サーバーからの電子メール添付ファイルの取得

Question

Excel添付ファイルを含む電子メールが定期的に送信されます（要求はユーザー主導です）。目標は、添付ファイルを電子メールから自動的に抽出し、ファイル内のデータを処理するメソッドに渡すことです。

私はサードパーティのツールやライブラリから遠ざかっていきたいと思います。できるだけ簡単で最小限のチェックと機能を維持したいと思います。文字通りメールをダウンロードして添付ファイルを保存してください。メールアドレス既知のソース（スパムをブロックする）と一致します。

リサーチからは、3つの解決策があります。どちらが最も賢明なルートですか？他にもオプションがありますか？誰も私に関連する（そして最近の）チュートリアルを教えてもらえますか？

はおそらく（C＃の、VS2010を使用して）取引EWS（優先オプション）を使用して、自分自身の機能を書くサードパーティのPOPクライアントを使用して

• ダウンロード
• むしろOutlookがそれをダウンロードし、その後から添付ファイルを抽出していOutlook

Answer 1

public class KCSExchangeLink : IKCSExchangeLink 
{ 

    private bool CertificateValidationCallBack(
     object sender, 
     System.Security.Cryptography.X509Certificates.X509Certificate certificate, 
     System.Security.Cryptography.X509Certificates.X509Chain chain, 
     System.Net.Security.SslPolicyErrors sslPolicyErrors) 
    { 
     // If the certificate is a valid, signed certificate, return true. 
     if (sslPolicyErrors == System.Net.Security.SslPolicyErrors.None) 
     { 
      return true; 
     } 

     // If there are errors in the certificate chain, look at each error to determine the cause. 
     if ((sslPolicyErrors & System.Net.Security.SslPolicyErrors.RemoteCertificateChainErrors) != 0) 
     { 
      if (chain != null && chain.ChainStatus != null) 
      { 
       foreach (System.Security.Cryptography.X509Certificates.X509ChainStatus status in chain.ChainStatus) 
       { 
        if ((certificate.Subject == certificate.Issuer) && 
         (status.Status == System.Security.Cryptography.X509Certificates.X509ChainStatusFlags.UntrustedRoot)) 
        { 
         // Self-signed certificates with an untrusted root are valid. 
         continue; 
        } 
        else 
        { 
         if (status.Status != System.Security.Cryptography.X509Certificates.X509ChainStatusFlags.NoError) 
         { 
          // If there are any other errors in the certificate chain, the certificate is invalid, 
          // so the method returns false. 
          return false; 
         } 
        } 
       } 
      } 

      // When processing reaches this line, the only errors in the certificate chain are 
      // untrusted root errors for self-signed certificates. These certificates are valid 
      // for default Exchange server installations, so return true. 
      return true; 
     } 
     else 
     { 
      // In all other cases, return false. 
      return false; 
     } 
    } 

    private bool RedirectionUrlValidationCallback(string redirectionUrl) 
    { 
     // The default for the validation callback is to reject the URL. 
     bool result = false; 

     Uri redirectionUri = new Uri(redirectionUrl); 

     // Validate the contents of the redirection URL. In this simple validation 
     // callback, the redirection URL is considered valid if it is using HTTPS 
     // to encrypt the authentication credentials. 
     if (redirectionUri.Scheme == "https") 
     { 
      result = true; 
     } 
     return result; 
    } 

    public void SaveAttachment(string email, string password, string downloadfolder, string fromaddress) 
    { 
     ServicePointManager.ServerCertificateValidationCallback = CertificateValidationCallBack; 
     ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2007_SP1); 
     service.Credentials = new WebCredentials(email, password); 
     service.TraceEnabled = true; 
     service.TraceFlags = TraceFlags.All; 
     service.AutodiscoverUrl(email, RedirectionUrlValidationCallback); 

     // Bind the Inbox folder to the service object. 
     Folder inbox = Folder.Bind(service, WellKnownFolderName.Inbox); 

     // The search filter to get unread email. 
     SearchFilter sf = new SearchFilter.SearchFilterCollection(LogicalOperator.And, new SearchFilter.IsEqualTo(EmailMessageSchema.IsRead, false)); 
     ItemView view = new ItemView(1); 

     // Fire the query for the unread items. 
     // This method call results in a FindItem call to EWS. 
     FindItemsResults<Item> findResults = service.FindItems(WellKnownFolderName.Inbox, sf, view); 

     foreach (EmailMessage item in findResults) 
     { 
      item.Load(); 

      /* download attachment if any */ 
      if (item.HasAttachments && item.Attachments[0] is FileAttachment && item.From.Address == fromaddress) 
      { 
       FileAttachment fileAttachment = item.Attachments[0] as FileAttachment; 

       /* download attachment to folder */ 
       fileAttachment.Load(downloadfolder + fileAttachment.Name); 
      } 

      /* mark email as read */ 
      item.IsRead = true; 
      item.Update(ConflictResolutionMode.AlwaysOverwrite); 
     } 

    } 

} 

Answer 2

ここでは、私たちのシステムでどのように行うのですか？私がこれをかなり素早く投稿しなければならないので、あなたが私に何かを説明してもらいたいかどうかを教えてください。

namespace Namespace.Email 
{ 
    public class EmailLinker 
    { 
     ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2013_SP1); 

     public EmailLinker() 
     { 
      service.Credentials = new NetworkCredential("username", "password", "domain"); 
      service.AutodiscoverUrl("email@email.com"); 
     } 

     public void linkEmails() 
     { 
      FindItemsResults<Item> findResults = service.FindItems(WellKnownFolderName.Inbox, new ItemView(128)); 
      if (findResults.TotalCount > 0) 
      { 
       ServiceResponseCollection<GetItemResponse> items = service.BindToItems(findResults.Select(item => item.Id), new PropertySet(BasePropertySet.FirstClassProperties, EmailMessageSchema.From, EmailMessageSchema.ToRecipients)); 

       foreach (GetItemResponse i in items) 
       { 
        MailItem m = new MailItem(); 
        Item it = i.Item; 
        m.From = ((Microsoft.Exchange.WebServices.Data.EmailAddress)it[EmailMessageSchema.From]).Address; 
        m.Recipients = ((Microsoft.Exchange.WebServices.Data.EmailAddressCollection)it[EmailMessageSchema.ToRecipients]).Select(r => r.Address).ToArray(); 
        m.Subject = it.Subject; 
        m.Body = it.Body.Text; 
        m.Recieved = it.DateTimeReceived; 
        m.attachments = it.Attachments; 
        foreach (Attachment a in m.attachments) 
         this.uploadAttachments(a); 
        i.Item.Delete(DeleteMode.HardDelete); 
       } 
      } 
     } 

     private void uploadAttachments(Attachment a) 
     { 
      ContentFile cf = new ContentFile(); 
      cf.Name = a.Name; 
      cf.Size = a.Size; 
      cf.ContentType = MimeTypeMap.GetMimeType(Path.GetExtension(a.Name).Replace(".","")); 
      FileAttachment fa = (FileAttachment)a; 
      fa.Load(); 
      cf.Data = fa.Content; 
      cf.DateAdded = DateTime.Now; 
      cf.save(); 
     } 

     public class MailItem 
     { 
      public int id; 
      public string From; 
      public string[] Recipients; 
      public string Subject; 
      public string Body; 
      public DateTime Recieved; 
      public string RecievedString 
      { 
       get 
       { 
        return Recieved.ToShortDateString() + " " + Recieved.ToShortTimeString(); 
       } 
      } 
      public AttachmentCollection attachments; 
     } 
    } 
}