diff --git a/app/models/observer/ticket/article_changes.rb b/app/models/observer/ticket/article_changes.rb
index a4512a759..922dcb2ab 100644
--- a/app/models/observer/ticket/article_changes.rb
+++ b/app/models/observer/ticket/article_changes.rb
@@ -70,12 +70,18 @@ class Observer::Ticket::ArticleChanges < ActiveRecord::Observer
 
     # if sender is customer
     sender = Ticket::Article::Sender.lookup(id: record.sender_id)
+    ticket = record.ticket
     if sender.name == 'Customer'
 
+      # if customer is sending agains, ignore update of last contact (usecase of update escalation)
+      return true if ticket.last_contact_customer &&
+                     ticket.last_contact &&
+                     ticket.last_contact_customer == ticket.last_contact
+
       # check if last communication is done by agent, else do not set last_contact_customer
-      if record.ticket.last_contact_customer.nil? ||
-         record.ticket.last_contact_agent.nil? ||
-         record.ticket.last_contact_agent.to_i > record.ticket.last_contact_customer.to_i
+      if ticket.last_contact_customer.nil? ||
+         ticket.last_contact_agent.nil? ||
+         ticket.last_contact_agent.to_i > ticket.last_contact_customer.to_i
 
         # set last_contact customer
         record.ticket.last_contact_customer = record.created_at
diff --git a/test/unit/ticket_test.rb b/test/unit/ticket_test.rb
index 926fe111f..d8300c9ae 100644
--- a/test/unit/ticket_test.rb
+++ b/test/unit/ticket_test.rb
@@ -18,26 +18,51 @@ class TicketTest < ActiveSupport::TestCase
     assert_equal( ticket.group.name, 'Users', 'ticket.group verify' )
     assert_equal( ticket.state.name, 'new', 'ticket.state verify' )
 
-    # create inbound article
-    article_inbound = Ticket::Article.create(
+    # create inbound article #1
+    article_inbound1 = Ticket::Article.create(
       ticket_id: ticket.id,
       from: 'some_sender@example.com',
       to: 'some_recipient@example.com',
       subject: 'some subject',
       message_id: 'some@id',
-      body: 'some message article_inbound 😍😍😍',
+      body: 'some message article_inbound1 😍😍😍',
       internal: false,
       sender: Ticket::Article::Sender.where(name: 'Customer').first,
       type: Ticket::Article::Type.where(name: 'email').first,
       updated_by_id: 1,
       created_by_id: 1,
     )
-    assert_equal( article_inbound.body, 'some message article_inbound 😍😍😍'.utf8_to_3bytesutf8, 'article_inbound.body verify - inbound' )
+    assert_equal( article_inbound1.body, 'some message article_inbound1 😍😍😍'.utf8_to_3bytesutf8, 'article_inbound.body verify - inbound' )
 
     ticket = Ticket.find(ticket.id)
     assert_equal( ticket.article_count, 1, 'ticket.article_count verify - inbound' )
-    assert_equal( ticket.last_contact.to_s, article_inbound.created_at.to_s, 'ticket.last_contact verify - inbound' )
-    assert_equal( ticket.last_contact_customer.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer verify - inbound' )
+    assert_equal( ticket.last_contact.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact verify - inbound' )
+    assert_equal( ticket.last_contact_customer.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact_customer verify - inbound' )
+    assert_equal( ticket.last_contact_agent, nil, 'ticket.last_contact_agent verify - inbound' )
+    assert_equal( ticket.first_response, nil, 'ticket.first_response verify - inbound' )
+    assert_equal( ticket.close_time, nil, 'ticket.close_time verify - inbound' )
+
+    # create inbound article #2
+    sleep 2
+    article_inbound2 = Ticket::Article.create(
+      ticket_id: ticket.id,
+      from: 'some_sender@example.com',
+      to: 'some_recipient@example.com',
+      subject: 'some subject',
+      message_id: 'some@id',
+      body: 'some message article_inbound2 😍😍😍',
+      internal: false,
+      sender: Ticket::Article::Sender.where(name: 'Customer').first,
+      type: Ticket::Article::Type.where(name: 'email').first,
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+    assert_equal( article_inbound2.body, 'some message article_inbound2 😍😍😍'.utf8_to_3bytesutf8, 'article_inbound.body verify - inbound' )
+
+    ticket = Ticket.find(ticket.id)
+    assert_equal( ticket.article_count, 2, 'ticket.article_count verify - inbound' )
+    assert_equal( ticket.last_contact.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact verify - inbound' )
+    assert_equal( ticket.last_contact_customer.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact_customer verify - inbound' )
     assert_equal( ticket.last_contact_agent, nil, 'ticket.last_contact_agent verify - inbound' )
     assert_equal( ticket.first_response, nil, 'ticket.first_response verify - inbound' )
     assert_equal( ticket.close_time, nil, 'ticket.close_time verify - inbound' )
@@ -58,15 +83,15 @@ class TicketTest < ActiveSupport::TestCase
     assert_equal( article_note.body, "some\n message", 'article_note.body verify - inbound' )
 
     ticket = Ticket.find(ticket.id)
-    assert_equal( ticket.article_count, 2, 'ticket.article_count verify - note' )
-    assert_equal( ticket.last_contact.to_s, article_inbound.created_at.to_s, 'ticket.last_contact verify - note' )
-    assert_equal( ticket.last_contact_customer.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer verify - note' )
+    assert_equal( ticket.article_count, 3, 'ticket.article_count verify - note' )
+    assert_equal( ticket.last_contact.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact verify - note' )
+    assert_equal( ticket.last_contact_customer.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact_customer verify - note' )
     assert_equal( ticket.last_contact_agent, nil, 'ticket.last_contact_agent verify - note' )
     assert_equal( ticket.first_response, nil, 'ticket.first_response verify - note' )
     assert_equal( ticket.close_time, nil, 'ticket.close_time verify - note' )
 
