var key = new ApiKeyConnection("SG.api.key"); var client = new SendGridClient(key); client.MailClient.SendAsync(new Email { Personalizations = new List<Personalization> { new Personalization { To = new List<EmailDetail> { new EmailDetail { Email = "customer@yahoooooo.com", Name = "Customer Name" } } } }, From = new EmailDetail { Email = "no-reply@company.domain", Name = "Company Letter" }, Subject = "sup", Content = new List<Content> { new Content { Type = "text/html", Value = "<h1>yo yo! :)</h1>" } } }).Wait();