example.cs

using Mailjet.Client;
using Mailjet.Client.Resources;
using System;
using Newtonsoft.Json.Linq;

namespace Mailjet.ConsoleApplication
{
   class Program
   {
      /// <summary>
      /// This calls sends an email to one recipient.
      /// </summary>
      static void Main(string[] args)
      {
         RunAsync().Wait();
      }
      static async Task RunAsync()
      {
         MailjetClient client = new       MailjetClient(Environment.GetEnvironmentVariable("MJ_APIKEY_PUBLIC"), Environment.GetEnvironmentVariable("MJ_APIKEY_PRIVATE"));
         MailjetRequest request = new MailjetRequest
         {
            Resource = Send.Resource,
         }
            .Property(Send.FromEmail, "pilot@mailjet.com")
            .Property(Send.FromName, "Mailjet Pilot")
            .Property(Send.Subject, "Your email flight plan!")
            .Property(Send.TextPart, "Dear passenger, welcome to Mailjet! May the delivery force be with you!")
            .Property(Send.HtmlPart, "<h3>Dear passenger, welcome to Mailjet!</h3><br />May the delivery force be with you!")
            .Property(Send.Recipients, new JArray {
                new JObject {
                 {"Email", "passenger@mailjet.com"}
                 }
                });
         MailjetResponse response = await client.PostAsync(request);
         if (response.IsSuccessStatusCode)
         {
            Console.WriteLine(string.Format("Total: {0}, Count: {1}\n", response.GetTotal(), response.GetCount()));
            Console.WriteLine(response.GetData());
         }
         else
         {
            Console.WriteLine(string.Format("StatusCode: {0}\n", response.StatusCode));
            Console.WriteLine(string.Format("ErrorInfo: {0}\n", response.GetErrorInfo()));
            Console.WriteLine(string.Format("ErrorMessage: {0}\n", response.GetErrorMessage()));
         }
      }
   }
}