diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 4ae3f02..a45b8a7 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -83,4 +83,4 @@ python linting:
   script:
     - isort -rc src/ --check-only
     - black -l 88 --check src/
-    - autoflake -rc src/
+    - autoflake --check --remove-all-unused-imports --ignore-init-module-imports --recursive src/
diff --git a/src/newsreader/accounts/tests/test_activation.py b/src/newsreader/accounts/tests/test_activation.py
index b5a9943..45d0909 100644
--- a/src/newsreader/accounts/tests/test_activation.py
+++ b/src/newsreader/accounts/tests/test_activation.py
@@ -1,16 +1,13 @@
 import datetime
 
 from django.conf import settings
-from django.core import mail
 from django.test import TestCase
-from django.test.utils import override_settings
 from django.urls import reverse
 from django.utils.translation import gettext as _
 
 from registration.models import RegistrationProfile
 
 from newsreader.accounts.models import User
-from newsreader.accounts.tests.factories import UserFactory
 
 
 class ActivationTestCase(TestCase):
diff --git a/src/newsreader/accounts/tests/test_password_reset.py b/src/newsreader/accounts/tests/test_password_reset.py
index 1f818c8..c7871d5 100644
--- a/src/newsreader/accounts/tests/test_password_reset.py
+++ b/src/newsreader/accounts/tests/test_password_reset.py
@@ -1,14 +1,10 @@
 from typing import Dict
 
-from django.contrib.auth.tokens import default_token_generator as token_generator
 from django.core import mail
 from django.test import TestCase
 from django.urls import reverse
-from django.utils.encoding import force_bytes
-from django.utils.http import urlsafe_base64_encode
 from django.utils.translation import gettext as _
 
-from newsreader.accounts.models import User
 from newsreader.accounts.tests.factories import UserFactory
 
 
diff --git a/src/newsreader/accounts/tests/test_resend_activation.py b/src/newsreader/accounts/tests/test_resend_activation.py
index a18df2a..0209f94 100644
--- a/src/newsreader/accounts/tests/test_resend_activation.py
+++ b/src/newsreader/accounts/tests/test_resend_activation.py
@@ -1,13 +1,10 @@
-from django.conf import settings
 from django.core import mail
 from django.test import TransactionTestCase as TestCase
-from django.test.utils import override_settings
 from django.urls import reverse
 from django.utils.translation import gettext as _
 
 from registration.models import RegistrationProfile
 
-from newsreader.accounts.models import User
 from newsreader.accounts.tests.factories import RegistrationProfileFactory, UserFactory
 
 
diff --git a/src/newsreader/accounts/tests/tests.py b/src/newsreader/accounts/tests/tests.py
index b87e8fd..e28dbd3 100644
--- a/src/newsreader/accounts/tests/tests.py
+++ b/src/newsreader/accounts/tests/tests.py
@@ -1,6 +1,6 @@
 from django.test import TestCase
 
-from django_celery_beat.models import IntervalSchedule, PeriodicTask
+from django_celery_beat.models import PeriodicTask
 
 from newsreader.accounts.models import User
 
diff --git a/src/newsreader/accounts/urls.py b/src/newsreader/accounts/urls.py
index 7b869c7..8605233 100644
--- a/src/newsreader/accounts/urls.py
+++ b/src/newsreader/accounts/urls.py
@@ -1,4 +1,4 @@
-from django.urls import include, path
+from django.urls import path
 
 from newsreader.accounts.views import (
     ActivationCompleteView,
diff --git a/src/newsreader/conf/dev.py b/src/newsreader/conf/dev.py
index 9d77952..16cf03b 100644
--- a/src/newsreader/conf/dev.py
+++ b/src/newsreader/conf/dev.py
@@ -1,4 +1,4 @@
-from .base import *
+from .base import *  # isort:skip
 
 
 DEBUG = True
diff --git a/src/newsreader/conf/docker.py b/src/newsreader/conf/docker.py
index fe20d06..5643937 100644
--- a/src/newsreader/conf/docker.py
+++ b/src/newsreader/conf/docker.py
@@ -1,5 +1,4 @@
-from .dev import *
-
+from .dev import *  # isort:skip
 
 # Celery
 # https://docs.celeryproject.org/en/latest/userguide/configuration.html
diff --git a/src/newsreader/conf/gitlab.py b/src/newsreader/conf/gitlab.py
index 3108245..ee11c59 100644
--- a/src/newsreader/conf/gitlab.py
+++ b/src/newsreader/conf/gitlab.py
@@ -1,4 +1,4 @@
-from .base import *  # noqa
+from .base import *  # isort:skip
 
