一个通过web.Mail发送邮件的类 

using System;
using System.Web;
using System.Web.Mail;
using Dottext.Framework;
using Dottext.Framework.Configuration;

namespace YourNamespace.Email
{
 /// <summary>
 /// Default implementation of the IMailProvider
 /// </summary>
 public class SystemMail : IMailProvider
 {
  public SystemMail(){}

  #region
  private string _to;
  public string To
  {
   get{return _to;}
   set{_to = value;}
  }

  private string _from;
  public string From
  {
   get{return _from;}
   set{_from = value;}
  }

  private string _subject;
  public string Subject
  {
   get{return _subject;}
   set{_subject = value;}
  }

  private string _body;
  public string Body
  {
   get{return _body;}
   set{_body = value;}
  }
  #endregion

  private string _adminEmail;
  public string AdminEmail
  {
   get{return _adminEmail;}
   set{_adminEmail = value;}
  }

  private string _smtpServer = "localhost";
  public string SmtpServer
  {
   get{return _smtpServer;}
   set{_smtpServer = value;}
  }

  private string _password;
  public string Password
  {
   get{return _password;}
   set{_password = value;}
  }

  private string _userName;
  public string UserName
  {
   get{return _userName;}
   set{_userName = value;}
  }

  public bool Send(string to, string from, string subject, string message)
  {
   try
   {
    MailMessage em = new MailMessage();
    em.To = to;
    em.From = from;
    em.Subject = subject;
    em.Body = message;

    //Found out how to send authenticated email via System.Web.Mail at http://SystemWebMail.com (fact 3.8)
    if(this.UserName != null && this.Password != null)
    {
     em.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1"); //basic authentication
     em.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", this.UserName); //set your username here
     em.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", this.Password); //set your password here
     
    }

    SmtpMail.SmtpServer = this.SmtpServer;
    SmtpMail.Send(em);
    
    return true;
   }
   catch
   {
    return false;
   }
  }

 }
}