SmtpClient smtpClient = new SmtpClient();
        Attachment att=new System.Net.Mail.Attachment("Path");
        smtpClient.EnableSsl = true;
        smtpClient.Port = 25;
        smtpClient.Timeout = 20000;
        smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;
        smtpClient.UseDefaultCredentials = false;
        smtpClient.Host = "smtp.gmail.com";
        smtpClient.Credentials = new System.Net.NetworkCredential
        (from@gmail.com, "password"  );


        System.Net.Mail.MailAddress from = new System.Net.Mail.MailAddress(from@gmail.com,
            from,
            System.Text.Encoding.UTF8);

        System.Net.Mail.MailAddress to = new System.Net.Mail.MailAddress("to@gmail.com");



        MailMessage message = new MailMessage(from, to);
        message.Body = "some text";
        message.BodyEncoding = System.Text.Encoding.UTF8;
        message.Subject = "Subject";
        message.SubjectEncoding = System.Text.Encoding.UTF8;
        message.Bcc.Add(bcc@gmail.com);



        message.Attachments.Add(att);

        try
        {
            smtpClient.Send(message);
        }
        catch (System.Net.Mail.SmtpException ex)
        {
            MessageBox.Show(ex.Message); // The operation has timed out
        }