asp.net 邮件发送类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mail;

/// <summary>
///mailhelper 的摘要说明
/// </summary>
public class mailhelper
{
    public mailhelper()
    {
        //
        //TODO: 在此处添加构造函数逻辑
        //
    }

    /// <summary>
    /// 邮件发送操作
    /// </summary>
    /// <param name="Addressee">收件人地址</param>
    /// <param name="From">发件人地址</param>
    /// <param name="sendpassword">发件人密码</param>
    /// <param name="Copy">抄送人地址</param>
    /// <param name="secret">密送人地址</param>
    /// <param name="Subject">发送主题</param>
    /// <param name="Attachment">附件信息</param>
    /// <param name="Body">邮件内容</param>
    public string SendeEmal(string Addressee, string From, string sendpassword, string Copy, string secret, string Subject, string Attachment, string Body)
    {
        MailMessage objMailMessage;
        MailAttachment objMailAttachment;


        // 创建邮件消息
        objMailMessage = new MailMessage();

        //发件人EMAIL
        objMailMessage.From = From;//源邮件地址

        //收件人EMAIL
        objMailMessage.To = Addressee; //目的邮件地址
        //邮件抄送
        objMailMessage.Cc = Copy;
        //邮件misong
        objMailMessage.Bcc = secret;


        //邮件主题
        objMailMessage.Subject = Subject; //发送邮件的标题

        //邮件内容
        objMailMessage.Body = Body;//发送邮件的内容

        // 创建一个附件对象
        if (Attachment != "")
        {
            objMailAttachment = new MailAttachment(Attachment);//发送邮件的附件 c:\test.txt
            objMailMessage.Attachments.Add(objMailAttachment);//将附件附加到邮件消息对象中
        }

        //接着利用SMTP来发送邮件，需要使用Microsoft .NET Framework SDK v1.1和它以上的版本
        //基本权限
        objMailMessage.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1");
        //用户名
        string name = From.Substring(0, From.IndexOf('@'));
        objMailMessage.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", name);
        //密码
        objMailMessage.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", sendpassword);
        //如果没有上述三行代码，则出现如下错误提示：服务器拒绝了一个或多个收件人地址。服务器响应为: 554 : Client host rejected: Access denied
        //SMTP地址      
        string smtp = "smtp." + From.Substring(From.IndexOf('@') + 1);
        SmtpMail.SmtpServer = "smtp." + From.Substring(From.IndexOf('@') + 1);
        //开始发送邮件

        try
        {
            SmtpMail.Send(objMailMessage);
            return "邮件发送成功！";
        }
        catch (System.Net.Mail.SmtpException ex)
        {
            return ex.Message;
        }
        //核心代码结束
    }
}