diff --git a/requirements.txt b/requirements.txt
index 4badcd7..1791a64 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,5 +3,8 @@ colour-runner==0.0.4
 coverage==4.0.3
 dj-database-url==0.4.1
 django==1.8.12
+factory-boy==2.6.1
 flake8==2.5.4
 flake8-import-order==0.7
+incuna-pigeon==0.1.0
+python-dateutil==2.5.2
diff --git a/tests/factories.py b/tests/factories.py
new file mode 100644
index 0000000..b76291a
--- /dev/null
+++ b/tests/factories.py
@@ -0,0 +1,12 @@
+import factory
+
+from .models import User
+
+
+class UserFactory(factory.DjangoModelFactory):
+    name = factory.Sequence('User {}'.format)
+    username = factory.Sequence('username{}'.format)
+    email = factory.Sequence('email{}@incuna.com'.format)
+
+    class Meta:
+        model = User
diff --git a/tests/models.py b/tests/models.py
new file mode 100644
index 0000000..390824d
--- /dev/null
+++ b/tests/models.py
@@ -0,0 +1,18 @@
+from django.contrib.auth.models import AbstractUser
+from django.db import models
+
+from user_deletion.managers import UserManagerMixin
+
+
+class UserManager(UserManagerMixin, models.Manager):
+    pass
+
+
+class User(AbstractUser):
+    name = models.CharField(max_length=255)
+    notified = models.BooleanField(default=False)
+
+    objects = UserManager()
+
+    def __str__(self):
+        return self.name
diff --git a/tests/run.py b/tests/run.py
index 9f086ba..85570f5 100644
--- a/tests/run.py
+++ b/tests/run.py
@@ -16,8 +16,19 @@
             default='sqlite://{}/user_deletion.db'.format(BASEDIR),
         ),
     },
-    INSTALLED_APPS=('user_deletion',),
+    INSTALLED_APPS=(
+        'tests',
+        'user_deletion',
+
+        'django.contrib.auth',
+        'django.contrib.contenttypes',
+        'django.contrib.sites',
+    ),
     MIDDLEWARE_CLASSES=(),
+
+    AUTH_USER_MODEL='tests.User',
+    SITE_ID=1,
+    DEFAULT_FROM_EMAIL='from@example.com',
 )
 
 
diff --git a/tests/test_management_commands.py b/tests/test_management_commands.py
new file mode 100644
index 0000000..c1f38f3
--- /dev/null
+++ b/tests/test_management_commands.py
@@ -0,0 +1,43 @@
+from datetime import datetime
+from io import StringIO
+
+from dateutil.relativedelta import relativedelta
+from django.core import mail
+from django.core.management import call_command
+from django.test import TestCase
+
+from .factories import UserFactory
+
+
+class TestUserNotifyManagementCommand(TestCase):
+    def setUp(self):
+        self.stdout = StringIO()
+
+    def test_no_users(self):
+        call_command('notify_users')
+        self.assertFalse(len(mail.outbox))
+
+    def test_inactive_users(self):
+        year_ago = datetime.now() + relativedelta(months=-12)
+        UserFactory.create(last_login=year_ago)
+
+        call_command('notify_users')
+
+        self.assertEqual(len(mail.outbox), 1)
+
+    def test_email(self):
+        year_ago = datetime.now() + relativedelta(months=-12)
+        UserFactory.create(last_login=year_ago)
+        call_command('notify_users')
+
+        email = mail.outbox[0]
+        self.assertEqual(email.subject, 'Re-activate your account')
+        self.assertIn('We have noticed', email.body)
+
+    def test_active_users(self):
+        # user was notified before
+        year_ago = datetime.now() + relativedelta(months=-13)
+        UserFactory.create(last_login=year_ago, notified=True)
+
+        call_command('notify_users')
+        self.assertFalse(len(mail.outbox))
diff --git a/tests/test_managers.py b/tests/test_managers.py
new file mode 100644
index 0000000..e22db2d
--- /dev/null
+++ b/tests/test_managers.py
@@ -0,0 +1,20 @@
+from dateutil.relativedelta import relativedelta
+from django.apps import apps
+from django.test import TestCase
+from django.utils import timezone
+
+from .factories import UserFactory
+from .models import User
+
+
+user_deletion_config = apps.get_app_config('user_deletion')
+
+
+class TestUserDeletionManager(TestCase):
+    def test_users_to_notify(self):
