.NET中用SMTP发邮件的两中方法总结

方法一

System.Web.Mail名字空间下的SmtpMail.Send(MailMessage mail)静态方法
这种方法最为简单，是.NET1.1中常用的方法，一般的SMTP服务都能支持。

方法二
System.Net.Mail名字空间下的SmtpClient.Send(MailMesasge mail)实例方法

这是.NET2.0里推荐的方法，它更加灵活，但写起来复杂一点。像Gmail这样需要SSL安全连接认证的，方法一是不行的。

两种方法代码示例：

/**//// <summary>
    /// Send e-mail hepler class
    /// </summary>
    public sealed class EmailHelper
    {
        public static void SendWebMail(IList<string> toList, IList<string> ccList, 
            string subject, string body)
        {
            System.Web.Mail.MailMessage mail = new System.Web.Mail.MailMessage();
            SmtpMail.SmtpServer = SystemConfig.SmtpServer;

            if (toList==null || toList.Count ==0)
            {
                throw new ArgumentNullException("toList can be null or empty.");
            }

            StringBuilder sb = new StringBuilder();

            foreach (string s in toList)
            {
                sb.Append(s);
                sb.Append(";");
            }
            mail.To = sb.ToString();

            sb.Remove(0, sb.Length);
            if (ccList != null && ccList.Count != 0)
            {
                foreach (string s in ccList)
                {
                    sb.Append(s);
                    sb.Append(";");
                }
            }
            mail.Cc = sb.ToString();
            
            //基本权限 
            mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", 
                "1");
            //用户名 
            mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", 
                SystemConfig.SenderUserId);
            //密码 
            mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword",
                SystemConfig.SenderPassword);

            mail.From = SystemConfig.SenderEmail;
            mail.Subject = subject;
            mail.BodyFormat = MailFormat.Html;
            mail.Body = body;
            
            SmtpMail.Send(mail);           
        }

        public static void SendNetMail(IList<string> toList, IList<string> ccList,
            string subject, string body)
        {
            System.Net.Mail.MailMessage mail = new System.Net.Mail.MailMessage();            

            if (toList == null || toList.Count == 0)
            {
                throw new ArgumentNullException("toList can be null or empty.");
            }        

            foreach (string s in toList)
            {
                mail.To.Add(s);
            }

            if (ccList!= null && ccList.Count != 0)
            {
                foreach (string s in ccList)
                {
                    mail.CC.Add(s);
                }
            }

            mail.From = new System.Net.Mail.MailAddress(SystemConfig.SenderEmail, SystemConfig.SenderUserId,Encoding.UTF8);
            mail.Subject = subject;
            mail.IsBodyHtml = true;
            mail.Body = body;

            SmtpClient client = new SmtpClient(SystemConfig.SmtpServer, SystemConfig.SmtpPort);
            client.Credentials = new System.Net.NetworkCredential(SystemConfig.SenderUserId, SystemConfig.SenderPassword);
            client.EnableSsl = SystemConfig.EnableSSL;
            client.Send(mail);
        }
    }

// <summary>
    /**//// Stores system config / paramerter / hardcoded values
    /// </summary>
    public sealed class SystemConfig
    {       

        public static string SmtpServer
        {
            get
            {
                return ConfigurationManager.AppSettings["smtpServer"];
            }
        }

        public static int SmtpPort
        {
            get
            {
                return int.Parse(ConfigurationManager.AppSettings["smtpPort"]);
            }
        }

        public static string SenderEmail
        {
            get
            {
                return ConfigurationManager.AppSettings["senderEmail"];
            }
        }

        public static string SenderUserId
        {
            get
            {
                return ConfigurationManager.AppSettings["senderUserId"];
            }
        }

        public static string SenderPassword
        {
            get
            {
                return ConfigurationManager.AppSettings["senderPassword"];
            }
        }

        public static bool EnableSSL
        {
            get
            {
                return bool.Parse(ConfigurationManager.AppSettings["EnableSSL"]);
            }
        }
    }

web.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <connectionStrings>
        <add name="pbcrm" connectionString="Server=192.168.2.58;Initial Catalog=P;User ID=sa;PassWord=" providerName="System.Data.SqlClient"/>
    </connectionStrings>

    <appSettings>
        <add key="smtpServer" value="smtp.gmail.com"/>
        <add key="smtpPort" value="587"/>
        <add key="senderEmail"  value="rockniu@gmail.com"/>
        <add key="senderUserId" value="rockniu"/>
        <add key="senderPassword" value="******"/>
        <add key ="EnableSSL" value="true"/>
     </appSettings>    
</configuration>

测试代码：

    [TestFixture]
    public class SendMailTest 
    {
        List<string> _sendTo = new List<string>(10);
        List<string> _copyTo = new List<string>(10);

        public SendMailTest()           
        {
            _sendTo.Add("rockniu@gmail.com");
            _sendTo.Add("rockniu@yahoo.cn");
            _copyTo.Add("rockniu@live.com");
            _copyTo.Add("rockniu@hotmail.com");
        }

        [Test]
        public void SendWebMail()
        {
            EmailHelper.SendWebMail(_sendTo, _copyTo, "Rock is coming", "rock123");
        }

        [Test]
        public void SendNetMail()
        {
            EmailHelper.SendNetMail(_sendTo, _copyTo, "Rock is coming", "rock123");
        }      
    }