CDO.MessageClass cMsg=new CDO.MessageClass();
cMsg.DataSource.Open(url,null,ADODB.ConnectModeEnum.adModeRead,ADODB.RecordCreateOptionsEnum.adFailIfNotExists,ADODB.RecordOpenOptionsEnum.adOpenSource,Session["UserAccountName"].ToString(),Session["UserPwd"].ToString()); 
ADODB.Stream stm = new ADODB.StreamClass();
stm = cMsg.Attachments[1].GetStream();把附件赋给Stream对象后,要在怎样才能以字节方式输出到客户端让用户下载呢,苦苦得不到结果!