     # create outbound article
-    sleep 10
+    sleep 2
     article_outbound = Ticket::Article.create(
       ticket_id: ticket.id,
       from: 'some_recipient@example.com',
@@ -82,9 +107,58 @@ class TicketTest < ActiveSupport::TestCase
     )
 
     ticket = Ticket.find(ticket.id)
-    assert_equal( ticket.article_count, 3, 'ticket.article_count verify - outbound' )
+    assert_equal( ticket.article_count, 4, 'ticket.article_count verify - outbound' )
     assert_equal( ticket.last_contact.to_s, article_outbound.created_at.to_s, 'ticket.last_contact verify - outbound' )
-    assert_equal( ticket.last_contact_customer.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer verify - outbound' )
+    assert_equal( ticket.last_contact_customer.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact_customer verify - outbound' )
+    assert_equal( ticket.last_contact_agent.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent verify - outbound' )
+    assert_equal( ticket.first_response.to_s, article_outbound.created_at.to_s, 'ticket.first_response verify - outbound' )
+    assert_equal( ticket.close_time, nil, 'ticket.close_time verify - outbound' )
+
+    # create inbound article #3
+    article_inbound3 = Ticket::Article.create(
+      ticket_id: ticket.id,
+      from: 'some_sender@example.com',
+      to: 'some_recipient@example.com',
+      subject: 'some subject',
+      message_id: 'some@id',
+      body: 'some message article_inbound3 😍😍😍',
+      internal: false,
+      sender: Ticket::Article::Sender.where(name: 'Customer').first,
+      type: Ticket::Article::Type.where(name: 'email').first,
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+    assert_equal( article_inbound3.body, 'some message article_inbound3 😍😍😍'.utf8_to_3bytesutf8, 'article_inbound.body verify - inbound' )
+
+    ticket = Ticket.find(ticket.id)
+    assert_equal( ticket.article_count, 5, 'ticket.article_count verify - inbound' )
+    assert_equal( ticket.last_contact.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact verify - inbound' )
+    assert_equal( ticket.last_contact_customer.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact_customer verify - inbound' )
+    assert_equal( ticket.last_contact_agent.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent verify - outbound' )
+    assert_equal( ticket.first_response.to_s, article_outbound.created_at.to_s, 'ticket.first_response verify - outbound' )
+    assert_equal( ticket.close_time, nil, 'ticket.close_time verify - outbound' )
+
+    # create inbound article #4
+    sleep 2
+    article_inbound4 = Ticket::Article.create(
+      ticket_id: ticket.id,
+      from: 'some_sender@example.com',
+      to: 'some_recipient@example.com',
+      subject: 'some subject',
+      message_id: 'some@id',
+      body: 'some message article_inbound4 😍😍😍',
+      internal: false,
+      sender: Ticket::Article::Sender.where(name: 'Customer').first,
+      type: Ticket::Article::Type.where(name: 'email').first,
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+    assert_equal( article_inbound4.body, 'some message article_inbound4 😍😍😍'.utf8_to_3bytesutf8, 'article_inbound.body verify - inbound' )
+
+    ticket = Ticket.find(ticket.id)
+    assert_equal( ticket.article_count, 6, 'ticket.article_count verify - inbound' )
+    assert_equal( ticket.last_contact.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact verify - inbound' )
+    assert_equal( ticket.last_contact_customer.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact_customer verify - inbound' )
     assert_equal( ticket.last_contact_agent.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent verify - outbound' )
     assert_equal( ticket.first_response.to_s, article_outbound.created_at.to_s, 'ticket.first_response verify - outbound' )
     assert_equal( ticket.close_time, nil, 'ticket.close_time verify - outbound' )
@@ -93,9 +167,9 @@ class TicketTest < ActiveSupport::TestCase
     ticket.save
 
     ticket = Ticket.find(ticket.id)
-    assert_equal( ticket.article_count, 3, 'ticket.article_count verify - state update' )
-    assert_equal( ticket.last_contact.to_s, article_outbound.created_at.to_s, 'ticket.last_contact verify - state update' )
-    assert_equal( ticket.last_contact_customer.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer verify - state update' )
+    assert_equal( ticket.article_count, 6, 'ticket.article_count verify - state update' )
+    assert_equal( ticket.last_contact.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact verify - state update' )
+    assert_equal( ticket.last_contact_customer.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact_customer verify - state update' )
     assert_equal( ticket.last_contact_agent.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent verify - state update' )
     assert_equal( ticket.first_response.to_s, article_outbound.created_at.to_s, 'ticket.first_response verify - state update' )
     assert( ticket.close_time, 'ticket.close_time verify - state update' )