3 files changed, 10 insertions, 10 deletions
diff --git a/app/mailers/notify.rb b/app/mailers/notify.rb
index 44df3d6407d..c2ea99d9688 100644
--- a/app/mailers/notify.rb
+++ b/app/mailers/notify.rb
@@ -146,7 +146,7 @@ class Notify < ActionMailer::Base
 
     if reply_key
       headers['X-GitLab-Reply-Key'] = reply_key
-      headers['Reply-To'] = Gitlab.config.reply_by_email.address.gsub('%{reply_key}', reply_key)
+      headers['Reply-To'] = Gitlab::ReplyByEmail.reply_address(reply_key)
     end
 
     mail(headers)
@@ -165,6 +165,10 @@ class Notify < ActionMailer::Base
     headers['In-Reply-To'] = message_id(model)
     headers['References'] = message_id(model)
 
+    if headers[:subject]
+      headers[:subject].prepend('Re: ')
+    end
+
     mail_new_thread(model, headers)
   end
 
@@ -173,8 +177,6 @@ class Notify < ActionMailer::Base
   end
 
   def reply_key
-    return nil unless Gitlab.config.reply_by_email.enabled
-
-    @reply_key ||= SecureRandom.hex(16)
+    @reply_key ||= Gitlab::ReplyByEmail.reply_key
   end
 end
diff --git a/app/models/sent_notification.rb b/app/models/sent_notification.rb
index a3d24669b52..23a1b19ea7c 100644
--- a/app/models/sent_notification.rb
+++ b/app/models/sent_notification.rb
@@ -6,8 +6,8 @@ class SentNotification < ActiveRecord::Base
   validate :project, :recipient, :reply_key, presence: true
   validate :reply_key, uniqueness: true
 
-  validates :noteable_id, presence: true, if: ->(n) { n.noteable_type.present? && n.noteable_type != 'Commit' }
-  validates :commit_id, presence: true, if: ->(n) { n.noteable_type == 'Commit' }
+  validates :noteable_id, presence: true, unless: :for_commit?
+  validates :commit_id, presence: true, if: :for_commit?
 
   def self.for(reply_key)
     find_by(reply_key: reply_key)
@@ -19,11 +19,9 @@ class SentNotification < ActiveRecord::Base
 
   def noteable
     if for_commit?
-      project.commit(commit_id)
+      project.commit(commit_id) rescue nil
     else
       super
     end
-  rescue
-    nil
   end
 end
diff --git a/app/workers/email_receiver_worker.rb b/app/workers/email_receiver_worker.rb
index e44a430f6bc..94e346b5a51 100644
--- a/app/workers/email_receiver_worker.rb
+++ b/app/workers/email_receiver_worker.rb
@@ -4,7 +4,7 @@ class EmailReceiverWorker
   sidekiq_options queue: :incoming_email
 
   def perform(raw)
-    return unless Gitlab.config.reply_by_email.enabled
+    return unless Gitlab::ReplyByEmail.enabled?
 
     # begin
       Gitlab::EmailReceiver.new(raw).process