b387b1e8.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs-channels/archive/274831839c4f2622019a35d773d4ee588a08c311.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "nixpkgs-unstable": {
@@ -17,10 +17,10 @@
         "homepage": "https://github.com/NixOS/nixpkgs",
         "owner": "NixOS",
         "repo": "nixpkgs-channels",
-        "rev": "fce7562cf46727fdaf801b232116bc9ce0512049",
-        "sha256": "14rvi69ji61x3z88vbn17rg5vxrnw2wbnanxb7y0qzyqrj7spapx",
+        "rev": "5717d9d2f7ca0662291910c52f1d7b95b568fec2",
+        "sha256": "17gxd2f622pyss3r6cjngdav6wzdbr31d7bqx9z2lawxg47mmk1l",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs-channels/archive/fce7562cf46727fdaf801b232116bc9ce0512049.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs-channels/archive/5717d9d2f7ca0662291910c52f1d7b95b568fec2.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     }
 }
diff --git a/tests/clamav.nix b/tests/clamav.nix
index 05cb30c..c641622 100644
--- a/tests/clamav.nix
+++ b/tests/clamav.nix
@@ -16,8 +16,8 @@
 
 { pkgs ? import <nixpkgs> {}}:
 
-import (pkgs.path + "/nixos/tests/make-test.nix") {
-
+pkgs.nixosTest {
+  name = "clamav";
   nodes = {
     server = { config, pkgs, lib, ... }:
       let
@@ -73,7 +73,6 @@ import (pkgs.path + "/nixos/tests/make-test.nix") {
 
             mailserver = {
               enable = true;
-              debug = true;
               fqdn = "mail.example.com";
               domains = [ "example.com" "example2.com" ];
               virusScanning = true;
@@ -194,52 +193,56 @@ import (pkgs.path + "/nixos/tests/make-test.nix") {
 
   testScript = { nodes, ... }:
       ''
-      startAll;
+      start_all()
 
-      $server->waitForUnit("multi-user.target");
-      $client->waitForUnit("multi-user.target");
+      server.wait_for_unit("multi-user.target")
+      client.wait_for_unit("multi-user.target")
 
       # TODO put this blocking into the systemd units? I am not sure if rspamd already waits for the clamd socket.
-      $server->waitUntilSucceeds("timeout 1 ${nodes.server.pkgs.netcat}/bin/nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ \$? -eq 124 ]");
-      $server->waitUntilSucceeds("timeout 1 ${nodes.server.pkgs.netcat}/bin/nc -U /run/clamav/clamd.ctl < /dev/null; [ \$? -eq 124 ]");
+      server.wait_until_succeeds(
+          "timeout 1 ${nodes.server.pkgs.netcat}/bin/nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
+      )
+      server.wait_until_succeeds(
+          "timeout 1 ${nodes.server.pkgs.netcat}/bin/nc -U /run/clamav/clamd.ctl < /dev/null; [ $? -eq 124 ]"
+      )
 
-      $client->execute("cp -p /etc/root/.* ~/");
-      $client->succeed("mkdir -p ~/mail");
-      $client->succeed("ls -la ~/ >&2");
-      $client->succeed("cat ~/.fetchmailrc >&2");
-      $client->succeed("cat ~/.procmailrc >&2");
-      $client->succeed("cat ~/.msmtprc >&2");
+      client.execute("cp -p /etc/root/.* ~/")
+      client.succeed("mkdir -p ~/mail")
+      client.succeed("ls -la ~/ >&2")
+      client.succeed("cat ~/.fetchmailrc >&2")
+      client.succeed("cat ~/.procmailrc >&2")
+      client.succeed("cat ~/.msmtprc >&2")
 
       # fetchmail returns EXIT_CODE 1 when no new mail
-      $client->succeed("fetchmail --nosslcertck -v || [ \$? -eq 1 ] >&2");
+      client.succeed("fetchmail --nosslcertck -v || [ $? -eq 1 ] >&2")
 
