func (m *mailService) SendMail(mail *booking_mail.Mail, config booking_mail_config.Config) error {
	if len(mail.Sender) == 0 {
		sender, err := config.SmtpDefaultSender()
		if err != nil {
			return err
		}
		mail.Sender = sender
	}
	if err := validateMail(mail); err != nil {
		return err
	}
	message := convertMailToMessage(mail)
	mailerConfig, err := convertConfig(config)
	if err != nil {
		return err
	}
	return mailer.New(mailerConfig).Send(message)
}