src/Leevel/Mail/Mail.php
protected function handleDispatch(Swift_Message $message): void
    {
        if ($this->dispatch) {
            $this->dispatch->handle(self::MAIL_EVENT, $message);
        }
    }
protected function handleDispatch(Swift_Message $message): void
    {
        if ($this->dispatch) {
            $this->dispatch->handle(self::MAIL_EVENT, $message);
        }
    }
事件派发.

@param \Swift_Message $message