System.Net.WebProxy proxy = new System.Net.WebProxy("itgproxy.redmond.corp.microsoft.com:80"); proxy.Credentials = System.Net.CredentialCache.DefaultCredentials; System.Net.GlobalProxySelection.Select = proxy; MailMessage m = new MailMessage(); m.From = tbFrom.Text; m.To = tbTo.Text; m.Subject = tbSubject.Text; m.Body = tbBody.Text; //优先级 switch(ddlp.SelectedIndex) ...{ case 0: m.Priority = MailPriority.High; break; case 1: m.Priority = MailPriority.Low; break; default: m.Priority = MailPriority.Normal; break; } //格式 if(ddlp.SelectedIndex==0) m.BodyFormat = MailFormat.Text; else m.BodyFormat = MailFormat.Html; //以下设置服务器 if(tbServer.Text!="") ...{ //以下代码适用于Framework1.1以上版本。 //SmtpMail.SmtpServer = tbServer.Text;// m.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate",// "1"); //basic authentication// m.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername",// tbUserName.Text); //set your username here// m.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword",// tbPass.Text); //set your password here } //以下处理附件 string strFileName = FileSelect.PostedFile.FileName; if(strFileName!="") m.Attachments.Add(new MailAttachment(strFileName)); SmtpMail.Send(m);