RetryClient

EmailService.cs

            RestClient client = new RestClient();
            RestRequest request = new RestRequest();
            request.AddParameter("domain", domain, ParameterType.UrlSegment);
            request.Resource = "{domain}/messages";
            request.AddParameter("from", sender);
            request.AddParameter("to", sendTo);
            request.AddParameter("subject", "...");
            request.AddParameter("text", "...");
            request.Method = Method.POST;

            var response = backoffStrategy.RetryOnOperationResult(attempt => client.Execute(request), 50,
                tempResponse => tempResponse.StatusCode != HttpStatusCode.Accepted && tempResponse.StatusCode != HttpStatusCode.OK);