C#郵件發送幫助類

1.新建一個抽象類FTMailBase.cs,代碼如下：

/* ========================================================		
 * Module Name: JuCheap.Service.SendEmail
 * Class  Name: FTMailBase
 * Description: 所有郵件Sender的基類
 * Company    : JuCheap
 * Author     : JuCheap
 * Create Date: 2014-11-03
===========================================================*/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Mail;
using System.Configuration;
using JuCheap.Common.Extention;

namespace JuCheap.Service.SendEmail
{
    /// <summary>
    /// 所有郵件Sender的基類
    /// </summary>
    public abstract class FTMailBase
    {
        /// <summary>
        /// 發件人
        /// </summary>
        public string From { get; set; }
        /// <summary>
        /// 收件人
        /// </summary>
        public string To { get; set; }
        /// <summary>
        /// 主題
        /// </summary>
        public string Subject { get; set; }
        //正文
        public string Body { get; set; }
        /// <summary>
        /// 抄送
        /// </summary>
        public string CC { get; set; }
        /// <summary>
        /// 顯示名稱
        /// </summary>
        public string DisplayName { get; set; }
        /// <summary>
        /// 發送郵件
        /// </summary>
        /// <param name="smtpServer">郵件服務器地址</param>
        /// <param name="port">端口</param>
        /// <param name="userName">帳號</param>
        /// <param name="password">密碼</param>
        /// <param name="enableSSL">是否啓用SSL</param>
        /// <returns></returns>
        public abstract bool Send(string smtpServer = null
                         , int? port = default(int?)
                         , string userName = null
                         , string password = null
                         , bool? enableSSL = default(bool?));

        /// <summary>
        /// 工廠方法，獲取郵件SENDER實例
        /// </summary>
        public static FTMailBase Instance
        {
            get
            {
                return new SMTPMailer();
            }
        }
    }
}

2.實現抽象類;新建郵件發送類：SMTPMailer.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Mail;
using System.Configuration;
using JuCheap.Common.Extention;

namespace JuCheap.Service.SendEmail
{
    internal class SMTPMailer : FTMailBase
    {
        /// <summary>
        /// SMTP郵件Sender的類的封裝
        /// </summary>
        /// <param name="smtpServer">smtp服務地址</param>
        /// <param name="port">端口號</param>
        /// <param name="userName">用戶名</param>
        /// <param name="password">密碼</param>
        /// <param name="enableSSL">是否採用ssl的方式</param>
        public override bool Send(string smtpServer = null, int? port = default(int?), string userName = null, string password = null,bool? enableSSL=default(bool?))
        {
            bool isSended = false;
            try
            {
                smtpServer = smtpServer.IsBlank() ? ConfigurationManager.AppSettings["SMTPServer_Address"] : smtpServer;
                port = !port.HasValue ? Convert.ToInt32(ConfigurationManager.AppSettings["SMTPServer_Port"]) : port.Value;
                userName = userName.IsBlank() ? ConfigurationManager.AppSettings["SMTPServer_UserName"] : userName;
                password = password.IsBlank() ? ConfigurationManager.AppSettings["SMTPServer_UserPwd"] : password;

                if (!enableSSL.HasValue)
                {
                    bool temp = false;
                    bool.TryParse(ConfigurationManager.AppSettings["SMTPServer_EnableSSL"], out temp);
                    enableSSL = temp;
                }

                System.Net.Mail.MailMessage message = new System.Net.Mail.MailMessage();
                message.To.Add(this.To);
                message.Sender = new MailAddress(userName, userName);
                if (!this.CC.IsBlank())
                    message.CC.Add(this.CC);
                message.Subject = System.Text.UTF8Encoding.Default.GetString(System.Text.UTF8Encoding.Default.GetBytes(this.Subject));
                
                if (DisplayName.IsBlank())
                    message.From = new System.Net.Mail.MailAddress(this.From);
                else
                    message.From = new System.Net.Mail.MailAddress(this.From, System.Text.UTF8Encoding.Default.GetString(System.Text.UTF8Encoding.Default.GetBytes(this.DisplayName)));

                message.Body = System.Text.UTF8Encoding.Default.GetString(System.Text.UTF8Encoding.Default.GetBytes(this.Body));
                message.BodyEncoding = Encoding.GetEncoding("GBK") ;
                message.HeadersEncoding = Encoding.UTF8;
                message.SubjectEncoding = Encoding.UTF8;
                message.IsBodyHtml = true;
                message.DeliveryNotificationOptions = DeliveryNotificationOptions.OnFailure;
                message.ReplyToList.Add(new MailAddress(this.From));
                
                System.Net.Mail.SmtpClient smtp = new System.Net.Mail.SmtpClient(smtpServer, port.Value);
                smtp.DeliveryMethod = SmtpDeliveryMethod.Network;

                smtp.UseDefaultCredentials = false;
                smtp.Credentials = new NetworkCredential(userName, password);
                smtp.Timeout = 30000;

                smtp.EnableSsl = enableSSL.Value;

                smtp.SendCompleted += new SendCompletedEventHandler(smtp_SendCompleted);
                smtp.Send(message);
                isSended = true;
            }
            catch (Exception ex)
            {
                Log.Write(ex);
                throw ex;
            }
            return isSended;
        }

        /// <summary>
        /// 編碼成64位
        /// </summary>
        /// <param name="s">需要編碼的內容</param>
        /// <returns>返回被編碼的內容</returns>
        private string encodebase64(string s)
        {
            string encode = "";
            byte[] bytes = Encoding.UTF8.GetBytes(s);
            try
            {
                encode = Convert.ToBase64String(bytes);
            }
            catch
            {
                encode = s;
            }
            return encode;
        }
        /// <summary>
        /// 發送完成後，如果有錯誤，記錄日誌
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void smtp_SendCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
        {
            if (e.Error != null)
            {
                Log.Write(e.Error);
            }
        }
    }
}