Merge branch '5988-info-requests-in-headers' into develop

app/mailers/request_mailer.rb

@@ -231,9 +231,7 @@ def self.receive(raw_email, source = :mailin)
 
   # Find which info requests the email is for
   def requests_matching_email(email)
-    # We deliberately don't use Envelope-to here, so ones that are BCC
-    # drop into the holding pen for checking.
-    addresses = ((email.to || []) + (email.cc || [])).compact
+    addresses = MailHandler.get_all_addresses(email)
     InfoRequest.matching_incoming_email(addresses)
   end
 
@@ -244,8 +242,8 @@ def receive(email, raw_email, source = :mailin)
     # Find which info requests the email is for
     reply_info_requests = requests_matching_email(email)
 
-    # Nothing found, so save in holding pen
-    if reply_info_requests.empty?
+    # Nothing found OR multiple different info requests, so save in holding pen
+    if reply_info_requests.empty? || reply_info_requests.count > 1
       opts[:rejected_reason] =
         _("Could not identify the request from the email address")
       request = InfoRequest.holding_pen_request

lib/mail_handler/backends/mail_backend.rb

@@ -146,6 +146,7 @@ def get_all_addresses(mail, include_invalid: false)
         addrs << mail.bcc
         addrs << mail[:bcc].try(:value) if mail.bcc.nil? && include_invalid
         addrs << (mail['envelope-to'] ? mail['envelope-to'].value.to_s : nil)
+        addrs << get_emails_within_received_headers(mail)
         addrs.flatten.compact.uniq
       end
 
@@ -396,6 +397,15 @@ def address_from_string(string)
         mail.from = string
         mail.from[0]
       end
+
+      def get_emails_within_received_headers(email)
+        received_headers = Array(email['Received'])
+        return [] if received_headers.empty?
+        received_headers.map(&:to_s).
+          join(' ').
+          scan(MySociety::Validate.email_find_regexp).
+          flatten
+      end
     end
   end
 end

spec/lib/mail_handler/backends/mail_backend_spec.rb

@@ -322,4 +322,88 @@
       expect { decode_attached_part(mail.parts.last, mail) }.not_to raise_error
     end
   end
+
+  describe :get_emails_within_received_headers do
+
+    it 'returns an empty list if there is no Received header' do
+      mail = get_fixture_mail('bcc-contact-reply.email')
+      expect(get_emails_within_received_headers(mail)).to eq([])
+    end
+
+    it 'returns an empty list if the Received header contains no email addresses' do
+      mail = Mail.new(<<~EOF.strip_heredoc)
+        From: "FOI Person" <foiperson@localhost>
+        To: "Bob Smith" <bob@localhost>
+        Cc: [email protected]
+        Envelope-To: [email protected]
+        Received: abc id abc from notAnEmail
+        Date: Tue, 13 Nov 2007 11:39:55 +0000
+        Bcc: "BCC Person" <bccperson@localhost>
+        Subject: Test
+        Reply-To:
+
+        Test
+      EOF
+
+      expect(get_emails_within_received_headers(mail)).to eq([])
+    end
+
+    it 'returns a list containing the email if the Received header contains one email address' do
+      mail = Mail.new(<<~EOF.strip_heredoc)
+        From: "FOI Person" <foiperson@localhost>
+        To: "Bob Smith" <bob@localhost>
+        Cc: [email protected]
+        Envelope-To: [email protected]
+        Received: abc id abc from [email protected]
+        Date: Tue, 13 Nov 2007 11:39:55 +0000
+        Bcc: "BCC Person" <bccperson@localhost>
+        Subject: Test
+        Reply-To:
+
+        Test
+      EOF
+
+      expect(get_emails_within_received_headers(mail)).
+        to eq(['[email protected]'])
+    end
+
+    it 'returns a (single dimensional) list containing the emails if the Received header contains multiple email addresses' do
+      mail = Mail.new(<<~EOF.strip_heredoc)
+        From: "FOI Person" <foiperson@localhost>
+        To: "Bob Smith" <bob@localhost>
+        Cc: [email protected]
+        Envelope-To: [email protected]
+        Received: abc id abc from [email protected]
+          also there is [email protected]
+        Date: Tue, 13 Nov 2007 11:39:55 +0000
+        Bcc: "BCC Person" <bccperson@localhost>
+        Subject: Test
+        Reply-To:
+
+        Test
+      EOF
+
+      expect(get_emails_within_received_headers(mail)).
+        to eq(['[email protected]', '[email protected]'])
+    end
+
+    it 'recognises the Received header when it is not capitalised' do
+      mail = Mail.new(<<~EOF.strip_heredoc)
+        From: "FOI Person" <foiperson@localhost>
+        To: "Bob Smith" <bob@localhost>
+        Cc: [email protected]
+        Envelope-To: [email protected]
+        received: abc id abc from [email protected]
+        Date: Tue, 13 Nov 2007 11:39:55 +0000
+        Bcc: "BCC Person" <bccperson@localhost>
+        Subject: Test
+        Reply-To:
+
+        Test
+      EOF
+
+      expect(get_emails_within_received_headers(mail)).
+        to eq(['[email protected]'])
+    end
+  end
 end

spec/mailers/request_mailer_spec.rb

@@ -48,12 +48,29 @@
       expect(InfoRequest.holding_pen_request.incoming_messages.count).to eq(1)
     end
 
-    it "puts messages with the request address in Bcc: in the holding pen" do
-      request = FactoryBot.create(:info_request)
-      receive_incoming_mail('bcc-contact-reply.email',
-                            email_to: 'dummy@localhost',
-                            email_bcc: request.incoming_email)
-      expect(InfoRequest.holding_pen_request.incoming_messages.count).to eq(1)
+
+    it "attaches messages with an info request address in the Received headers to the appropriate request" do
+      ir = info_requests(:fancy_dog_request)
+      expect(ir.incoming_messages.count).to eq(1) # in the fixture
+      mail_content = <<~EOF
+        From: "FOI Person" <foiperson@localhost>
+        Received: from smtp-out.localhost
+                by example.net with esmtps
+                (Exim 4.89)
+                (envelope-from <[email protected]>)
+                id ABC
+                for #{ir.incoming_email}.com; Mon, 23 Nov 2020 00:00:00 +0000
+        Test
+      EOF
+      receive_incoming_mail(mail_content)
+      expect(ir.incoming_messages.count).to eq(2) # one more arrives
+      expect(ir.info_request_events[-1].incoming_message_id).not_to be_nil
+
+      deliveries = ActionMailer::Base.deliveries
+      expect(deliveries.size).to eq(1)
+      mail = deliveries[0]
+      expect(mail.to).to eq([ 'bob@localhost' ]) # to the user who sent fancy_dog_request
+      deliveries.clear
     end
 
     it "puts messages with multiple request addresses in Bcc: in the holding pen" do