diff --git a/taiga/projects/mixins/notifications.py b/taiga/projects/mixins/notifications.py
deleted file mode 100644
index 7b34038f..00000000
--- a/taiga/projects/mixins/notifications.py
+++ /dev/null
@@ -1,109 +0,0 @@
-# Copyright (C) 2014 Andrey Antukh <niwi@niwi.be>
-# Copyright (C) 2014 Jesús Espino <jespinog@gmail.com>
-# Copyright (C) 2014 David Barragán <bameda@dbarragan.com>
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Affero General Public License as
-# published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Affero General Public License for more details.
-#
-# You should have received a copy of the GNU Affero General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-
-#######
-# API #
-#######
-
-from taiga.projects.notifications import services
-from taiga.projects.history.services import take_snapshot
-from taiga.projects.history.models import HistoryType
-
-
-class NotificationSenderMixin(object):
-    create_notification_template = None
-    update_notification_template = None
-    destroy_notification_template = None
-    notification_service = services.NotificationService()
-
-    def _get_object_for_snapshot(self, obj):
-        return obj
-
-    def _post_save_notification_sender(self, obj, history):
-        users = obj.get_watchers_to_notify(history.owner)
-        context = {
-            "object": obj,
-            "changer": history.owner,
-            "comment": history.comment,
-            "changed_fields": history.values_diff
-        }
-
-        if history.type == HistoryType.create:
-            self.notification_service.send_notification_email(self.create_notification_template,
-                                                              users=users, context=context)
-        else:
-            self.notification_service.send_notification_email(self.update_notification_template,
-                                                              users=users, context=context)
-
-    def post_save(self, obj, created=False):
-        super().post_save(obj, created)
-
-        user = self.request.user
-        comment = self.request.DATA.get("comment", "")
-
-        obj = self._get_object_for_snapshot(obj)
-        history = take_snapshot(obj, comment=comment, user=user)
-
-        if history:
-            self._post_save_notification_sender(obj, history)
-
-    def pre_destroy(self, obj):
-        obj = self._get_object_for_snapshot(obj)
-        users = obj.get_watchers_to_notify(self.request.user)
-
-        context = {
-            "object": obj,
-            "changer": self.request.user
-        }
-        self.notification_service.send_notification_email(self.destroy_notification_template,
-                                                          users=users, context=context)
-    def post_destroy(self, obj):
-        pass
-
-    def destroy(self, request, *args, **kwargs):
-        obj = self.get_object()
-
-        self.pre_destroy(obj)
-        result = super().destroy(request, *args, **kwargs)
-        self.post_destroy(obj)
-
-        return result
-
-
-################
-# SERIEALIZERS #
-################
-
-from django.db.models.loading import get_model
-
-from rest_framework import serializers
-
-
-class WatcherValidationSerializerMixin(object):
-    def validate_watchers(self, attrs, source):
-        values =  set(attrs.get(source, []))
-        if values:
-            project = None
-            if "project" in attrs and attrs["project"]:
-                project = attrs["project"]
-            elif self.object:
-                project = self.object.project
-
-            model_cls = get_model("projects", "Membership")
-            if len(values) != model_cls.objects.filter(project=project, user__in=values).count():
-                raise serializers.ValidationError("Error, some watcher user is not a member of the project")
-        return attrs