rm-ventas/services-externos/src/ServicesExternos.API/Services/EmailService.cs

using MailKit.Net.Smtp;
using MailKit.Security;
using MimeKit;
using ServicesExternos.API.Models;

namespace ServicesExternos.API.Services;

public class EmailService
{
    private readonly string _smtpHost;
    private readonly int _smtpPort;
    private readonly string _smtpUser;
    private readonly string _smtpPassword;

    public EmailService(IConfiguration configuration)
    {
        _smtpHost = configuration["Email:Host"] ?? "smtp.gmail.com";
        _smtpPort = int.Parse(configuration["Email:Port"] ?? "587");
        _smtpUser = configuration["Email:User"] ?? "noresponder@norteamericano.cl";
        _smtpPassword = configuration["Email:Password"] ?? "";
    }

    public async Task<string> SendAsync(EmailRequest request)
    {
        try
        {
            var message = new MimeMessage();
            message.From.Add(new MailboxAddress("Norteamericano", _smtpUser));
            message.To.Add(new MailboxAddress("", request.To));
            message.Subject = request.Subject;

            var body = new TextPart(request.IsHtml ? "html" : "plain")
            {
                Text = request.Body
            };

            if (request.AttachmentPaths != null && request.AttachmentPaths.Count > 0)
            {
                var multipart = new Multipart("mixed") { body };
                foreach (var path in request.AttachmentPaths)
                {
                    if (File.Exists(path))
                        multipart.Add(new MimePart("application", "pdf")
                        {
                            Content = new MimeContent(File.OpenRead(path), ContentEncoding.Default),
                            ContentDisposition = new ContentDisposition(ContentDisposition.Attachment),
                            FileName = Path.GetFileName(path)
                        });
                }
                message.Body = multipart;
            }
            else
            {
                message.Body = body;
            }

            using var client = new SmtpClient();
            await client.ConnectAsync(_smtpHost, _smtpPort, SecureSocketOptions.StartTls);
            await client.AuthenticateAsync(_smtpUser, _smtpPassword);
            await client.SendAsync(message);
            await client.DisconnectAsync(true);

            return "ok";
        }
        catch (Exception ex)
        {
            return $"Error: {ex.Message}";
        }
    }
}