WinForm使用cdo.message做邮件发送程序，无法设置优先级

[wwangpping99]

在用cdo.message做邮件发送，用163邮箱给qq邮箱发邮件，怎么设置优先级。具体代码如下：

CDO.Message cdoMess = new CDO.Message();
cdoMess.From = "[e-mail]";
cdoMess.Subject = "哈哈";
cdoMess.TextBody = "很高兴";
cdoMess.To = "[e-mail]";
cdoMess.Fields["urn:schemas:mailheader:importance"].Value = "high";
cdoMess.Fields.Update();

CDO.IConfiguration iConfg;
ADODB.Fields oFields;
iConfg = cdoMess.Configuration;

oFields = iConfg.Fields;
oFields["http://schemas.microsoft.com/cdo/configuration/sendusing"].Value = 2;
oFields["http://schemas.microsoft.com/cdo/configuration/sendemailaddress"].Value = "[e-mail]";//
oFields["http://schemas.microsoft.com/cdo/configuration/smtpaccountname"].Value = "[e-mail]";//
oFields["http://schemas.microsoft.com/cdo/configuration/sendusername"].Value = "[e-mail]";//用户名
oFields["http://schemas.microsoft.com/cdo/configuration/sendpassword"].Value = "password"; //密码
oFields["http://schemas.microsoft.com/cdo/configuration/smtpauthenticate"].Value = 1; //验证方式 0不需验证 1代表BASIC认证 2代表NTLM验证方式
oFields["http://schemas.microsoft.com/cdo/configuration/smtpserver"].Value = "smtp.163.com"; //smtp主机名
oFields.Update();

try
{
cdoMess.Send();
cdoMess = null;
}
catch
{
}
finally
{
MessageBox.Show("发送成功！");
}
以上代码(用户名和密码不用理~)发送到有些邮箱可以正常显示优先级，已测试。但是163发到qq邮箱就不行了，请达人赐教，谢谢。