Merge remote-tracking branch 'upstream/master' into 27377-preload-pipeline-entity27377-preload-pipeline-entity

* upstream/master: (2534 commits)
  Update VERSION to 9.3.0-pre
  Update CHANGELOG.md for 9.2.0
  removes unnecessary redundacy in usage ping doc
  Respect the typo as rubocop said
  Add a test to ensure this works on MySQL
  Change pipelines schedules help page path
  change domain to hostname in usage ping doc
  Fixes broken MySQL migration for retried
  Show password field mask while editing service settings
  Add notes for supported schedulers and cloud providers
  Move environment monitoring to environments doc
  Add docs for change of Cache/Artifact restore order"
  Avoid resource intensive login checks if password is not provided
  Change translation for 'coding' by 'desarrollo' for Spanish
  Add to docs: issues multiple assignees
  rename "Add emoji" and "Award emoji" to "Add reaction" where appropriate
  Add project and group notification settings info
  32570 Fix border-bottom for project activity tab
  Add users endpoint to frontend API class
  Rename users on mysql
  ...

1 files changed, 15 insertions, 6 deletions

diff --git a/lib/gitlab/email/receiver.rb b/lib/gitlab/email/receiver.rb
index ec0529b5a4b..0d6b08b5d29 100644
--- a/lib/gitlab/email/receiver.rb
+++ b/lib/gitlab/email/receiver.rb
@@ -1,4 +1,3 @@
-
 require_dependency 'gitlab/email/handler'
 
 # Inspired in great part by Discourse's Email::Receiver
@@ -32,6 +31,8 @@ module Gitlab
 
         raise UnknownIncomingEmail unless handler
 
+        Gitlab::Metrics.add_event(:receive_email, handler.metrics_params)
+
         handler.execute
       end
 
@@ -56,9 +57,8 @@ module Gitlab
       end
 
       def key_from_additional_headers(mail)
-        references = ensure_references_array(mail.references)
-
-        find_key_from_references(references)
+        find_key_from_references(mail) ||
+          find_key_from_delivered_to_header(mail)
       end
 
       def ensure_references_array(references)
@@ -69,15 +69,24 @@ module Gitlab
           # Handle emails from clients which append with commas,
           # example clients are Microsoft exchange and iOS app
           Gitlab::IncomingEmail.scan_fallback_references(references)
+        when nil
+          []
         end
       end
 
-      def find_key_from_references(references)
-        references.find do |mail_id|
+      def find_key_from_references(mail)
+        ensure_references_array(mail.references).find do |mail_id|
           key = Gitlab::IncomingEmail.key_from_fallback_message_id(mail_id)
           break key if key
         end
       end
+
+      def find_key_from_delivered_to_header(mail)
+        Array(mail[:delivered_to]).find do |header|
+          key = Gitlab::IncomingEmail.key_from_address(header.value)
+          break key if key
+        end
+      end
     end
   end
 end