Extract Email Attachment

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.Net;

namespace PDFcoApiExample
{
    class Program
  {
    // The authentication key (API Key).
    // Get your own by registering at https://app.pdf.co
    const String API_KEY = "***********************************";

    // Direct URL of source PDF file.
    const string SourceFileUrl = "https://bytescout-com.s3-us-west-2.amazonaws.com/files/demo-files/cloud-api/pdf-info/sample.pdf";

    // Email Details

    const string From = "John Doe <john@example.com>";
    const string To = "Partner <partner@example.com>";
    const string Subject = "Check attached sample pdf";
    const string BodyText = "Please check the attached pdf";
    const string BodyHtml = "Please check the attached pdf";
    const string SmtpServer = "smtp.gmail.com";
    const string SmtpPort = "587";
    const string SmtpUserName = "my@gmail.com";
    const string SmtpPassword = "app specific password created as https://support.google.com/accounts/answer/185833";

    static void Main(string[] args)
    {
      // Create standard .NET web client instance
      WebClient webClient = new WebClient();

      // Set API Key
      webClient.Headers.Add("x-api-key", API_KEY);

      // URL for `Email Send` API call
      string url = "https://api.pdf.co/v1/email/send";

      // Prepare requests params as JSON
      Dictionary<string, object> parameters = new Dictionary<string, object>();
      parameters.Add("url", SourceFileUrl);

      parameters.Add("from", From);
      parameters.Add("to", To);
      parameters.Add("subject", Subject);
      parameters.Add("bodytext", BodyText);
      parameters.Add("bodyHtml", BodyHtml);
      parameters.Add("smtpserver", SmtpServer);
      parameters.Add("smtpport", SmtpPort);
      parameters.Add("smtpusername", SmtpUserName);
      parameters.Add("smtppassword", SmtpPassword);

      // Convert dictionary of params to JSON
      string jsonPayload = JsonConvert.SerializeObject(parameters);

      try
      {
        // Execute POST request with JSON payload
        string response = webClient.UploadString(url, jsonPayload);

        // Parse JSON response
        JObject json = JObject.Parse(response);

        if (json["error"].ToObject<bool>() == false)
        {
          Console.WriteLine("Email Sent Successfully!");
        }
        else
        {
          Console.WriteLine(json["message"].ToString());
        }
      }
      catch (WebException e)
      {
        Console.WriteLine(e.ToString());
      }

      webClient.Dispose();

      Console.WriteLine();
      Console.WriteLine("Press any key...");
      Console.ReadKey();
    }
  }
}