@Mock EmailService emailServiceMock; @Test public void sendEmailTest() { String[] recepients = new String[0]; String from = "from"; String subject = "subject"; String templateName = "templateName"; Map<String, Object> params = Collections.emptyMap(); String nullString = null; Integer nullInteger = null; when(emailServiceMock.sendEmail(recepients, from, subject, templateName, params)).thenCallRealMethod(); when(emailServiceMock.sendMail(recepients, from, subject, templateName, nullString, params, nullString, nullInteger)).thenReturn(true); emailServiceMock.sendEmail(recepients, from, subject, templateName, params); Mockito.verify(emailServiceMock).sendMail(eq(recepients), eq(from), eq(subject), eq(templateName), eq(nullString), eq(params), eq(nullString), eq(nullInteger)); }