Handle incoming emails from aliases correctly

These set the 'actual' destination email in one of the Delivered-To lines, so
check those too.

1 files changed, 11 insertions, 5 deletions

diff --git a/lib/gitlab/email/receiver.rb b/lib/gitlab/email/receiver.rb
index c270c0ea9ff..0d6b08b5d29 100644
--- a/lib/gitlab/email/receiver.rb
+++ b/lib/gitlab/email/receiver.rb
@@ -57,9 +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)
@@ -75,12 +74,19 @@ module Gitlab
         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