       # Verify that mail can be sent and received before testing virus scanner
-      $client->execute("rm ~/mail/*");
-      $client->succeed("msmtp -a user2 user1\@example.com < /etc/root/safe-email >&2");
+      client.execute("rm ~/mail/*")
+      client.succeed("msmtp -a user2 user1@example.com < /etc/root/safe-email >&2")
       # give the mail server some time to process the mail
-      $server->waitUntilFails('[ "$(postqueue -p)" != "Mail queue is empty" ]');
-      $client->execute("rm ~/mail/*");
+      server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
+      client.execute("rm ~/mail/*")
       # fetchmail returns EXIT_CODE 0 when it retrieves mail
-      $client->succeed("fetchmail --nosslcertck -v >&2");
-      $client->execute("rm ~/mail/*");
+      client.succeed("fetchmail --nosslcertck -v >&2")
+      client.execute("rm ~/mail/*")
 
-      subtest "virus scan file", sub {
-          $server->succeed("clamdscan \$(readlink -f /etc/root/eicar.com.txt) | grep \"Txt\\.Malware\\.Agent-1787597 FOUND\" >&2");
-      };
+      with subtest("virus scan file"):
+          server.succeed(
+              'clamdscan $(readlink -f /etc/root/eicar.com.txt) | grep "Txt\\.Malware\\.Agent-1787597 FOUND" >&2'
+          )
 
-      subtest "virus scan email", sub {
-          $client->succeed("msmtp -a user2 user1\@example.com < /etc/root/virus-email 2>&1 | tee /dev/stderr | grep \"server message: 554 5\\.7\\.1\" >&2");
-          $server->succeed("journalctl -u rspamd | grep -i eicar");
+      with subtest("virus scan email"):
+          client.succeed(
+              'msmtp -a user2 user1\@example.com < /etc/root/virus-email 2>&1 | tee /dev/stderr | grep "server message: 554 5\\.7\\.1" >&2'
+          )
+          server.succeed("journalctl -u rspamd | grep -i eicar")
           # give the mail server some time to process the mail
-          $server->waitUntilFails('[ "$(postqueue -p)" != "Mail queue is empty" ]');
-      };
-
-      subtest "no warnings or errors", sub {
-          $server->fail("journalctl -u postfix | grep -i error >&2");
-          $server->fail("journalctl -u postfix | grep -i warning >&2");
-          $server->fail("journalctl -u dovecot2 | grep -i error >&2");
-          $server->fail("journalctl -u dovecot2 | grep -i warning >&2");
-      };
+          server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
 
+      with subtest("no warnings or errors"):
+          server.fail("journalctl -u postfix | grep -i error >&2")
+          server.fail("journalctl -u postfix | grep -i warning >&2")
+          server.fail("journalctl -u dovecot2 | grep -i error >&2")
+          server.fail("journalctl -u dovecot2 | grep -i warning >&2")
     '';
 }
diff --git a/tests/default.nix b/tests/default.nix
index 11b3843..1e1b67b 100644
--- a/tests/default.nix
+++ b/tests/default.nix
@@ -23,7 +23,7 @@ let
     test = pkgs.callPackage (./. + "/${testName}.nix") { };
   in {
     "name"= builtins.replaceStrings ["." "-"] ["_" "_"] release;
-    "value"= test { inherit pkgs; };
+    "value"= test;
   };
 
   releaseNames = [
diff --git a/tests/extern.nix b/tests/extern.nix
index 343c458..f619c00 100644
--- a/tests/extern.nix
+++ b/tests/extern.nix
@@ -16,8 +16,8 @@
 
 { pkgs ? import <nixpkgs> {}}:
 
-import (pkgs.path + "/nixos/tests/make-test.nix") {
-
+pkgs.nixosTest {
+  name = "extern";
   nodes = {
     server = { config, pkgs, ... }:
         {
@@ -282,137 +282,144 @@ import (pkgs.path + "/nixos/tests/make-test.nix") {
 
   testScript = { nodes, ... }:
       ''
-      startAll;
+      start_all()
 
