Selenium Parametrization - selenium-webdriver

Question

I have tried this following code to automate gmail,in the first function the browser is able to get the element till "Compose" and click on it but the next few elements like "to" , "subject" is not found ..i have specified the next elements in void mailSend() function , i am not sure why it does not read the next elements.
public class Example{
public static WebDriver driver;
#BeforeClass
public void before()
{
driver = new FirefoxDriver();
}
#Test(dataProvider = "Data-Provider-Function")
public void startup(String uName,String pass) throws Exception
{
driver.get("https://www.gmail.com");
driver.findElement(By.id("Email")).sendKeys(uName);
driver.findElement(By.id("Passwd")).sendKeys(pass);
driver.findElement(By.id("signIn")).click();
Thread.sleep(4000);
driver.findElement(By.cssSelector("div[class='T-I J-J5-Ji T-I-" +
"KE L3']")).click();
Thread.sleep(4000);
}
#DataProvider (name = "Data-Provider-Function")
public Object[][] startupProvider()
{
return new Object[][]
{
{"selva.prokarma.test#gmail.com", "prokarma"}
};
}
#Test(dataProvider="Mail Information")
public void mailSend(String to,String subject,String body) throws Exception
{
driver.navigate().refresh();
Thread.sleep(2000);
driver.findElement(By.className("vO")).sendKeys(to);
Thread.sleep(2000);
driver.findElement(By.className("aoT")).sendKeys(subject);
Thread.sleep(2000);
driver.findElement(By.cssSelector(".editable")).click();
driver.switchTo().frame(driver.findElement(By.xpath("//iframe[contains(#tabindex,'1') and contains(#frameborder,'0')]")));
driver.findElement(By.xpath("//body[#role='textbox']")).sendKeys(body);
driver.switchTo().defaultContent();
driver.findElement(By.cssSelector("div[class='T-I J-J5-Ji aoO T-I-atl L3']")).click();
Thread.sleep(4000);
driver.navigate().refresh();
Thread.sleep(4000);
}
#DataProvider (name = "Mail Information")
public Object[][] mailSendProvider()
{
return new Object[][]
{
{"selva.prokarma.test#gmail.com", "This is a Test Mail","Prokarma"},
{"selva.prokarma.test#gmail.com", "This is Test Mail 2","Hello Automation King "},
{"selva.prokarma.test#gmail.com","This is another Test Mail 3","Hello Selva"},
{"selva.prokarma.test#gmail.com","This is another Test Mail 3","Hello SelvaKumar"},
{"selva.prokarma.test#gmail.com","Hi How are you doing","Robotium Tasks to be followed"}
};
}
#AfterClass
public void tear()
{
driver.quit();
}
}

Answer 1

I kept the wait as 60 secs and removed all sleep statements which are not at all required. and More over i tried everything in single test method.
public class Example2 {
public static WebDriver driver;
#BeforeClass
public void before()
{
driver = new FirefoxDriver();
driver.manage().timeouts().implicitlyWait(60000, TimeUnit.MILLISECONDS);
}
#Test(dataProvider="Mail Information")
public void mailSend(String to,String subject,String body) throws Exception
{
driver.get("https://www.gmail.com");
driver.findElement(By.id("Email")).sendKeys("xyzy#gmail.com");
driver.findElement(By.id("Passwd")).sendKeys("*********");
driver.findElement(By.id("signIn")).click();
driver.findElement(By.cssSelector("div[class='T-I J-J5-Ji T-I-KE L3']")).click();
driver.findElement(By.className("vO")).sendKeys(to);
driver.findElement(By.className("aoT")).sendKeys(subject);
driver.findElement(By.cssSelector(".editable")).click();
driver.switchTo().frame(driver.findElement(By.xpath("//iframe[contains(#tabindex,'1') and contains(#frameborder,'0')]")));
driver.findElement(By.xpath("//body[#role='textbox']")).sendKeys(body);
driver.switchTo().defaultContent();
driver.findElement(By.cssSelector("div[class='T-I J-J5-Ji aoO T-I-atl L3']")).click();
driver.navigate().refresh();
}
#DataProvider (name = "Mail Information")
public Object[][] mailSendProvider()
{
return new Object[][]
{
{"xyzy#gmail.com", "This is a Test Mail","hello"},
};
}
#AfterClass
public void tear()
{
driver.quit();
}
Attaching the output screenshot as well...