How to configure email sending in asp.net core for identity library?

Question

In ASP.NET, you configure email for Identity in IdentityConfig.cs in the App_Start folder, as per my own answer here.

ASP.NET Core Identity is now a library. And does not include this IdentityConfig.cs file by default. So how can I configure email sending, say, for Registration confirmation?

Answer 1

You could refer the following steps to send email using SMTP:

1. Create a EmailSender class, and contains the following method:

    public interface IMyEmailSender
    {
        void SendEmail(string email, string subject, string HtmlMessage);
    }
   
    public class MyEmailSender : IMyEmailSender
    {
        public IConfiguration Configuration { get; }
        public MyEmailSender(IConfiguration configuration)
        {
            Configuration = configuration;
        } 
        public void SendEmail(string email, string subject, string HtmlMessage)
        {
            using (MailMessage mm = new MailMessage(Configuration["NetMail:sender"], email))
            {
                mm.Subject = subject;
                string body = HtmlMessage;
                mm.Body = body;
                mm.IsBodyHtml = true;
                SmtpClient smtp = new SmtpClient();
                smtp.Host = Configuration["NetMail:smtpHost"];
                smtp.EnableSsl = true;
                NetworkCredential NetworkCred = new NetworkCredential(Configuration["NetMail:sender"], Configuration["NetMail:senderpassword"]);
                smtp.UseDefaultCredentials = false;
                smtp.Credentials = NetworkCred;
                smtp.Port = 587;
                smtp.Send(mm);
            }
        } 
    }
   

2. Store the SMTP configuration information in the appsettings.json

   "NetMail": { "smtpHost": "smtp.live.com", "sender": "sender email", "senderpassword": "Password" },

3. Register the EmailSernder in the ConfigureServices method in Startup.cs file.

        services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)
            .AddEntityFrameworkStores<ApplicationDbContext>();
   
        services.AddTransient<IMyEmailSender, MyEmailSender>();
   

4. In the Register.cs file, after creating user, you could use UserManager to get the EmailConfirmationToken, and get the callbackurl, then, call the SendEmail() method to send email.

            var user = new IdentityUser { UserName = Input.Email, Email = Input.Email };
            var result = await _userManager.CreateAsync(user, Input.Password);
            if (result.Succeeded)
            {
                _logger.LogInformation("User created a new account with password.");
   
                var code = await _userManager.GenerateEmailConfirmationTokenAsync(user);
                code = WebEncoders.Base64UrlEncode(Encoding.UTF8.GetBytes(code));
                var callbackUrl = Url.Page(
                    "/Account/ConfirmEmail",
                    pageHandler: null,
                    values: new { area = "Identity", userId = user.Id, code = code, returnUrl = returnUrl },
                    protocol: Request.Scheme);
   
                    _myEmailSender.SendEmail(Input.Email, "Confirm your Email", 
                    $"Please confirm your account by <a href='{HtmlEncoder.Default.Encode(callbackUrl)}'>clicking here</a>.");
   

After that, you will receive a email like this:

After clicking the link, it will redirect to the Confirm Email page, then, check the database, the EmailConfirmed was changed to True .

Reference: Account confirmation and password recovery in ASP.NET Core

Answer 2

As per https://medium.com/@MisterKevin_js/enabling-email-verification-in-asp-net-core-identity-ui-2-1-b87f028a97e0

ASP.NET Core 2 relies a lot on dependency injection. Identity Library's RegisterModel (as well as the other email-dependant models) has the following field:

private readonly IEmailSender _emailSender;

All you have to do is use Startup.cs ConfigureServices method to inject an IEmailSender implemented by yourself:

public void ConfigureServices(IServiceCollection services)
    {
        ...

        services.AddTransient<IEmailSender, EmailSender>();
    }

You may define this EmailSender class inside a folder named Services in your project:

And a possible implementation would be:

using Microsoft.AspNetCore.Identity.UI.Services;
using System.Net;
using System.Net.Mail;
using System.Threading.Tasks;

namespace YourProject.Services
{
    public class EmailSender : IEmailSender
    {
        public Task SendEmailAsync(string email, string subject, string htmlMessage)
        {
            SmtpClient client = new SmtpClient
            {
                Port = 587,
                Host = "smtp.gmail.com", //or another email sender provider
                EnableSsl = true,
                DeliveryMethod = SmtpDeliveryMethod.Network,
                UseDefaultCredentials = false,
                Credentials = new NetworkCredential("your email sender", "password")
            };

            return client.SendMailAsync("your email sender", email, subject, htmlMessage);
        }
    }
}