 
 DEBUG = True
diff --git a/src/newsreader/news/collection/base.py b/src/newsreader/news/collection/base.py
index ea8e015..519f4f8 100644
--- a/src/newsreader/news/collection/base.py
+++ b/src/newsreader/news/collection/base.py
@@ -1,5 +1,3 @@
-from django.db.models.query import QuerySet
-
 from bs4 import BeautifulSoup
 
 from newsreader.news.collection.exceptions import StreamParseException
diff --git a/src/newsreader/news/collection/endpoints.py b/src/newsreader/news/collection/endpoints.py
index 0a13766..7f2ede0 100644
--- a/src/newsreader/news/collection/endpoints.py
+++ b/src/newsreader/news/collection/endpoints.py
@@ -6,7 +6,6 @@ from rest_framework.generics import (
     get_object_or_404,
 )
 from rest_framework.response import Response
-from rest_framework.serializers import Serializer
 
 from newsreader.core.pagination import LargeResultSetPagination, ResultSetPagination
 from newsreader.news.collection.models import CollectionRule
diff --git a/src/newsreader/news/collection/feed.py b/src/newsreader/news/collection/feed.py
index 0e8b258..46a7a3b 100644
--- a/src/newsreader/news/collection/feed.py
+++ b/src/newsreader/news/collection/feed.py
@@ -1,5 +1,8 @@
+import logging
+
 from concurrent.futures import ThreadPoolExecutor, as_completed
 
+from django.core.exceptions import MultipleObjectsReturned, ObjectDoesNotExist
 from django.db.models.fields import CharField, TextField
 from django.template.defaultfilters import truncatechars
 from django.utils import timezone
@@ -21,11 +24,13 @@ from newsreader.news.collection.exceptions import (
     StreamParseException,
     StreamTimeOutException,
 )
-from newsreader.news.collection.models import CollectionRule
 from newsreader.news.collection.utils import build_publication_date, fetch
 from newsreader.news.core.models import Post
 
 
+logger = logging.getLogger(__name__)
+
+
 class FeedBuilder(Builder):
     instances = []
 
@@ -164,7 +169,8 @@ class FeedClient(Client):
 
                     yield response_data
                 except StreamException as e:
-                    stream.rule.error = e.message
+                    length = stream.rule._meta.get_field("error").max_length
+                    stream.rule.error = e.message[-length:]
                     stream.rule.succeeded = False
 
                     yield ({"entries": []}, stream)
@@ -195,8 +201,8 @@ class FeedDuplicateHandler:
             if instance.remote_identifier in self.existing_identifiers:
                 existing_post = self.handle_duplicate(instance)
 
-                if existing_post:
-                    yield existing_post
+                yield existing_post
+
                 continue
             elif not instance.remote_identifier and self.in_database(instance):
                 continue
@@ -229,7 +235,16 @@ class FeedDuplicateHandler:
                 remote_identifier=instance.remote_identifier
             )
         except ObjectDoesNotExist:
-            return
+            logger.error(
+                f"Duplicate handler tried retrieving post {instance.remote_identifier} but failed doing so."
+            )
+            return instance
+        except MultipleObjectsReturned:
+            existing_instances = self.queryset.filter(
+                remote_identifier=instance.remote_identifier
+            ).order_by("-publication_date")
+            existing_instance = existing_instances.last()
+            existing_instances.exclude(pk=existing_instance.pk).delete()
 
         for field in instance._meta.get_fields():
             getattr(existing_instance, field.name, object())
diff --git a/src/newsreader/news/collection/migrations/0005_auto_20200303_1932.py b/src/newsreader/news/collection/migrations/0005_auto_20200303_1932.py
new file mode 100644
index 0000000..cdd3e32
--- /dev/null
+++ b/src/newsreader/news/collection/migrations/0005_auto_20200303_1932.py
@@ -0,0 +1,16 @@
+# Generated by Django 2.2 on 2020-03-03 19:32
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [("collection", "0004_auto_20190714_1422")]
+
+    operations = [
+        migrations.AlterField(
+            model_name="collectionrule",
+            name="error",
+            field=models.CharField(blank=True, max_length=1024, null=True),
+        )
+    ]
diff --git a/src/newsreader/news/collection/models.py b/src/newsreader/news/collection/models.py
index 04ea596..8552ebf 100644
--- a/src/newsreader/news/collection/models.py
+++ b/src/newsreader/news/collection/models.py
@@ -33,7 +33,7 @@ class CollectionRule(TimeStampedModel):
 
     last_suceeded = models.DateTimeField(blank=True, null=True)
     succeeded = models.BooleanField(default=False)
-    error = models.CharField(max_length=255, blank=True, null=True)
+    error = models.CharField(max_length=1024, blank=True, null=True)
 
     user = models.ForeignKey("accounts.User", _("Owner"), related_name="rules")
 
diff --git a/src/newsreader/news/collection/tests/endpoints/rule/detail/tests.py b/src/newsreader/news/collection/tests/endpoints/rule/detail/tests.py
index a489d55..1c281d9 100644
--- a/src/newsreader/news/collection/tests/endpoints/rule/detail/tests.py
+++ b/src/newsreader/news/collection/tests/endpoints/rule/detail/tests.py
@@ -1,6 +1,6 @@
 import json
 
