Inboxintel/src/InboxIntel.Infrastructure/Notifications/SmtpEmailSender.cs

using InboxIntel.Application.Abstractions;
using InboxIntel.Infrastructure.Configuration;
using MailKit.Net.Smtp;
using MailKit.Security;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using MimeKit;

namespace InboxIntel.Infrastructure.Notifications;

public class SmtpEmailSender : IEmailSender
{
    private readonly SmtpOptions _options;
    private readonly ILogger<SmtpEmailSender> _logger;

    public SmtpEmailSender(IOptions<SmtpOptions> options, ILogger<SmtpEmailSender> logger)
    {
        _options = options.Value;
        _logger = logger;
    }

    public bool IsEnabled => _options.Enabled && !string.IsNullOrWhiteSpace(_options.Host);

    public async Task SendAsync(string toAddress, string subject, string htmlBody, CancellationToken ct = default)
    {
        if (!IsEnabled)
        {
            _logger.LogDebug("SMTP not configured; skipping email \"{Subject}\" to {To}", subject, toAddress);
            return;
        }

        var message = new MimeMessage();
        message.From.Add(new MailboxAddress(_options.FromName, _options.FromAddress));
        message.To.Add(MailboxAddress.Parse(toAddress));
        message.Subject = subject;
        message.Body = new BodyBuilder { HtmlBody = htmlBody }.ToMessageBody();

        using var client = new SmtpClient();
        var socketOptions = _options.UseSsl ? SecureSocketOptions.StartTls : SecureSocketOptions.None;
        await client.ConnectAsync(_options.Host, _options.Port, socketOptions, ct);
        if (!string.IsNullOrEmpty(_options.User))
            await client.AuthenticateAsync(_options.User, _options.Password, ct);
        await client.SendAsync(message, ct);
        await client.DisconnectAsync(true, ct);
    }
}