diff --git a/src/controller.php b/src/controller.php
index 1bf3de0..1cab399 100644
--- a/src/controller.php
+++ b/src/controller.php
@@ -18,25 +18,12 @@ abstract class Controller {
     function invoke(ImapClient $imapClient) {
     }
 
-    function if_invalid_redirect_to_random(User $user, array $config_domains) {
+    function validate_user(User $user, array $config_domains) {
         if ($user->isInvalid($config_domains)) {
-            $this->redirect_to_random($config_domains);
+            $this->viewHandler->invalid_input($config_domains);
             exit();
         }
     }
-
-    function redirect_to_random(array $domains) {
-        $wordLength = rand(3, 8);
-        $container = new PronounceableWord_DependencyInjectionContainer();
-        $generator = $container->getGenerator();
-        $word = $generator->generateWordOfGivenLength($wordLength);
-        $nr = rand(51, 91);
-        $name = $word . $nr;
-
-        $domain = $domains[array_rand($domains)];
-        $this->viewHandler->newAddress("$name@$domain");
-    }
-
 }
 
 class RedirectToAddressController extends Controller {
@@ -73,7 +60,7 @@ class DownloadEmailController extends Controller {
 
     function invoke(ImapClient $imapClient) {
         $user = User::parseDomain($this->address, $this->config_blocked_usernames);
-        $this->if_invalid_redirect_to_random($user, $this->config_domains);
+        $this->validate_user($user, $this->config_domains);
 
         $download_email_id = filter_var($this->email_id, FILTER_SANITIZE_NUMBER_INT);
         $full_email = $imapClient->load_one_email_fully($download_email_id, $user);
@@ -102,7 +89,7 @@ class DeleteEmailController extends Controller {
 
     function invoke(ImapClient $imapClient) {
         $user = User::parseDomain($this->address, $this->config_blocked_usernames);
-        $this->if_invalid_redirect_to_random($user, $this->config_domains);
+        $this->validate_user($user, $this->config_domains);
 
         $delete_email_id = filter_var($this->email_id, FILTER_SANITIZE_NUMBER_INT);
         if ($imapClient->delete_email($delete_email_id, $user)) {
@@ -121,7 +108,8 @@ class RedirectToRandomAddressController extends Controller {
     }
 
     function invoke(ImapClient $imapClient) {
-        $this->redirect_to_random($this->config_domains);
+        $address = User::get_random_address($this->config_domains);
+        $this->viewHandler->newAddress($address);
     }
 
 }
@@ -135,11 +123,10 @@ class DisplayEmailsController extends Controller {
         $this->config = $config;
     }
 
-
     function invoke(ImapClient $imapClient) {
         // print emails with html template
         $user = User::parseDomain($this->address, $this->config['blocked_usernames']);
-        $this->if_invalid_redirect_to_random($user, $this->config['domains']);
+        $this->validate_user($user, $this->config['domains']);
         $emails = $imapClient->get_emails($user);
 
         $this->viewHandler->displayEmails($emails, $this->config, $user);
diff --git a/src/json-api.php b/src/json-api.php
index 30a7c16..f6fc3c2 100644
--- a/src/json-api.php
+++ b/src/json-api.php
@@ -13,20 +13,24 @@ require_once 'router.php';
 class RestRouter extends Router {
 
     function route(): Controller {
-        if ($this->action === "download_email"
+        if ($this->method === "GET"
+            && $this->action === "download_email"
             && isset($this->get_vars['email_id'])
             && isset($this->get_vars['address'])) {
             return new DownloadEmailController($this->get_vars['email_id'], $this->get_vars['address'], $this->config['domains'], $this->config['blocked_usernames']);
 
-        } elseif ($this->action === "delete_email"
+        } elseif ($this->method === "DELETE"
             && isset($this->get_vars['email_id'])
             && isset($this->get_vars['address'])) {
             return new DeleteEmailController($this->get_vars['email_id'], $this->get_vars['address'], $this->config['domains'], $this->config['blocked_usernames']);
 
-        } elseif ($this->action === 'get_random_username') {
+        } elseif ($this->method === "GET"
+            && $this->action === 'random_username') {
             return new RedirectToRandomAddressController($this->config['domains']);
 
-        } elseif ($this->action === 'get_emails' && isset($this->get_vars['address'])) {
+        } elseif ($this->method === "GET"
+            && $this->action === 'emails'
+            && isset($this->get_vars['address'])) {
             return new DisplayEmailsController($this->get_vars['address'], $this->config);
 
         } else {
@@ -68,6 +72,10 @@ class JsonViewHandler implements ViewHandler {
     function downloadEmailAsRfc822($full_email, $filename) {
         $this->json(array('status' => "success", 'body' => $full_email));
     }
+
+    function invalid_input($config_domains) {
+        $this->error(400, 'Bad Request');
+    }
 }
 
 
diff --git a/src/user.php b/src/user.php
index 2f3305a..a595a38 100644
--- a/src/user.php
+++ b/src/user.php
@@ -5,6 +5,18 @@ class User {
     public $username;
     public $domain;
 
+    public static function get_random_address(array $domains): string {
+        $wordLength = rand(3, 8);
+        $container = new PronounceableWord_DependencyInjectionContainer();
+        $generator = $container->getGenerator();
+        $word = $generator->generateWordOfGivenLength($wordLength);
+        $nr = rand(51, 91);
+        $name = $word . $nr;
+
+        $domain = $domains[array_rand($domains)];
+        return "$name@$domain";
+    }
+
     public function isInvalid(array $config_domains): bool {
         if (empty($this->username) || empty($this->domain)) {
             return true;
diff --git a/src/view.php b/src/view.php
index 79be76a..f1c8b2f 100644
--- a/src/view.php
+++ b/src/view.php
@@ -15,6 +15,8 @@ interface ViewHandler {
     function newAddress($string);
 
     function downloadEmailAsRfc822($full_email, $filename);
+
+    function invalid_input($config_domains);
 }
 
 
@@ -42,4 +44,9 @@ class ServerRenderViewHandler implements ViewHandler {
         header("Content-Disposition: attachment; filename=\"$filename\"");
         print $full_email;
     }
+
+    function invalid_input($config_domains) {
+        $address = User::get_random_address($config_domains);
+        $this->newAddress($address);
+    }
 }