ASP.NET Core - Error handling send email and present error page

I have the following code in my startup.cs to email any errors in the application:

app.UseExceptionHandler(
    options =>
    {
        //options.UseDeveloperExceptionPage();
        options.Run(
            async context =>
            {
                var ex = context.Features.Get<IExceptionHandlerFeature>();
                if (ex != null)
                {
                    var err = $"<h1>Error: {ex.Error.Message}</h1>{ex.Error.Source}<hr />{context.Request.Path}<br />";
                    err += $"QueryString: {context.Request.QueryString}<hr />";

                    err += $"Stack Trace<hr />{ex.Error.StackTrace.Replace(Environment.NewLine, "<br />")}";
                    if (ex.Error.InnerException != null)
                        err +=
                            $"Inner Exception<hr />{ex.Error.InnerException?.Message.Replace(Environment.NewLine, "<br />")}";

                    if (context.Request.Form.Any())
                    {
                        err += "<table border=\"1\"><tr><td colspan=\"2\">Form collection:</td></tr>";
                        foreach (var form in context.Request.Form)
                        {
                            err += $"<tr><td>{form.Key}</td><td>{form.Value}</td></tr>";
                        }
                        err += "</table>";
                    }

                    await msg.SendEmailAsync(appSettings.Value.ErrorDeliveryEmailAddress, "CMP v2 error",
                        err);
                    context.Response.Redirect("/Home/Error?r=" +
                                                System.Net.WebUtility.UrlEncode(context.Request.Path + "?" +
                                                                                context.Request.QueryString));
                }
            });
        //options.UseExceptionHandler("/Home/Error");
        //options.UseStatusCodePagesWithReExecute("/Home/Error/{0}");
    }
);

However, it does pick up 404 errors.

How can I use the:

app.UseExceptionHandler("/Home/Error");
app.UseStatusCodePagesWithReExecute("/Home/Error/{0}");

Code, and still email the error details to a support queue?