public void UploadFile()
{
string File = "UploadTEST.txt";
string FilePath = @"C:\Users\Lenovo Y500\Desktop\" + File;
EmailPage emailPage = new EmailPage(driver);
emailPage.CreateLetterBtn().Click();
emailPage.ReceiverField().SendKeys("*****@*****.**");
emailPage.SubjectField().SendKeys("Letter for test");
emailPage.DescriptionField().SendKeys("Description Test");
driver.FindElement(By.XPath("//*[@id='att']/div[2]/span[1]/i")).Click();
Thread.Sleep(2000);
driver.FindElement(By.XPath("//input[@type='file']")).SendKeys(FilePath);
Thread.Sleep(2000);
emailPage.SentMailButton().Click();
emailPage.IncomingMailsTab().Click();
emailPage.FirstMail().Click();
}