diff --git a/README.md b/README.md
index e2f8578ce..030acd785 100644
--- a/README.md
+++ b/README.md
@@ -3,9 +3,9 @@
 Zammad is a web based open source helpdesk/customer support system with many
 features to manage customer communication via several channels like telephone,
 facebook, twitter, chat and e-mails. It is distributed under the GNU AFFERO
-General Public License (AGPL) and tested on Linux, Solaris, AIX, FreeBSD,
-OpenBSD and Mac OS 10.x. Do you receive many e-mails and want to answer them
-with a team of agents?
+General Public License (AGPL).
+
+Do you receive many e-mails and want to answer them with a team of agents?
 
 You're going to love Zammad!
 
diff --git a/app/assets/javascripts/app/controllers/ticket_zoom.coffee b/app/assets/javascripts/app/controllers/ticket_zoom.coffee
index d05db0448..430a8b7d0 100644
--- a/app/assets/javascripts/app/controllers/ticket_zoom.coffee
+++ b/app/assets/javascripts/app/controllers/ticket_zoom.coffee
@@ -848,7 +848,7 @@ class App.TicketZoom extends App.Controller
       error: (settings, details) =>
         App.Event.trigger 'notify', {
           type:    'error'
-          msg:     App.i18n.translateContent(details.error_human || details.error || 'Unable to update!')
+          msg:     App.i18n.translateContent(details.error_human || details.error || settings.responseJSON.error || 'Unable to update!')
           timeout: 2000
         }
         @autosaveStart()
diff --git a/app/assets/javascripts/app/controllers/ticket_zoom/sidebar_ticket.coffee b/app/assets/javascripts/app/controllers/ticket_zoom/sidebar_ticket.coffee
index 53253d729..76bfeff9e 100644
--- a/app/assets/javascripts/app/controllers/ticket_zoom/sidebar_ticket.coffee
+++ b/app/assets/javascripts/app/controllers/ticket_zoom/sidebar_ticket.coffee
@@ -8,23 +8,42 @@ class Edit extends App.ObserverController
   render: (ticket, diff) =>
     defaults = ticket.attributes()
     delete defaults.article # ignore article infos
+    followUpPossible = App.Group.find(defaults.group_id).follow_up_possible
+    ticketState = App.TicketState.find(defaults.state_id).name
+
     taskState = @taskGet('ticket')
 
     if !_.isEmpty(taskState)
       defaults = _.extend(defaults, taskState)
 
-    new App.ControllerForm(
-      elReplace: @el
-      model:     App.Ticket
-      screen:    'edit'
-      handlers:  [
-        @ticketFormChanges
-      ]
-      filter:     @formMeta.filter
-      params:     defaults
-      isDisabled: !ticket.editable()
-      #bookmarkable: true
-    )
+    if followUpPossible == 'new_ticket' && ticketState != 'closed' ||
+       followUpPossible != 'new_ticket' ||
+       @permissionCheck('admin') || @permissionCheck('ticket.agent')
+      new App.ControllerForm(
+        elReplace: @el
+        model:     App.Ticket
+        screen:    'edit'
+        handlers:  [
+          @ticketFormChanges
+        ]
+        filter:     @formMeta.filter
+        params:     defaults
+        isDisabled: !ticket.editable()
+        #bookmarkable: true
+      )
+    else
+      new App.ControllerForm(
+        elReplace: @el
+        model:     App.Ticket
+        screen:    'edit'
+        handlers:  [
+          @ticketFormChanges
+        ]
+        filter:     @formMeta.filter
+        params:     defaults
+        isDisabled: ticket.editable()
+        #bookmarkable: true
+      )
 
     @markForm(true)
 
diff --git a/app/assets/javascripts/app/lib/app_post/utils.coffee b/app/assets/javascripts/app/lib/app_post/utils.coffee
index 0bc5a7f97..134deb96e 100644
--- a/app/assets/javascripts/app/lib/app_post/utils.coffee
+++ b/app/assets/javascripts/app/lib/app_post/utils.coffee
@@ -964,8 +964,8 @@ class App.Utils
         senders = App.Utils.parseAddressListLocal(article.from)
         if senders
           for sender in senders
-            if sender && sender.address && sender.address.match('@')
-              senderIsLocal = isLocalAddress(sender.address)
+            if sender && sender.match('@')
+              senderIsLocal = isLocalAddress(sender)
 
       # check if article recipient is local
       recipientIsLocal = false
diff --git a/app/controllers/tickets_controller.rb b/app/controllers/tickets_controller.rb
index 9b2414be3..dbdf36ef6 100644
--- a/app/controllers/tickets_controller.rb
+++ b/app/controllers/tickets_controller.rb
@@ -7,6 +7,7 @@ class TicketsController < ApplicationController
   include TicketStats
 
   prepend_before_action :authentication_check
+  before_action :follow_up_possible_check, only: :update
 
