关于ASP。NET发送HTML格式的邮件

 using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Net.Mail;
using System.Net;

public partial class sendmail : System.Web.UI.Page
{
    private static  string smtpserver="smtp.126.com";
    private static string serveremail="z***g758@126.com";
    private static string serverpass="*6****5";
    private static int port=25;
    private static bool ssl=false;
    public static bool sendgmail(string mailto,string subject,string body)
    {
        SmtpClient mail=new SmtpClient(smtpserver,port);
        mail.UseDefaultCredentials=true;
        mail.Credentials=new System.Net.NetworkCredential(serveremail,serverpass);
        mail.DeliveryMethod=SmtpDeliveryMethod.Network;
        mail.EnableSsl=ssl;
        MailMessage message=new MailMessage(serveremail,mailto,subject,body);
        message.SubjectEncoding=System.Text.Encoding.GetEncoding("gb2312");
             message.BodyEncoding = System.Text.Encoding.GetEncoding("gb2312");
             message.IsBodyHtml = true;
        try
        {
            mail.Send(message);
            return true;
           
        }
        catch(Exception e)
        {
            System.Web.HttpContext.Current.Response.Write(e.Message);
            return false;
        }
     }
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void send_Click(object sender, EventArgs e)
    {
        sendgmail(to.Text, subject.Text, content.Text);
    }
}