raven/server/AyaNova/util/Mailer.cs

using MailKit.Net.Smtp;
using MimeKit;
using System;
using System.Threading.Tasks;
using MimeKit.Text;
using System.IO;

namespace AyaNova.Util
{
    public interface IMailer
    {
        Task SendEmailAsync(string email, string subject, string body, AyaNova.Models.GlobalOpsNotificationSettings smtpSettings, string attachPDF = null);
    }

    public class Mailer : IMailer
    {
        public Mailer()
        {

        }

        public async Task SendEmailAsync(string email, string subject, string body, AyaNova.Models.GlobalOpsNotificationSettings smtpSettings, string attachPDFPath = null)
        {
            try
            {
                var message = new MimeMessage();
                message.From.Add(new MailboxAddress(smtpSettings.NotifyFromAddress, smtpSettings.NotifyFromAddress));
                message.To.Add(MailboxAddress.Parse(email));
                message.Subject = subject;

                if (!string.IsNullOrWhiteSpace(attachPDFPath))
                {                    
                    var attachment = new MimePart("application/pdf", "pdf")
                    {
                        Content = new MimeContent(File.OpenRead(attachPDFPath), ContentEncoding.Default),
                        ContentDisposition = new ContentDisposition(ContentDisposition.Attachment),
                        ContentTransferEncoding = ContentEncoding.Base64,
                        FileName = Path.GetFileName("test.pdf")
                        //FileName = Path.GetFileName(attachPDFPath)

                    };
                    
                    var multipart = new Multipart("mixed");
                    if (!string.IsNullOrWhiteSpace(body))
                        multipart.Add(new TextPart(TextFormat.Plain) { Text = body });
                    multipart.Add(attachment);
                    message.Body = multipart;
                }
                else
                {
                    if (!string.IsNullOrWhiteSpace(body))
                        message.Body = new TextPart(TextFormat.Plain) { Text = body };
                }

                using (var client = new SmtpClient())
                {
                    client.ServerCertificateValidationCallback = (s, c, h, e) => true;

                    bool UseSSL = smtpSettings.ConnectionSecurity != Biz.NotifyMailSecurity.None;
                    await client.ConnectAsync(smtpSettings.SmtpServerAddress, smtpSettings.SmtpServerPort, UseSSL);


                    await client.AuthenticateAsync(smtpSettings.SmtpAccount, smtpSettings.SmtpPassword);
                    await client.SendAsync(message);
                    await client.DisconnectAsync(true);
                }
            }
            catch (Exception e)
            {
                throw new InvalidOperationException(e.Message);
            }
        }
    }
}