-from django.test import Client, TestCase
+from django.test import TestCase
 from django.urls import reverse
 
 from newsreader.accounts.tests.factories import UserFactory
diff --git a/src/newsreader/news/collection/tests/endpoints/rule/list/tests.py b/src/newsreader/news/collection/tests/endpoints/rule/list/tests.py
index 32d8a0d..0e2a269 100644
--- a/src/newsreader/news/collection/tests/endpoints/rule/list/tests.py
+++ b/src/newsreader/news/collection/tests/endpoints/rule/list/tests.py
@@ -2,7 +2,7 @@ import json
 
 from datetime import date, datetime, time
 
-from django.test import Client, TestCase
+from django.test import TestCase
 from django.urls import reverse
 
 import pytz
diff --git a/src/newsreader/news/collection/tests/feed/client/tests.py b/src/newsreader/news/collection/tests/feed/client/tests.py
index 9c11cbd..dd3c1e4 100644
--- a/src/newsreader/news/collection/tests/feed/client/tests.py
+++ b/src/newsreader/news/collection/tests/feed/client/tests.py
@@ -1,6 +1,7 @@
 from unittest.mock import MagicMock, patch
 
 from django.test import TestCase
+from django.utils.lorem_ipsum import words
 
 from newsreader.news.collection.exceptions import (
     StreamDeniedException,
@@ -101,3 +102,29 @@ class FeedClientTestCase(TestCase):
                 self.assertEquals(stream.rule.succeeded, False)
 
         self.mocked_read.assert_called_once_with()
+
+    def test_client_catches_stream_parse_exception(self):
+        rule = CollectionRuleFactory.create()
+        mock_stream = MagicMock(rule=rule)
+        self.mocked_read.side_effect = StreamParseException("Stream has wrong contents")
+
+        with FeedClient([rule]) as client:
+            for data, stream in client:
+                self.assertEquals(data, {"entries": []})
+                self.assertEquals(stream.rule.error, "Stream has wrong contents")
+                self.assertEquals(stream.rule.succeeded, False)
+
+        self.mocked_read.assert_called_once_with()
+
+    def test_client_catches_long_exception_text(self):
+        rule = CollectionRuleFactory.create()
+        mock_stream = MagicMock(rule=rule)
+        self.mocked_read.side_effect = StreamParseException(words(1000))
+
+        with FeedClient([rule]) as client:
+            for data, stream in client:
+                self.assertEquals(data, {"entries": []})
+                self.assertEquals(len(stream.rule.error), 1024)
+                self.assertEquals(stream.rule.succeeded, False)
+
+        self.mocked_read.assert_called_once_with()
diff --git a/src/newsreader/news/collection/tests/feed/duplicate_handler/tests.py b/src/newsreader/news/collection/tests/feed/duplicate_handler/tests.py
index 18b6a99..b794f3e 100644
--- a/src/newsreader/news/collection/tests/feed/duplicate_handler/tests.py
+++ b/src/newsreader/news/collection/tests/feed/duplicate_handler/tests.py
@@ -33,7 +33,7 @@ class FeedDuplicateHandlerTestCase(TestCase):
         self.assertTrue(post.title != existing_post.title)
 
     def test_duplicate_entries_in_recent_database(self):
-        PostFactory.create_batch(size=20)
+        PostFactory.create_batch(size=10)
 
         publication_date = timezone.now()
 
@@ -60,3 +60,24 @@ class FeedDuplicateHandlerTestCase(TestCase):
             posts = list(posts_gen)
 
         self.assertEquals(len(posts), 0)
+
+    def test_multiple_existing_entries_with_identifier(self):
+        timezone.now()
+        rule = CollectionRuleFactory()
+
+        PostFactory.create_batch(
+            remote_identifier="28f79ae4-8f9a-11e9-b143-00163ef6bee7", rule=rule, size=5
+        )
+
+        new_post = PostFactory.build(
+            remote_identifier="28f79ae4-8f9a-11e9-b143-00163ef6bee7",
+            title="This is a new one",
+            rule=rule,
+        )
+
+        with FeedDuplicateHandler(rule) as duplicate_handler:
+            posts_gen = duplicate_handler.check([new_post])
+            posts = list(posts_gen)
+
+        self.assertEquals(len(posts), 1)
+        self.assertEquals(posts[0].title, new_post.title)
diff --git a/src/newsreader/news/collection/tests/test_views.py b/src/newsreader/news/collection/tests/test_views.py
index 7515b98..a9b07d0 100644
--- a/src/newsreader/news/collection/tests/test_views.py
+++ b/src/newsreader/news/collection/tests/test_views.py
@@ -1,7 +1,7 @@
 import os
 
