diff --git a/app/models/ticket.rb b/app/models/ticket.rb
index 83b6723d2..e2a061518 100644
--- a/app/models/ticket.rb
+++ b/app/models/ticket.rb
@@ -1209,9 +1209,16 @@ result
   end
 
   def check_owner_active
-    return true if owner.login == '-' # return when ticket is unassigned
-    return true if owner.groups.any?(&:active?) && owner.active? # return if user in any groups assigned is active and user account is active
-    self.owner = User.find_by(login: '-') # else set the owner of the ticket to the default user as unassigned
+
+    # return when ticket is unassigned
+    return true if owner_id.blank?
+    return true if owner_id == 1
+
+    # return if owner is active, is agent and has access to group of ticket
+    return true if owner.active? && owner.permissions?('ticket.agent') && owner.group_access?(group_id, 'full')
+
+    # else set the owner of the ticket to the default user as unassigned
+    self.owner_id = 1
     true
   end
 end
diff --git a/test/unit/ticket_update_test.rb b/test/unit/ticket_owner_reset_on_follow_up_test.rb
similarity index 81%
rename from test/unit/ticket_update_test.rb
rename to test/unit/ticket_owner_reset_on_follow_up_test.rb
index 21744b74a..1c162c14d 100644
--- a/test/unit/ticket_update_test.rb
+++ b/test/unit/ticket_owner_reset_on_follow_up_test.rb
@@ -1,6 +1,6 @@
 require 'test_helper'
 
-class TicketUpdateTest < ActiveSupport::TestCase
+class TicketOwnerResetOnFollowUpTest < ActiveSupport::TestCase
 
   setup do
     UserInfo.current_user_id = 1
@@ -179,6 +179,46 @@ Some Text"
 To: customer@example.com
 Subject: #{ticket.subject_build('some new subject')}
 
+Some Text"
+
+    ticket_p, article_p, user_p = Channel::EmailParser.new.process({}, email_raw)
+    assert_equal(ticket.id, ticket_p.id)
+
+    assert_equal('open', ticket_p.state.name)
+    assert_equal('-', ticket_p.owner.login)
+  end
+
+  test 'check if ticket is unassigned on follow up via email if current owner is customer now' do
+
+    ticket = Ticket.create!(
+      title: 'follow up check for invalid owner is customer now',
+      group: Group.lookup(name: 'Users'),
+      customer: @customer1,
+      owner: @agent1,
+      state: Ticket::State.lookup(name: 'closed'),
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+    article = Ticket::Article.create!(
+      ticket_id: ticket.id,
+      from: 'some_sender@example.com',
+      to: 'some_recipient@example.com',
+      subject: 'follow up check',
+      body: 'some message article',
+      internal: false,
+      sender: Ticket::Article::Sender.lookup(name: 'Agent'),
+      type: Ticket::Article::Type.lookup(name: 'email'),
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+
+    @agent1.roles = Role.where(name: 'Customer')
+    @agent1.save!
+
+    email_raw = "From: me@example.com
+To: customer@example.com
+Subject: #{ticket.subject_build('some new subject')}
+
 Some Text"
 
     ticket_p, article_p, user_p = Channel::EmailParser.new.process({}, email_raw)