WebApi for Email delivery - asp.net-mvc-4

Question

I created a Web API controller inside my ASP.NET MVC 4 Website to specifically send emails so that I can consume it for this purpose and eventually provide it to other consumers (Mobile, etc).
Everything is working fine but I want to use it asynchronously, altough it's not working that way, my website blocks until the work is finished.
I have a regular Controller where I call a helper class that calls the API.
Controller Code :
[HttpPost]
public async Task<ActionResult> ContactUs(ContactUsModel model)
{
ExternalApiCalls extApi = new ExternalApiCalls();
await extApi.PostContactUs(model).ConfigureAwait(false);
return RedirectToAction("ContactUsSuccess", "Account");
}
Helper Class Code :
public class ExternalApiCalls
{
public HttpClient client { get; set; }
public ExternalApiCalls()
{
client = new HttpClient();
client.BaseAddress = new Uri("http://localhost:10239/");
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
}
public async Task PostContactUs(ContactUsModel model)
{
try
{
var response = await client.PostAsJsonAsync("api/WAPIMail", model).ConfigureAwait(false);
}
catch (HttpRequestException ex)
{
}
catch (System.FormatException)
{
}
finally
{
}
}
}
Web API Controller :
public class WAPIMailController : ApiController
{
public void PostContactUs(ContactUsModel model)
{
// Send Email Here
}
}
Thanks a lot for your help

Answer 1

I finally managed how to do it..
For brevity's sake, I am showing oversimplified code, see below:
Controller :
[HttpPost]
public ActionResult ContactUs(ContactUsModel model)
{
new ExternalApiCalls().MailContactUs(model);
return RedirectToAction("ContactUsSuccess", "Account");
}
Helper Class :
public void MailContactUs(ContactUsModel model)
{
client.PostAsJsonAsync("api/WAPIMail/MailContactUs", model).ConfigureAwait(false);
}
Web API Controller :
[HttpPost]
public void MailContactUs(ContactUsModel model)
{
//Email Logic Here
}