I'm testing a payment provider (SagePay) and as part of a process, their server POSTs to my site and expects a response. I can't get this to work using MVC.

I set up a classic asp test reponse page and added it to my MVC app:

```
<%
Response.Buffer = True 
response.Clear()
response.contenttype="text/plain"
response.write "Status=OK" & vbCRLF
response.write "RedirectURL=http://www.redirectsomewhere.co.uk" & vbCRLF
response.End()
%>

```

This work fine.

However, when I try to do the same with MVC, it doesn't work:

Controller:

```
[HttpPost]
public ActionResult TestCallback()
{
     return View();
}

```

View:

```
@{
    Response.Buffer = true;
    Response.Clear();
    Response.ContentType = "text/plain";
    Response.Write("Status=OK" + System.Environment.NewLine);
    Response.Write("RedirectURL=http://www.redirectsomewhere.co.uk" + System.Environment.NewLine);
    Response.End();
}

```

The error message is a generic error from the payment provider so is no real help, but I have narrowed the error down to the point at which the page renders.

I can browse to both pages fine (i need remove the HttpPost attribute from the MVC controller method for this), and both pages display identical data.

This is the MVC url that the payment provider is POSTing to:

```
http://myipaddress/CA_UAT/Token/TestCallback

```

This is the classic asp URL that works fine:

```
http://myipaddress/CA_UAT/Token/TestCallback.asp

```

I created a 'Token' directory for the asp page so the urls would match for testing purposes.

What am I doing wrong?

**UPDATE**

In response to Hari's comment, I installed a Firefox plugin called 'Header Spy' which gives me this information:

```
Response HTTP/1.1 200 OK
Source: Response
HttpHeader:Server
Request:User-Agent Cookie
Response:Response Date Set-Cookie

```

Both pages show the same info.