diff --git a/app/models/observer/ticket/article/fillup_from_email.rb b/app/models/observer/ticket/article/fillup_from_email.rb
index 55bbbdc98..d0735373b 100644
--- a/app/models/observer/ticket/article/fillup_from_email.rb
+++ b/app/models/observer/ticket/article/fillup_from_email.rb
@@ -30,6 +30,9 @@ class Observer::Ticket::Article::FillupFromEmail < ActiveRecord::Observer
     fqdn = Setting.get('fqdn')
     record.message_id = '<' + DateTime.current.to_s(:number) + '.' + record.ticket_id.to_s + '.' + rand(999_999).to_s() + '@' + fqdn + '>'
 
+    # generate message_id_md5
+    record.check_message_id_md5
+
     # set sender
     email_address = ticket.group.email_address
     if !email_address
diff --git a/app/models/ticket/article.rb b/app/models/ticket/article.rb
index 194bc89d4..66096a282 100644
--- a/app/models/ticket/article.rb
+++ b/app/models/ticket/article.rb
@@ -30,6 +30,13 @@ class Ticket::Article < ApplicationModel
     preferences: true,
   }
 
+  # fillup md5 of message id to search easier on very long message ids
+  def check_message_id_md5
+    return if !message_id
+    return if message_id_md5
+    self.message_id_md5 = Digest::MD5.hexdigest(message_id.to_s)
+  end
+
   private
 
   # strip not wanted chars
@@ -38,13 +45,6 @@ class Ticket::Article < ApplicationModel
     subject.gsub!(/\s|\t|\r/, ' ')
   end
 
-  # fillup md5 of message id to search easier on very long message ids
-  def check_message_id_md5
-    return if !message_id
-    return if message_id_md5
-    self.message_id_md5 = Digest::MD5.hexdigest(message_id.to_s)
-  end
-
   class Flag < ApplicationModel
   end