-      $server->waitForUnit("multi-user.target");
-      $client->waitForUnit("multi-user.target");
+      server.wait_for_unit("multi-user.target")
+      client.wait_for_unit("multi-user.target")
 
       # TODO put this blocking into the systemd units?
-      $server->waitUntilSucceeds("timeout 1 ${nodes.server.pkgs.netcat}/bin/nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ \$? -eq 124 ]");
+      server.wait_until_succeeds(
+          "timeout 1 ${nodes.server.pkgs.netcat}/bin/nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
+      )
 
-      $client->execute("cp -p /etc/root/.* ~/");
-      $client->succeed("mkdir -p ~/mail");
-      $client->succeed("ls -la ~/ >&2");
-      $client->succeed("cat ~/.fetchmailrc >&2");
-      $client->succeed("cat ~/.procmailrc >&2");
-      $client->succeed("cat ~/.msmtprc >&2");
+      client.execute("cp -p /etc/root/.* ~/")
+      client.succeed("mkdir -p ~/mail")
+      client.succeed("ls -la ~/ >&2")
+      client.succeed("cat ~/.fetchmailrc >&2")
+      client.succeed("cat ~/.procmailrc >&2")
+      client.succeed("cat ~/.msmtprc >&2")
 
-      subtest "imap retrieving mail", sub {
+      with subtest("imap retrieving mail"):
           # fetchmail returns EXIT_CODE 1 when no new mail
-          $client->succeed("fetchmail --nosslcertck -v || [ \$? -eq 1 ] >&2");
-      };
+          client.succeed("fetchmail --nosslcertck -v || [ $? -eq 1 ] >&2")
 
-      subtest "submission port send mail", sub {
+      with subtest("submission port send mail"):
           # send email from user2 to user1
-          $client->succeed("msmtp -a test --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email1 >&2");
+          client.succeed(
+              "msmtp -a test --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email1 >&2"
+          )
           # give the mail server some time to process the mail
-          $server->waitUntilFails('[ "$(postqueue -p)" != "Mail queue is empty" ]');
-      };
+          server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
 
-      subtest "imap retrieving mail 2", sub {
-          $client->execute("rm ~/mail/*");
+      with subtest("imap retrieving mail 2"):
+          client.execute("rm ~/mail/*")
           # fetchmail returns EXIT_CODE 0 when it retrieves mail
-          $client->succeed("fetchmail --nosslcertck -v >&2");
-      };
+          client.succeed("fetchmail --nosslcertck -v >&2")
 
-      subtest "remove sensitive information on submission port", sub {
-        $client->succeed("cat ~/mail/* >&2");
-        ## make sure our IP is _not_ in the email header
-        $client->fail("grep-ip ~/mail/*");
-        $client->succeed("check-mail-id ~/mail/*");
-      };
+      with subtest("remove sensitive information on submission port"):
+          client.succeed("cat ~/mail/* >&2")
+          ## make sure our IP is _not_ in the email header
+          client.fail("grep-ip ~/mail/*")
+          client.succeed("check-mail-id ~/mail/*")
 
-      subtest "have correct fqdn as sender", sub {
-        $client->succeed("grep 'Received: from mail.example.com' ~/mail/*");
-      };
+      with subtest("have correct fqdn as sender"):
+          client.succeed("grep 'Received: from mail.example.com' ~/mail/*")
 
-      subtest "dkim has user-specified size", sub {
-        $server->succeed("openssl rsa -in /var/dkim/example.com.mail.key -text -noout | grep 'Private-Key: (1535 bit'");
-      };
+      with subtest("dkim has user-specified size"):
+          server.succeed(
+              "openssl rsa -in /var/dkim/example.com.mail.key -text -noout | grep 'Private-Key: (1535 bit'"
+          )
 