 from django.conf import settings
-from django.test import Client, TestCase
+from django.test import TestCase
 from django.urls import reverse
 from django.utils.translation import gettext_lazy as _
 
diff --git a/src/newsreader/news/collection/utils.py b/src/newsreader/news/collection/utils.py
index 261dc14..0aa096f 100644
--- a/src/newsreader/news/collection/utils.py
+++ b/src/newsreader/news/collection/utils.py
@@ -5,7 +5,6 @@ from django.utils import timezone
 import requests
 
 from requests.exceptions import RequestException
-from requests.models import Response
 
 from newsreader.news.collection.response_handler import ResponseHandler
 
diff --git a/src/newsreader/news/core/endpoints.py b/src/newsreader/news/core/endpoints.py
index 91736a9..acc4ab2 100644
--- a/src/newsreader/news/core/endpoints.py
+++ b/src/newsreader/news/core/endpoints.py
@@ -13,8 +13,7 @@ from rest_framework.permissions import IsAuthenticated
 from rest_framework.response import Response
 
 from newsreader.accounts.permissions import IsPostOwner
-from newsreader.core.pagination import LargeResultSetPagination, ResultSetPagination
-from newsreader.news.collection.models import CollectionRule
+from newsreader.core.pagination import LargeResultSetPagination
 from newsreader.news.collection.serializers import RuleSerializer
 from newsreader.news.core.filters import ReadFilter
 from newsreader.news.core.models import Category, Post
diff --git a/src/newsreader/news/core/serializers.py b/src/newsreader/news/core/serializers.py
index e6c7a08..d4353c9 100644
--- a/src/newsreader/news/core/serializers.py
+++ b/src/newsreader/news/core/serializers.py
@@ -1,6 +1,5 @@
 from rest_framework import serializers
 
-from newsreader.news import collection
 from newsreader.news.core.models import Category, Post
 
 
diff --git a/src/newsreader/news/core/tests/endpoints/category/detail/tests.py b/src/newsreader/news/core/tests/endpoints/category/detail/tests.py
index 05b4e92..2bd6bcb 100644
--- a/src/newsreader/news/core/tests/endpoints/category/detail/tests.py
+++ b/src/newsreader/news/core/tests/endpoints/category/detail/tests.py
@@ -1,6 +1,6 @@
 import json
 
-from django.test import Client, TestCase
+from django.test import TestCase
 from django.urls import reverse
 
 from newsreader.accounts.tests.factories import UserFactory
diff --git a/src/newsreader/news/core/tests/endpoints/category/list/tests.py b/src/newsreader/news/core/tests/endpoints/category/list/tests.py
index 043e805..d44f204 100644
--- a/src/newsreader/news/core/tests/endpoints/category/list/tests.py
+++ b/src/newsreader/news/core/tests/endpoints/category/list/tests.py
@@ -2,7 +2,7 @@ import json
 
 from datetime import date, datetime, time
 
-from django.test import Client, TestCase
+from django.test import TestCase
 from django.urls import reverse
 
 import pytz
diff --git a/src/newsreader/news/core/tests/endpoints/post/detail/tests.py b/src/newsreader/news/core/tests/endpoints/post/detail/tests.py
index f012cc2..7c8c31e 100644
--- a/src/newsreader/news/core/tests/endpoints/post/detail/tests.py
+++ b/src/newsreader/news/core/tests/endpoints/post/detail/tests.py
@@ -1,6 +1,6 @@
 import json
 
-from django.test import Client, TestCase
+from django.test import TestCase
 from django.urls import reverse
 
 from newsreader.accounts.tests.factories import UserFactory
diff --git a/src/newsreader/news/core/tests/endpoints/post/list/tests.py b/src/newsreader/news/core/tests/endpoints/post/list/tests.py
index ba7aba9..f3639bf 100644
--- a/src/newsreader/news/core/tests/endpoints/post/list/tests.py
+++ b/src/newsreader/news/core/tests/endpoints/post/list/tests.py
@@ -1,6 +1,6 @@
 from datetime import date, datetime, time
 
-from django.test import Client, TestCase
+from django.test import TestCase
 from django.urls import reverse
 
 import pytz
diff --git a/src/newsreader/news/core/tests/test_views.py b/src/newsreader/news/core/tests/test_views.py
index 12861fb..e4bf458 100644
--- a/src/newsreader/news/core/tests/test_views.py
+++ b/src/newsreader/news/core/tests/test_views.py
@@ -1,4 +1,4 @@
-from django.test import Client, TestCase
+from django.test import TestCase
 from django.urls import reverse
 
 from newsreader.accounts.tests.factories import UserFactory