fix: find mail message by references (#7220)

app/mailboxes/imap/imap_mailbox.rb

@@ -35,9 +35,9 @@ class Imap::ImapMailbox
   end
 
   def find_conversation_by_in_reply_to
-    return if in_reply_to.blank?
+    return if in_reply_to.blank? && @inbound_mail.references.blank?
 
-    message = @inbox.messages.find_by(source_id: in_reply_to)
+    message = @inbox.messages.find_by(source_id: in_reply_to) || find_message_by_references
     if message.nil?
       @inbox.conversations.where("additional_attributes->>'in_reply_to' = ?", in_reply_to).first
     else
@@ -49,6 +49,20 @@ class Imap::ImapMailbox
     @inbound_mail.in_reply_to
   end
 
+  def find_message_by_references
+    message_to_return = nil
+
+    return if @inbound_mail.references.blank?
+
+    references = @inbound_mail.references
+
+    references.each do |message_id|
+      message = @inbox.messages.find_by(source_id: message_id)
+      message_to_return = message if message.present?
+    end
+    message_to_return
+  end
+
   def find_or_create_conversation
     @conversation = find_conversation_by_in_reply_to || ::Conversation.create!({ account_id: @account.id,
                                                                                  inbox_id: @inbox.id,

spec/fixtures/files/references.eml

@@ -0,0 +1,16 @@
+From: Sony Mathew <sony@chatwoot.com>
+Mime-Version: 1.0 (Apple Message framework v1244.3)
+Content-Type: multipart/alternative; boundary="Apple-Mail=_33A037C7-4BB3-4772-AE52-FCF2D7535F74"
+Subject: Discussion: Let's debate these attachments
+Date: Tue, 20 Apr 2020 04:20:20 -0400
+In-Reply-To: <4e6e35f5a38b4_479f13bb90078178@small-app-01.mail>
+References: <4e6e35f5a38b4_479f13bb90078178@small-app-01.mail> <test-reference-id>
+Message-Id: <0CB459E0-0336-41DA-BC88-E6E28C697DDBF@chatwoot.com>
+X-Mailer: Apple Mail (2.1244.3)
+
+--Apple-Mail=_33A037C7-4BB3-4772-AE52-FCF2D7535F74
+Content-Transfer-Encoding: quoted-printable
+Content-Type: text/plain;
+  charset=utf-8
+
+References Email

spec/mailboxes/imap/imap_mailbox_spec.rb

@@ -83,11 +83,34 @@ RSpec.describe Imap::ImapMailbox do
       let(:reply_mail) do
         create_inbound_email_from_mail(from: 'email@gmail.com', to: 'imap@gmail.com', subject: 'Hello!', in_reply_to: 'test-in-reply-to')
       end
+      let(:references_email) { create_inbound_email_from_fixture('references.eml') }
 
       it 'creates new email conversation with incoming in-reply-to' do
         class_instance.process(reply_mail.mail, channel)
         expect(conversation.additional_attributes['in_reply_to']).to eq(reply_mail.mail.in_reply_to)
       end
+
+      it 'append email to conversation with references id' do
+        inbox = Inbox.last
+        message = create(
+          :message,
+          content: 'Incoming Message',
+          message_type: 'incoming',
+          inbox: inbox,
+          source_id: 'test-reference-id',
+          account: account,
+          conversation: conversation
+        )
+        conversation = message.conversation
+
+        expect(conversation.messages.size).to eq(1)
+
+        class_instance.process(references_email.mail, inbox.channel)
+
+        expect(conversation.messages.size).to eq(2)
+        expect(conversation.messages.last.content).to eq('References Email')
+        expect(references_email.mail.references).to include('test-reference-id')
+      end
     end
   end
 end