diff --git a/input/management/commands/sendmails.py b/input/management/commands/sendmails.py
index 14a732a..15cac47 100755
--- a/input/management/commands/sendmails.py
+++ b/input/management/commands/sendmails.py
@@ -1,5 +1,6 @@
 from datetime import date, timedelta
 
+from django.core.management import CommandError
 from django.core.management.base import BaseCommand
 from django.template.loader import get_template
 from django.core.mail import BadHeaderError
@@ -50,8 +51,8 @@ class Command(BaseCommand):
             #      [email],
             #      bcc=[SURVEY_EMAIL])
             #survey_mail.send(fail_silently=False)
-        except BadHeaderError:
-            return HttpResponse('Invalid header found.')  # FIXME HttpResponse???
+        except BadHeaderError as error:
+            raise CommandError(f'Invalid header found: {error}')
 
         print(f'send surveylinkemail to {email}...')
 
diff --git a/input/templates/input/index.html b/input/templates/input/index.html
index 308d04c..234da25 100755
--- a/input/templates/input/index.html
+++ b/input/templates/input/index.html
@@ -29,8 +29,8 @@
     <br>Für alle Fragen wende dich gern an das <a
         href="https://de.wikipedia.org/wiki/Wikipedia:Förderung/Wikimedia_Deutschland">Team Communitys und
     Engagement</a>.
-    <br>Für interessierte Hacker gibts auch den <a
-        href="https://srcsrv.wikimedia.de/beba/foerderbarometer">Sourcecode</a> zum Formular und was damit passiert.
+    <br>Für interessierte Hacker gibts auch den
+    <a href="https://srcsrv.wikimedia.de/beba/foerderbarometer">Sourcecode</a> zum Formular und was damit passiert.
     <p>
         <a href="https://www.wikimedia.de/impressum/">Impressum</a>
     </p>
diff --git a/input/tests/views.py b/input/tests/views.py
index 4cbd3a5..f32eeea 100644
--- a/input/tests/views.py
+++ b/input/tests/views.py
@@ -1,7 +1,9 @@
+from django.shortcuts import resolve_url
 from django.test import TestCase
 
 from input.models import Library
 from input.utils.testing import create_superuser, login, request
+from input.views import TYPES
 
 
 class AnonymousViewTestCase(TestCase):
@@ -14,33 +16,36 @@ class AnonymousViewTestCase(TestCase):
     def test_extern(self):
         request(self, 'extern')
 
-    @staticmethod
-    def get_step_data(step, data):
-        return {'extern_view-current_step': step, **data}
-
     @classmethod
-    def get_first_step_data(cls, choice):
-        return cls.get_step_data(0, {
-            '0-realname': 'Test',
-            '0-email': 'test@example.com',
-            '0-choice': choice,
-            '0-check': True,
-        })
+    def get_step_data(cls, choice, **data):
+        return {
+            'realname': 'Test',
+            'email': 'test@example.com',
+            'choice': choice,
+            'check': True,
+            **data,
+        }
+
+    @staticmethod
+    def helper_url(code):
+        info = next(info for info in TYPES if info.code == code)
+
+        return resolve_url('extern', type=info.path)
 
     def helper_extern(self, choice, text, data):
-        first_step_data = self.get_first_step_data(choice)
+        url = self.helper_url(choice)
 
-        response = request(self, 'extern', data=first_step_data)
+        response = request(self, url)
 
         self.assertContains(response, text)
 
-        second_step_data = self.get_step_data(1, data)
+        data = self.get_step_data(choice, **data)
 
-        response = request(self, 'extern', data=second_step_data)
+        response = request(self, url, data=data)
 
         self.assertContains(response, 'Deine Anfrage wurde gesendet.')
 
-    def test_extern_first_steps(self):
+    def test_extern_steps(self):
         types = [
             ('BIB', 'Bibliotheksausweis'),
             ('ELIT', 'Online-Ressource'),
@@ -53,12 +58,10 @@ class AnonymousViewTestCase(TestCase):
             ('VIS', 'DIN 5008'),
         ]
 
-        for choice, text in types:
-            with self.subTest(type=choice):
-                self.client.session.clear()
-
-                data = self.get_first_step_data(choice)
-                response = request(self, 'extern', data=data)
+        for code, text in types:
+            with self.subTest(type=code):
+                url = self.helper_url(code)
+                response = request(self, url)
 
                 self.assertContains(response, text)
 
@@ -93,6 +96,10 @@ class AnonymousViewTestCase(TestCase):
             'notes': '',
         })
 
+    def test_extern_invalid_code(self):
+        request(self, 'extern', args=['invalid'], status_code=404)
+
+
 
 class AuthenticatedViewTestCase(TestCase):
 
@@ -159,4 +166,4 @@ class TermsConsentViewTests(AnonymousViewTestCase):
 
         # Expect to remain on step 2 with required field error
         self.assertNotContains(resp, 'Deine Anfrage wurde gesendet.')
-        self.assertContains(resp, 'Dieses Feld ist zwingend erforderlich.')
\ No newline at end of file
+        self.assertContains(resp, 'Dieses Feld ist zwingend erforderlich.')
diff --git a/input/views.py b/input/views.py
index f76cdb6..0a8750b 100755
--- a/input/views.py
+++ b/input/views.py
@@ -73,10 +73,6 @@ class ApplicationType(NamedTuple):
     def label(self):
         return TYPE_CHOICES[self.code]
 
-    @property
-    def model(self):
-        return MODELS[self.code]
-
     @property
     def help_texts(self):
         return HELP_TEXTS.get(self.code)