EWS发送邮件问题

[hs3933046]

公司是exchang邮箱，现在要发送邮件使用Microsoft.Exchange.WebServices，发送邮件的代码如下
public void Send_email(object sender, EventArgs e)
{
// Hook up the cert callback.
ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2010);
service.Credentials = new WebCredentials("piccad.intra\\ceshi", "123456");
service.Url = new Uri("https://email.picc.com.cn/ews/Exchange.asmx");

EmailMessage message = new EmailMessage(service);
message.Subject = "Hello world";
message.Body = new MessageBody();
message.Body.BodyType = BodyType.Text;
message.Body.Text = "测试！";
message.ToRecipients.Add("[e-mail]");
message.SendAndSaveCopy();

}
现在在发送那里一直报 远程服务器返回错误: (401) 未经授权，有哪位大神知道原因吗 ？

[hs3933046]

自己给自己结贴吧，报未经授权是因为用户名那里不能接域名。。。使用用户名就行了