Haven't a clue with ASP (just to make that clear!)

Hi all
Sorry to come to your forums with absolutely no prior knowledge of ASP.net!
Basically, I'm a PHP developer, and our web server here in work is a Windows Web Server 2008 machine with IIS 7. Being a PHP developer, naturally I only ever deal with PHP. We've taken on a client who simply wants to migrate his web site from their previous hosts to us, which we've done and all is well, apart from one thing, their 'Enqury' script. When we tested sending an enquiry through the web site, we get 'Error 500'. This is the same when we run it straight from the server. The files content is below.
<%@Language=VBScript %> <% mailto = "removed@email.address" copyto = "removed@email.address" strFrom = "removed@email.address" strRedirectURL = "thankyou.html" subject = "Website Info Request" Dim MyCDONTSMail2 Dim HTML Set MyCDONTSMail2 = CreateObject("CDONTS.NewMail") HTML = "<!DOCTYPE HTML PUBLIC""-//IETF//DTD HTML//EN ...