How can I pass email id to action method as parameter using @Html.ActionLink?

Index.chtml page itself i have this link

@Html.ActionLink("Edit","EditUserProfile",new {vchUserID = item.vchUserID})

Inside user Controller itself

// GET: /User/ViewUserProfile/1
public ActionResult EditUserProfile(string userID = "abdul@kareems.com")
{
    LIVE_USER objUserFind = db.LIVE_USER.Find(userID);

    if (objUserFind == null)
    {
        return HttpNotFound();
    }

    return View(objUserFind);

}

//
//POST: /Admin/EditAdminProfile/1
[HttpPost]
public ActionResult EditUserProfile(LIVE_USER objUserFind)
{
    if (ModelState.IsValid)
    {
        db.Entry(objUserFind).State = EntityState.Modified;
        db.SaveChanges();
        return RedirectToAction("Index");
    }
    return View(objUserFind);
}

RouteConfig.cs file itself i have url structure like bellow.

public static void RegisterRoutes(RouteCollection routes)
{
    routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
    routes.MapRoute(
            name: "Default",
            url: "{controller}/{action}/{vchUserID}",
            defaults: new { controller = "Admin", action = "Index", vchUserID = UrlParameter.Optional /*kareem removed vchUserID = UrlParameter.Optional*/         }
        );

Result i got is: *HTTP Error 404.0 - Not Found The resource you are looking for has been removed, had its name changed, or is temporarily unavailable.*