C# SmtpClient DisplayName 問題

[Fact] public async Task Should_Get_Chinese_From_Mail() { // Arrange const string displayName = "Test (x測x試x)"; var mail = new MailMessage { Subject = "測試小括號中文", Body = "有括號時中文會被消失", From = new MailAddress( "jakeuj@hotmail.com", displayName, Encoding.UTF8) }; mail.To.Add("jakeuj@gmail.com"); //Act using (var smtpClient = new SmtpClient("smtp.gmail.com", 587) { UseDefaultCredentials = false, EnableSsl = true, //這裡要填正確的帳號跟密碼 Credentials = new NetworkCredential("apikey", "apikeyvalue") }) { await smtpClient.SendMailAsync(mail); } //Assert _testOutputHelper.WriteLine(displayName); displayName.ShouldNotBeNull(); }