Java Spring email testing with GreenMail

Question

I am implementing tests for a service which sends a lot of emails. As a testing tool I selected GreenMail.

I'm doing like

@Rule
public GreenMailRule mail = new GreenMailRule(ServerSetupTest.SMTP);

@Autowired
MailService mailService;

@Before
public void setUp() {
    mail.setUser("[email protected]", "[email protected]", "password");
    mail.setUser("[email protected]", "[email protected]", "password").create();
    mail.setUser("[email protected]", "[email protected]", "p").create();
    mail.start();
}

@Test
public void test() {
  // sends mail from [email protected] to recipient1 and recipient2 using cc
  mailService.send();
  mail.setUser("[email protected]", "password");
  assertEquals(1, mail.getReceivedMessages().length);
}

However, I got 2 messages - for both recipients. I think that the reason is smtp based for posting not reading. However if use POP3, I receive no messages at all.

So how can I get messages for specific user?