-      subtest "dkim singing, multiple domains", sub {
-          $client->execute("rm ~/mail/*");
+      with subtest("dkim singing, multiple domains"):
+          client.execute("rm ~/mail/*")
           # send email from user2 to user1
-          $client->succeed("msmtp -a test2 --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email2 >&2");
-          $server->waitUntilFails('[ "$(postqueue -p)" != "Mail queue is empty" ]');
+          client.succeed(
+              "msmtp -a test2 --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email2 >&2"
+          )
+          server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
           # fetchmail returns EXIT_CODE 0 when it retrieves mail
-          $client->succeed("fetchmail  --nosslcertck -v");
-          $client->succeed("cat ~/mail/* >&2");
+          client.succeed("fetchmail  --nosslcertck -v")
+          client.succeed("cat ~/mail/* >&2")
           # make sure it is dkim signed
-          $client->succeed("grep DKIM ~/mail/*");
-      };
+          client.succeed("grep DKIM ~/mail/*")
 
-      subtest "aliases", sub {
-          $client->execute("rm ~/mail/*");
+      with subtest("aliases"):
+          client.execute("rm ~/mail/*")
           # send email from chuck to postmaster
-          $client->succeed("msmtp -a test3 --tls=on --tls-certcheck=off --auth=on postmaster\@example.com < /etc/root/email2 >&2");
-          $server->waitUntilFails('[ "$(postqueue -p)" != "Mail queue is empty" ]');
+          client.succeed(
+              "msmtp -a test3 --tls=on --tls-certcheck=off --auth=on postmaster\@example.com < /etc/root/email2 >&2"
+          )
+          server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
           # fetchmail returns EXIT_CODE 0 when it retrieves mail
-          $client->succeed("fetchmail --nosslcertck -v");
-      };
+          client.succeed("fetchmail --nosslcertck -v")
 
-      subtest "catchAlls", sub {
-          $client->execute("rm ~/mail/*");
+      with subtest("catchAlls"):
+          client.execute("rm ~/mail/*")
           # send email from chuck to non exsitent account
-          $client->succeed("msmtp -a test3 --tls=on --tls-certcheck=off --auth=on lol\@example.com < /etc/root/email2 >&2");
-          $server->waitUntilFails('[ "$(postqueue -p)" != "Mail queue is empty" ]');
+          client.succeed(
+              "msmtp -a test3 --tls=on --tls-certcheck=off --auth=on lol\@example.com < /etc/root/email2 >&2"
+          )
+          server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
           # fetchmail returns EXIT_CODE 0 when it retrieves mail
-          $client->succeed("fetchmail --nosslcertck -v");
+          client.succeed("fetchmail --nosslcertck -v")
 
-          $client->execute("rm ~/mail/*");
+          client.execute("rm ~/mail/*")
           # send email from user1 to chuck
-          $client->succeed("msmtp -a test4 --tls=on --tls-certcheck=off --auth=on chuck\@example.com < /etc/root/email2 >&2");
-          $server->waitUntilFails('[ "$(postqueue -p)" != "Mail queue is empty" ]');
+          client.succeed(
+              "msmtp -a test4 --tls=on --tls-certcheck=off --auth=on chuck\@example.com < /etc/root/email2 >&2"
+          )
+          server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
           # fetchmail returns EXIT_CODE 1 when no new mail
           # if this succeeds, it means that user1 recieved the mail that was intended for chuck.
-          $client->fail("fetchmail --nosslcertck -v");
-      };
+          client.fail("fetchmail --nosslcertck -v")
 
-      subtest "extraVirtualAliases", sub {
-          $client->execute("rm ~/mail/*");
+      with subtest("extraVirtualAliases"):
+          client.execute("rm ~/mail/*")
           # send email from single-alias to user1
-          $client->succeed("msmtp -a test5 --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email4 >&2");
-          $server->waitUntilFails('[ "$(postqueue -p)" != "Mail queue is empty" ]');
+          client.succeed(
+              "msmtp -a test5 --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email4 >&2"
+          )
+          server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
           # fetchmail returns EXIT_CODE 0 when it retrieves mail
-          $client->succeed("fetchmail --nosslcertck -v");
+          client.succeed("fetchmail --nosslcertck -v")
 