+        last_login = timezone.now() - relativedelta(months=user_deletion_config.MONTHS)
+        user = UserFactory.create(last_login=last_login)
+
+        users = User.objects.users_to_notify()
+
+        self.assertCountEqual(users, [user])
diff --git a/user_deletion/__init__.py b/user_deletion/__init__.py
index e69de29..76e2af5 100644
--- a/user_deletion/__init__.py
+++ b/user_deletion/__init__.py
@@ -0,0 +1 @@
+default_app_config = 'user_deletion.apps.UserDeletionConfig'
diff --git a/user_deletion/apps.py b/user_deletion/apps.py
new file mode 100644
index 0000000..3be77e3
--- /dev/null
+++ b/user_deletion/apps.py
@@ -0,0 +1,7 @@
+from django.apps import AppConfig
+
+
+class UserDeletionConfig(AppConfig):
+    name = 'user_deletion'
+
+    MONTHS = 12
diff --git a/user_deletion/management/commands/__init__.py b/user_deletion/management/commands/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/user_deletion/management/commands/delete_users.py b/user_deletion/management/commands/delete_users.py
new file mode 100644
index 0000000..e69de29
diff --git a/user_deletion/management/commands/notify_users.py b/user_deletion/management/commands/notify_users.py
new file mode 100644
index 0000000..8365206
--- /dev/null
+++ b/user_deletion/management/commands/notify_users.py
@@ -0,0 +1,17 @@
+from django.conf import settings
+from django.contrib.auth import get_user_model
+from django.contrib.sites.models import Site
+from django.core.management.base import BaseCommand
+from django.utils import translation
+
+from ...notifications import DeletionNotification
+
+User = get_user_model()
+
+
+class Command(BaseCommand):
+    def handle(self, *args, **options):
+        translation.activate(settings.LANGUAGE_CODE)
+        users = User.objects.users_to_notify()
+        site = Site.objects.get_current()
+        DeletionNotification(user=None, site=site, users=users).notify()
diff --git a/user_deletion/managers.py b/user_deletion/managers.py
new file mode 100644
index 0000000..e9d3826
--- /dev/null
+++ b/user_deletion/managers.py
@@ -0,0 +1,13 @@
+from dateutil.relativedelta import relativedelta
+from django.apps import apps
+from django.utils import timezone
+
+
+user_deletion_config = apps.get_app_config('user_deletion')
+
+
+class UserManagerMixin:
+    def users_to_notify(self):
+        """Finds all users who have been inactive for `MONTHS` and not yet notified."""
+        last_login = timezone.now() - relativedelta(months=user_deletion_config.MONTHS)
+        return self.filter(last_login__lte=last_login, notified=False)
diff --git a/user_deletion/notifications.py b/user_deletion/notifications.py
new file mode 100644
index 0000000..5b018b8
--- /dev/null
+++ b/user_deletion/notifications.py
@@ -0,0 +1,25 @@
+from django.conf import settings
+from django.core.mail import send_mass_mail
+from django.template.loader import render_to_string
+from django.utils.translation import ugettext_lazy as _
+from pigeon.notification import Notification
+
+
+def send_emails(notification):
+    messages = []
+    context = {'site': notification.site}
+    for user in notification.users:
+        message = render_to_string(notification.template_name, context)
+        messages.append([
+            notification.subject,
+            message,
+            settings.DEFAULT_FROM_EMAIL,
+            [user.email],
+        ])
+    send_mass_mail(messages)
+
+
+class DeletionNotification(Notification):
+    handlers = (send_emails,)
+    template_name = 'user_deletion/email.txt'
+    subject = _('Re-activate your account')
diff --git a/user_deletion/templates/user_deletion/email.txt b/user_deletion/templates/user_deletion/email.txt
new file mode 100644
index 0000000..659a8b5
--- /dev/null
+++ b/user_deletion/templates/user_deletion/email.txt
@@ -0,0 +1,7 @@
+{% load i18n %}
+{% blocktrans %}
+We have noticed that your account has been inactive for over 12 months now.
+
+Please log in to your account in order to keep it alive, otherwise it will be
+deleted within the next four weeks.
+{% endblocktrans %}