diff --git a/app/models/mailer.rb b/app/models/mailer.rb
index f58a1c88d..be5032a63 100644
--- a/app/models/mailer.rb
+++ b/app/models/mailer.rb
@@ -71,6 +71,7 @@ class Mailer < ActionMailer::Base
 
   # Builds a mail for notifying user about a new issue
   def issue_add(user, issue)
+    headers['Priority'] = priority_for_header(issue)
     redmine_headers 'Project' => issue.project.identifier,
                     'Issue-Tracker' => issue.tracker.name,
                     'Issue-Id' => issue.id,
@@ -103,6 +104,7 @@ class Mailer < ActionMailer::Base
   # Builds a mail for notifying user about an issue update
   def issue_edit(user, journal)
     issue = journal.journalized
+    headers['Priority'] = priority_for_header(issue)
     redmine_headers 'Project' => issue.project.identifier,
                     'Issue-Tracker' => issue.tracker.name,
                     'Issue-Id' => issue.id,
@@ -763,6 +765,19 @@ class Mailer < ActionMailer::Base
     h.each {|k, v| headers["X-Redmine-#{k}"] = v.to_s}
   end
 
+  def priority_for_header(issue)
+    # IssuePriority#low? and IssuePriority#high? are not used for
+    # performance reasons
+    position_name = issue.priority.position_name.to_s
+    if position_name == 'default'
+      'normal'
+    elsif position_name.start_with?('high')
+      'urgent'
+    elsif position_name.start_with?('low')
+      'non-urgent'
+    end
+  end
+
   # Singleton class method is public
   class << self
     def token_for(object, user)
diff --git a/test/unit/mailer_test.rb b/test/unit/mailer_test.rb
index b25e17427..b1e5f4db3 100644
--- a/test/unit/mailer_test.rb
+++ b/test/unit/mailer_test.rb
@@ -210,6 +210,7 @@ class MailerTest < ActiveSupport::TestCase
     # List-Id should not include the display name "Redmine"
     assert_equal '<redmine.example.net>', mail.header['List-Id'].to_s
     assert_equal 'Bug', mail.header['X-Redmine-Issue-Tracker'].to_s
+    assert_equal 'non-urgent', mail.header['Priority'].to_s
   end
 
   def test_email_headers_should_include_sender
@@ -219,6 +220,24 @@ class MailerTest < ActiveSupport::TestCase
     assert_equal issue.author.login, mail.header['X-Redmine-Sender'].to_s
   end
 
+  def test_email_headers_should_include_priority
+    to_test = {
+      IssuePriority.find(4) => 'non-urgent', # Low
+      IssuePriority.find(5) => 'normal',     # Normal
+      IssuePriority.find(6) => 'urgent',     # High
+      IssuePriority.find(7) => 'urgent',     # Urgent
+      IssuePriority.find(8) => 'urgent',     # Immediate
+    }
+
+    issue = Issue.find(1)
+    to_test.each do |priority, expected|
+      issue.update_attribute :priority_id, priority.id
+      Mailer.deliver_issue_add(issue)
+      mail = last_email
+      assert_equal expected, mail.header['Priority'].to_s
+    end
+  end
+
   def test_plain_text_mail
     Setting.plain_text_mail = 1
     journal = Journal.find(2)