public class EmailHelp{/// <summary>/// Smtp服务器地址/// </summary>private static readonly string SmtpServer = ConfigurationManager.AppSettings["SmtpServer"];/// <summary>/// Pop服务器地址/// </summary>private static readonly string PopServer = ConfigurationManager.AppSettings["PopServer"];/// <summary>/// Imap服务器地址/// </summary>private static readonly string ImapServer = ConfigurationManager.AppSettings["ImapServer"];/// <summary>/// SMTP端口/// </summary>private static readonly int SmtpPort = int.Parse(ConfigurationManager.AppSettings["SmtpPort"]);/// <summary>/// POP端口/// </summary>private static readonly int PopPort = int.Parse(ConfigurationManager.AppSettings["PopPort"]);/// <summary>/// IMAP端口/// </summary>private static readonly int ImapPort = int.Parse(ConfigurationManager.AppSettings["ImapPort"]);/// <summary>/// 邮件发送/// </summary>/// <param name="mailFromAccount">发送邮箱账号</param>/// <param name="mailPassword">发送邮箱密码</param>/// <param name="message">邮件</param>public static void SendEmali(string mailFromAccount, string mailPassword, MimeMessage message){using (var client = new MailKit.Net.Smtp.SmtpClient()){client.Connect(SmtpServer, SmtpPort, false);// Note: since we don't have an OAuth2 token, disable// the XOAUTH2 authentication mechanism.client.AuthenticationMechanisms.Remove("XOAUTH2");// Note: only needed if the SMTP server requires authentication
                client.Authenticate(mailFromAccount, mailPassword);client.Send(message);client.Disconnect(true);}}/// <summary>/// 创建文本消息/// </summary>/// <param name="fromAddress">发件地址</param>/// <param name="toAddressList">收件地址</param>/// <param name="title">标题</param>/// <param name="content">内容</param>/// <param name="IsPostFiles">是否将POST上传文件加为附件</param>/// <returns></returns>public static MimeMessage CreateTextMessage(MailboxAddress fromAddress, IList<MailboxAddress> toAddressList, string title, string content, bool IsPostFiles = false){var message = new MimeMessage();message.From.Add(fromAddress);message.To.AddRange(toAddressList);message.Subject = title; //设置消息的主题var html = new TextPart("html"){Text = content,};var alternative = new Multipart("alternative");alternative.Add(html);var multipart = new Multipart("mixed");multipart.Add(alternative);if (IsPostFiles){IList<MimePart> multiPartList = GetMimePartList();foreach (var item in multiPartList){multipart.Add(item);}}message.Body = multipart;return message;}/// <summary>/// 收邮件/// </summary>/// <param name="mailFromAccount">发送邮箱账号</param>/// <param name="mailPassword">发送邮箱密码</param>/// <param name="searchQuery">查询条件</param>/// <param name="folderName">文件夹名称</param>/// <returns></returns>public static IList<IMessageSummary> ReceiveEmail(string mailFromAccount, string mailPassword, string folderName, SearchQuery searchQuery = null){//打开收件箱var folder = OpenFolder(mailFromAccount, mailPassword, folderName);//IList<OrderBy> orderByList = new List<OrderBy> { OrderBy.Date };//查询所有的邮件var uidss = folder.Search(searchQuery);IList<IMessageSummary> msgList = new List<IMessageSummary>();if (uidss.Count > 0)//判断是否查询到邮件
            {//获取邮件头msgList = folder.Fetch(uidss, MessageSummaryItems.UniqueId | MessageSummaryItems.Full);}folder.Close();return msgList;}/// <summary>/// 根据唯一号查询信件/// </summary>/// <param name="mailFromAccount">邮箱账号</param>/// <param name="mailPassword">邮箱密码</param>/// <param name="id">唯一号</param>/// <param name="folderName">文件夹名称</param>/// <returns></returns>public static MimeMessage GetEmailByUniqueId(string mailFromAccount, string mailPassword, uint id, string folderName){//打开收件箱var folder = OpenFolder(mailFromAccount, mailPassword, folderName);UniqueId emailUniqueId = new UniqueId(id);MimeMessage message = folder.GetMessage(emailUniqueId);/*将邮件设为已读*/MessageFlags flags = MessageFlags.Seen;folder.SetFlags(emailUniqueId, flags, true);return message;}/// <summary>/// 读取上传的文件/// </summary>/// <returns></returns>public static IList<MimePart> GetMimePartList(){IList<MimePart> mimePartList = new List<MimePart>();var current = HttpContext.Current;if (current != null){HttpRequest request = current.Request;HttpFileCollection files = request.Files;int filesCount = files.Count;for (int i = 0; i < filesCount; i++){HttpPostedFile item = files[i];MimePart attachment = new MimePart(item.ContentType){ContentObject = new ContentObject(item.InputStream, ContentEncoding.Default),ContentDisposition = new ContentDisposition(ContentDisposition.Attachment),ContentTransferEncoding = ContentEncoding.Base64,FileName = item.FileName};mimePartList.Add(attachment);}}return mimePartList;}/// <summary>/// 打开邮箱文件夹/// </summary>/// <param name="mailFromAccount">邮箱账号</param>/// <param name="mailPassword">邮箱密码</param>/// <param name="folderName">文件夹名称(INBOX:收件箱名称)</param>/// <returns></returns>public static IMailFolder OpenFolder(string mailFromAccount, string mailPassword, string folderName){ImapClient client = new ImapClient();client.Connect(ImapServer, ImapPort);client.Authenticate(mailFromAccount, mailPassword);//获取所有文件夹//List<IMailFolder> mailFolderList = client.GetFolders(client.PersonalNamespaces[0]).ToList();var folder = client.GetFolder(folderName);//打开文件夹并设置为读的方式
            folder.Open(MailKit.FolderAccess.ReadWrite);return folder;}/// <summary>/// 下载邮件附件/// </summary>/// <param name="mimePart"></param>public static void DownFile(MimePart mimePart){HttpContext context = HttpContext.Current;// 设置编码和附件格式context.Response.ContentType = mimePart.ContentType.ToString();//context.Response.ContentEncoding = Encoding.UTF8;
context.Response.Charset = "";string fileName = HttpUtility.UrlEncode(mimePart.FileName, Encoding.UTF8);context.Response.AppendHeader("Content-Disposition","attachment;filename=" + fileName);using (MemoryStream ms = new MemoryStream()){mimePart.ContentObject.DecodeTo(ms);ms.Flush();ms.Position = 0;context.Response.BinaryWrite(ms.GetBuffer());context.Response.End();}}}