diff --git a/app/models/channel/filter/follow_up_assignment.rb b/app/models/channel/filter/follow_up_assignment.rb
new file mode 100644
index 000000000..477e9a58e
--- /dev/null
+++ b/app/models/channel/filter/follow_up_assignment.rb
@@ -0,0 +1,18 @@
+# Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/
+
+module Channel::Filter::FollowUpAssignment
+
+  def self.run(_channel, mail, _transaction_params)
+    return if !mail[:'x-zammad-ticket-id']
+
+    ticket = Ticket.lookup(id: mail[:'x-zammad-ticket-id'])
+
+    return if ticket.blank?
+    return if ticket.state.state_type.name != 'closed'
+    return if ticket.group.follow_up_assignment
+
+    mail[:'x-zammad-ticket-followup-owner'] = User.lookup(id: 1).login
+
+    true
+  end
+end
diff --git a/db/migrate/20210823112140_issue_2455_follow_up_assignment.rb b/db/migrate/20210823112140_issue_2455_follow_up_assignment.rb
new file mode 100644
index 000000000..f99636a08
--- /dev/null
+++ b/db/migrate/20210823112140_issue_2455_follow_up_assignment.rb
@@ -0,0 +1,22 @@
+# Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/
+
+class Issue2455FollowUpAssignment < ActiveRecord::Migration[6.0]
+  def change
+    # return if it's a new setup
+    return if !Setting.exists?(name: 'system_init_done')
+
+    Group.where(follow_up_assignment: false).find_each do |group|
+      group.update(follow_up_assignment: true)
+    end
+
+    Setting.create_if_not_exists(
+      title:       'Defines postmaster filter.',
+      name:        '0009_postmaster_filter_follow_up_assignment',
+      area:        'Postmaster::PreFilter',
+      description: 'Defines postmaster filter to set the owner (based on group follow up assignment).',
+      options:     {},
+      state:       'Channel::Filter::FollowUpAssignment',
+      frontend:    false
+    )
+  end
+end
diff --git a/db/seeds/settings.rb b/db/seeds/settings.rb
index 26861690c..de8e54299 100644
--- a/db/seeds/settings.rb
+++ b/db/seeds/settings.rb
@@ -3418,6 +3418,15 @@ Setting.create_if_not_exists(
   state:       'Channel::Filter::FollowUpMerged',
   frontend:    false
 )
+Setting.create_if_not_exists(
+  title:       'Defines postmaster filter.',
+  name:        '0009_postmaster_filter_follow_up_assignment',
+  area:        'Postmaster::PreFilter',
+  description: 'Defines postmaster filter to set the owner (based on group follow up assignment).',
+  options:     {},
+  state:       'Channel::Filter::FollowUpAssignment',
+  frontend:    false
+)
 Setting.create_if_not_exists(
   title:       'Defines postmaster filter.',
   name:        '0011_postmaster_sender_based_on_reply_to',
diff --git a/spec/db/migrate/issue_2455_follow_up_assignment_spec.rb b/spec/db/migrate/issue_2455_follow_up_assignment_spec.rb
new file mode 100644
index 000000000..b96c81d8a
--- /dev/null
+++ b/spec/db/migrate/issue_2455_follow_up_assignment_spec.rb
@@ -0,0 +1,11 @@
+# Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/
+
+require 'rails_helper'
+
+RSpec.describe Issue2455FollowUpAssignment, type: :db_migration do
+  let!(:group) { create(:group, follow_up_assignment: false) }
+
+  it 'sets groups to follow_up_assignment true' do
+    expect { migrate }.to change { group.reload.follow_up_assignment }.to(true)
+  end
+end
diff --git a/spec/models/channel/email_parser_spec.rb b/spec/models/channel/email_parser_spec.rb
index 528b37c45..6b15bffdc 100644
--- a/spec/models/channel/email_parser_spec.rb
+++ b/spec/models/channel/email_parser_spec.rb
@@ -902,6 +902,28 @@ RSpec.describe Channel::EmailParser, type: :model do
           expect { described_class.new.process({}, raw_mail) }
             .to change { ticket.reload.state.name }.to('open')
         end
+
+        context 'when group has follow_up_assignment true' do
+          let(:group) { create(:group, follow_up_assignment: true) }
+          let(:agent) { create(:agent, groups: [group]) }
+          let(:ticket) { create(:ticket, state_name: 'closed', owner: agent, group: group) }
+
+          it 'does not change the owner' do
+            expect { described_class.new.process({}, raw_mail) }
+              .not_to change { ticket.reload.owner.login }
+          end
+        end
+
+        context 'when group has follow_up_assignment false' do
+          let(:group) { create(:group, follow_up_assignment: false) }
+          let(:agent) { create(:agent, groups: [group]) }
+          let(:ticket) { create(:ticket, state_name: 'closed', owner: agent, group: group) }
+
+          it 'does change the owner' do
+            expect { described_class.new.process({}, raw_mail) }
+              .to change { ticket.reload.owner.login }.to eq(User.find(1).login)
+          end
+        end
       end
     end
 
diff --git a/spec/models/channel/filter/follow_up_assignment_spec.rb b/spec/models/channel/filter/follow_up_assignment_spec.rb
new file mode 100644
index 000000000..57d2e242c
--- /dev/null
+++ b/spec/models/channel/filter/follow_up_assignment_spec.rb
@@ -0,0 +1,70 @@
+# Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/
+
+require 'rails_helper'
+
+RSpec.describe Channel::Filter::FollowUpAssignment, type: :channel_filter do
+
+  context 'with group follow_up_assignment true' do
+    let(:group) { create(:group, follow_up_assignment: true) }
+
+    context 'when ticket closed' do
+      let(:ticket) { create(:ticket, group: group, state: Ticket::State.find_by(name: 'closed')) }
+
+      it 'does not change the owner' do
+        mail = {
+          'x-zammad-ticket-id': ticket.id
+        }
+
+        filter(mail)
+
+        expect(mail[:'x-zammad-ticket-followup-owner']).to be nil
+      end
+    end
+
+    context 'when ticket open' do
+      let(:ticket) { create(:ticket, group: group, state: Ticket::State.find_by(name: 'open')) }
+
+      it 'does not change the owner' do
+        mail = {
+          'x-zammad-ticket-id': ticket.id
+        }
+
+        filter(mail)
+
+        expect(mail[:'x-zammad-ticket-followup-owner']).to be nil
+      end
+    end
+  end
+
+  context 'with group follow_up_assignment false' do
+    let(:group) { create(:group, follow_up_assignment: false) }
+
+    context 'when ticket closed' do
+      let(:ticket) { create(:ticket, group: group, state: Ticket::State.find_by(name: 'closed')) }
+
+      it 'does change the owner' do
+        mail = {
+          'x-zammad-ticket-id': ticket.id
+        }
+
+        filter(mail)
+
+        expect(mail[:'x-zammad-ticket-followup-owner']).to eq(User.lookup(id: 1).login)
+      end
+    end
+
+    context 'when ticket open' do
+      let(:ticket) { create(:ticket, group: group, state: Ticket::State.find_by(name: 'open')) }
+
+      it 'does not change the owner' do
+        mail = {
+          'x-zammad-ticket-id': ticket.id
+        }
+
+        filter(mail)
+
+        expect(mail[:'x-zammad-ticket-followup-owner']).to be nil
+      end
+    end
+  end
+end