用C#发送邮件

using System;
using System.Collections.Generic;
using System.Text;
using System.Web.Mail;
using System.IO;

namespace Mail
{
public class Mail
{
string from;

public string From
{
get { return from; }
set { from = value; }
}
string to;

public string To
{
get { return to; }
set { to = value; }
}
string stmpServer;
string password;
string subject;

public string Subject
{
get { return subject; }
set { subject = value; }
}
string body;

public string Body
{
get { return body; }
set { body = value; }
}

string attachment;

public string Attachment
{
get { return attachment; }
set { attachment = value; }
}
static MailMessage mailMessage;
public static void setMail(string from,string password,string stmpServer)
{
mailMessage = new MailMessage();
mailMessage.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1");
mailMessage.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", from);
mailMessage.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", password);
SmtpMail.SmtpServer = stmpServer;
}
public string Send()
{
if (from != null && from != "" && from.IndexOf("@") != -1)
Mail.mailMessage.From = from;
else
return "无效的发件人邮件！";
if (to != null && to != "" && to.IndexOf("@") != -1)
Mail.mailMessage.To = to;
else
return "无效的收件人邮件！";
if (subject != null)
Mail.mailMessage.Subject = subject;
else
Mail.mailMessage.Subject = "无标题";
if (body != null)
Mail.mailMessage.Body = body;
else
Mail.mailMessage.Body = "";
if (attachment != "" && attachment != null)
Mail.mailMessage.Attachments.Add(new MailAttachment(attachment));

Mail.mailMessage.BodyFormat = MailFormat.Html;
try
{
SmtpMail.Send(mailMessage);
return "邮件发送成功！";
}
catch (Exception ex)
{
return ex.Message;
throw ex;
}
}
}
}