   # GET /api/v1/tickets
   def index
@@ -124,7 +125,7 @@ class TicketsController < ApplicationController
       if !local_customer && clean_customer[:id].present?
         local_customer = User.find_by(id: clean_customer[:id])
       end
-      if clean_customer[:email].present?
+      if !local_customer && clean_customer[:email].present?
         local_customer = User.find_by(email: clean_customer[:email].downcase)
       end
       if !local_customer && clean_customer[:login].present?
@@ -599,6 +600,14 @@ class TicketsController < ApplicationController
 
   private
 
+  def follow_up_possible_check
+    ticket = Ticket.find(params[:id])
+
+    return true if ticket.group.follow_up_possible != 'new_ticket' # check if the setting for follow_up_possible is disabled
+    return true if ticket.state.name != 'closed' # check if the ticket state is already closed
+    raise Exceptions::UnprocessableEntity, 'Cannot follow up on a closed ticket. Please create a new ticket.'
+  end
+
   def ticket_all(ticket)
 
     # get attributes to update
diff --git a/test/controllers/tickets_controller_test.rb b/test/controllers/tickets_controller_test.rb
index 785ab7001..bc86dfc57 100644
--- a/test/controllers/tickets_controller_test.rb
+++ b/test/controllers/tickets_controller_test.rb
@@ -48,6 +48,7 @@ class TicketsControllerTest < ActionDispatch::IntegrationTest
       roles: roles,
     )
     UserInfo.current_user_id = nil
+
   end
 
   test '01.01 ticket create with agent - missing group' do
@@ -1733,4 +1734,76 @@ AAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO
 
   end
 
+  test '06.01 - ticket with follow up possible set to new_ticket' do
+    group = Group.create_or_update(
+      name: "GroupWithNoFollowUp-#{rand(9_999_999_999)}",
+      active: true,
+      updated_by_id: 1,
+      created_by_id: 1,
+      follow_up_possible: 'new_ticket' # disable follow up possible
+    )
+
+    ticket = Ticket.create!(
+      title: 'ticket with wrong ticket id',
+      group_id: group.id,
+      customer_id: @customer_without_org.id,
+      state: Ticket::State.lookup(name: 'closed'), # set the ticket to closed
+      priority: Ticket::Priority.lookup(name: '2 normal'),
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+
+    state = Ticket::State.find_by(name: 'open') # try to open a ticket from a closed state
+
+    # customer
+    credentials = ActionController::HttpAuthentication::Basic.encode_credentials('tickets-customer1@example.com', 'customer1pw')
+    params = {
+      state_id: state.id, # set the state id
+    }
+
+    put "/api/v1/tickets/#{ticket.id}", params: params.to_json, headers: @headers.merge('Authorization' => credentials)
+    assert_response(422)
+    result = JSON.parse(@response.body)
+    assert_equal(Hash, result.class)
+    assert_equal('Cannot follow up on a closed ticket. Please create a new ticket.', result['error'])
+
+    ticket = Ticket.create!(
+      title: 'ticket with wrong ticket id',
+      group_id: group.id,
+      customer_id: @customer_without_org.id,
+      state: Ticket::State.lookup(name: 'closed'), # set the ticket to closed
+      priority: Ticket::Priority.lookup(name: '2 normal'),
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+
+    # admin
+    credentials = ActionController::HttpAuthentication::Basic.encode_credentials('tickets-admin@example.com', 'adminpw')
+
+    put "/api/v1/tickets/#{ticket.id}", params: params.to_json, headers: @headers.merge('Authorization' => credentials)
+    assert_response(422)
+    result = JSON.parse(@response.body)
+    assert_equal(Hash, result.class)
+    assert_equal('Cannot follow up on a closed ticket. Please create a new ticket.', result['error'])
+
+    ticket = Ticket.create!(
+      title: 'ticket with wrong ticket id',
+      group_id: group.id,
+      customer_id: @customer_without_org.id,
+      state: Ticket::State.lookup(name: 'closed'), # set the ticket to closed
+      priority: Ticket::Priority.lookup(name: '2 normal'),
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+
+    # agent
+    credentials = ActionController::HttpAuthentication::Basic.encode_credentials('tickets-agent@example.com', 'agentpw')
+
+    put "/api/v1/tickets/#{ticket.id}", params: params.to_json, headers: @headers.merge('Authorization' => credentials)
+    assert_response(422)
+    result = JSON.parse(@response.body)
+    assert_equal(Hash, result.class)
+    assert_equal('Cannot follow up on a closed ticket. Please create a new ticket.', result['error'])
+  end
+
 end