// ... Usings
using Microsoft.AspNetCore.Identity.UI.Services;
using MailSenderApp.Services;

namespace MailSenderApp {
    public class Startup {

        // ... Startup initializer and other methods

        public void ConfigureServices(IServiceCollection services)
        {
            // ... Other services
            services.AddDefaultIdentity<IdentityUser>().AddEntityFrameworkStores<ApplicationDbContext>();

            services.AddTransient<IEmailSender, EmailSender>(i =>
                new EmailSender(
                    Configuration["EmailSender:Host"],
                    Configuration.GetValue<int>("EmailSender:Port"),
                    Configuration.GetValue<bool>("EmailSender:EnableSSL"),
                    Configuration["EmailSender:UserName"],
                    Configuration["EmailSender:Password"]
                )
            );

            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
        }
    }
}