Laravel.io
public function toMail($notifiable)
    {
        return (new MailMessage)
            ->subject('New Post Available')
            ->greeting('Hello, Subscriber')
            ->line('There is a new post. We hope you will like it.')
            ->line('Post Title : '.$this->post->title)
            ->action('View Post', url('post/{{$post->slug}}'))
            ->line('Thank you for using our application!');
    }

Please note that all pasted data is publicly available.