fix: fixes issue with SMTP sender with address endpoints

spec/lib/message_dequeuer/incoming_message_processor_spec.rb

@@ -434,7 +434,7 @@ module MessageDequeuer
       it "gets a sender from the state and sends the message to it" do
         smtp_sender_double = double("SMTPSender")
         expect(smtp_sender_double).to receive(:send_message).with(queued_message.message).and_return(SendResult.new)
-        expect(state).to receive(:sender_for).with(SMTPSender, endpoint.domain, nil, { force_rcpt_to: endpoint.address }).and_return(smtp_sender_double)
+        expect(state).to receive(:sender_for).with(SMTPSender, endpoint.domain, nil, { rcpt_to: endpoint.address }).and_return(smtp_sender_double)
         processor.process
       end
     end