c# - smtpClient.SendAsync：电子邮件永远不会到达 C#

Question

SmtpClient Client = new SmtpClient(SMTPClientHostName, 25)
{
      EnableSsl = true,
      Timeout = 30000,
      DeliveryMethod = SmtpDeliveryMethod.Network,
      UseDefaultCredentials = false,
      Credentials = new System.Net.NetworkCredential(SenderEmailAddress, SenderEmailAddressPassword)
};

Object Object = MailMessage;

Client.SendCompleted += new SendCompletedEventHandler(SMTPClient_SendCompleted);

Client.SendAsync(MailMessage, Object);

我正在尝试通过 SendAsync 发送电子邮件。它永远不会到达。

事件：

private static void SMTPClient_SendCompleted(object Sender, System.ComponentModel.AsyncCompletedEventArgs AsyncCompletedEvent)
{
   MailMessage MailMessage = AsyncCompletedEvent.UserState as MailMessage;
}

我发送它已经十分钟了。消息确实通过 Send 到达。

这里有什么问题？

更新：我的代码包含使用；在我删除它后，电子邮件开始到达。有谁知道为什么？