-          $client->execute("rm ~/mail/*");
+          client.execute("rm ~/mail/*")
           # send email from user1 to multi-alias (user{1,2}@example.com)
-          $client->succeed("msmtp -a test --tls=on --tls-certcheck=off --auth=on multi-alias\@example.com < /etc/root/email5 >&2");
-          $server->waitUntilFails('[ "$(postqueue -p)" != "Mail queue is empty" ]');
+          client.succeed(
+              "msmtp -a test --tls=on --tls-certcheck=off --auth=on multi-alias\@example.com < /etc/root/email5 >&2"
+          )
+          server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
           # fetchmail returns EXIT_CODE 0 when it retrieves mail
-          $client->succeed("fetchmail --nosslcertck -v");
-      };
+          client.succeed("fetchmail --nosslcertck -v")
 
-      subtest "quota", sub {
-          $client->execute("rm ~/mail/*");
-          $client->execute("mv ~/.fetchmailRcLowQuota ~/.fetchmailrc");
+      with subtest("quota"):
+          client.execute("rm ~/mail/*")
+          client.execute("mv ~/.fetchmailRcLowQuota ~/.fetchmailrc")
 
-          $client->succeed("msmtp -a test3 --tls=on --tls-certcheck=off --auth=on lowquota\@example.com < /etc/root/email2 >&2");
-          $server->waitUntilFails('[ "$(postqueue -p)" != "Mail queue is empty" ]');
+          client.succeed(
+              "msmtp -a test3 --tls=on --tls-certcheck=off --auth=on lowquota\@example.com < /etc/root/email2 >&2"
+          )
+          server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
           # fetchmail returns EXIT_CODE 0 when it retrieves mail
-          $client->fail("fetchmail --nosslcertck -v");
+          client.fail("fetchmail --nosslcertck -v")
 
-      };
-
-      subtest "imap sieve junk trainer", sub {
+      with subtest("imap sieve junk trainer"):
           # send email from user2 to user1
-          $client->succeed("msmtp -a test --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email1 >&2");
+          client.succeed(
+              "msmtp -a test --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email1 >&2"
+          )
           # give the mail server some time to process the mail
-          $server->waitUntilFails('[ "$(postqueue -p)" != "Mail queue is empty" ]');
+          server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
 
-          $client->succeed("imap-mark-spam >&2");
-          $server->waitUntilSucceeds("journalctl -u dovecot2 | grep -i sa-learn-spam.sh >&2");
-          $client->succeed("imap-mark-ham >&2");
-          $server->waitUntilSucceeds("journalctl -u dovecot2 | grep -i sa-learn-ham.sh >&2");
-      };
-
-      subtest "no warnings or errors", sub {
-          $server->fail("journalctl -u postfix | grep -i error >&2");
-          $server->fail("journalctl -u postfix | grep -i warning >&2");
-          $server->fail("journalctl -u dovecot2 | grep -i error >&2");
-          $server->fail("journalctl -u dovecot2 | grep -i warning >&2");
-      };
+          client.succeed("imap-mark-spam >&2")
+          server.wait_until_succeeds("journalctl -u dovecot2 | grep -i sa-learn-spam.sh >&2")
+          client.succeed("imap-mark-ham >&2")
+          server.wait_until_succeeds("journalctl -u dovecot2 | grep -i sa-learn-ham.sh >&2")
 
+      with subtest("no warnings or errors"):
+          server.fail("journalctl -u postfix | grep -i error >&2")
+          server.fail("journalctl -u postfix | grep -i warning >&2")
+          server.fail("journalctl -u dovecot2 | grep -i error >&2")
+          server.fail("journalctl -u dovecot2 | grep -i warning >&2")
     '';
 }
diff --git a/tests/intern.nix b/tests/intern.nix
index f96643c..b4f42db 100644
--- a/tests/intern.nix
+++ b/tests/intern.nix
@@ -34,56 +34,57 @@ let
     '';
 
 in
-import (pkgs.path + "/nixos/tests/make-test.nix") {
+pkgs.nixosTest {
+  name = "intern";
+  nodes = {
+    machine = { config, pkgs, ... }: {
+      imports = [
+        ./../default.nix
+        ./lib/config.nix
+      ];
 
