string Body = String.Empty;
string path = Path.Combine(HttpContext.Current.Server.MapPath(@"~/Views/EmailTemplates/"), "Template1.html");
using (StreamReader reader = new StreamReader(path))
{
                Body = reader.ReadToEnd();
}

Body = Body.Replace("{subject}", subject);
Body = Body.Replace("{message}", messageText);
Body = Body.Replace("{costam}", costam);