-  machine =
-    { config, pkgs, ... }:
-    {
-        imports = [
-            ./../default.nix
-            ./lib/config.nix
-        ];
+      virtualisation.memorySize = 1024;
 
-        virtualisation.memorySize = 1024;
+      mailserver = {
+        enable = true;
+        fqdn = "mail.example.com";
+        domains = [ "example.com" ];
 
-        mailserver = {
-          enable = true;
-          fqdn = "mail.example.com";
-          domains = [ "example.com" ];
-
-          loginAccounts = {
-              "user1@example.com" = {
-                  hashedPassword = "$6$/z4n8AQl6K$kiOkBTWlZfBd7PvF5GsJ8PmPgdZsFGN1jPGZufxxr60PoR0oUsrvzm2oQiflyz5ir9fFJ.d/zKm/NgLXNUsNX/";
-              };
-              "send-only@example.com" = {
-                  hashedPasswordFile = hashPassword "send-only";
-                  sendOnly = true;
-              };
+        loginAccounts = {
+          "user1@example.com" = {
+            hashedPassword = "$6$/z4n8AQl6K$kiOkBTWlZfBd7PvF5GsJ8PmPgdZsFGN1jPGZufxxr60PoR0oUsrvzm2oQiflyz5ir9fFJ.d/zKm/NgLXNUsNX/";
+          };
+          "send-only@example.com" = {
+            hashedPasswordFile = hashPassword "send-only";
+            sendOnly = true;
           };
-
-          vmailGroupName = "vmail";
-          vmailUID = 5000;
         };
+
+        vmailGroupName = "vmail";
+        vmailUID = 5000;
+      };
     };
+  };
+  testScript = ''
+    machine.start()
+    machine.wait_for_unit("multi-user.target")
 
-  testScript =
-    ''
-      $machine->start;
-      $machine->waitForUnit("multi-user.target");
+    with subtest("vmail gid is set correctly"):
+        machine.succeed("getent group vmail | grep 5000")
 
-      subtest "vmail gid is set correctly", sub {
-            $machine->succeed("getent group vmail | grep 5000");
-      };
+    with subtest("mail to send only accounts is rejected"):
+        machine.wait_for_open_port(25)
+        # TODO put this blocking into the systemd units
+        machine.wait_until_succeeds(
+            "timeout 1 ${pkgs.netcat}/bin/nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
+        )
+        machine.succeed(
+            "cat ${sendMail} | ${pkgs.netcat-gnu}/bin/nc localhost 25 | grep -q 'This account cannot receive emails'"
+        )
 
-      subtest "mail to send only accounts is rejected", sub {
-            $machine->waitForOpenPort(25);
-            # TODO put this blocking into the systemd units?
-            $machine->waitUntilSucceeds("timeout 1 ${pkgs.netcat}/bin/nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ \$? -eq 124 ]");
-            $machine->succeed("cat ${sendMail} | ${pkgs.netcat-gnu}/bin/nc localhost 25 | grep -q 'This account cannot receive emails'" );
-      };
-
-      subtest "rspamd controller serves web ui", sub {
-            $machine->succeed("${pkgs.curl}/bin/curl --unix-socket /run/rspamd/worker-controller.sock http://localhost/ | grep -q '<body>'" );
-      };
-    '';
+    with subtest("rspamd controller serves web ui"):
+        machine.succeed(
+            "${pkgs.curl}/bin/curl --unix-socket /run/rspamd/worker-controller.sock http://localhost/ | grep -q '<body>'"
+        )
+  '';
 }