No offence to anyone but if its a fresh topic, its better to see him in person instead of email as he will then be able to discuss in greater detail and have more time for us doing so. And we can also ask more qns on the spot. Else if email can ding dong.
To be fair to him, he cannot be replying emails all the time, especially non urgent ones. Else he work till 12 midnight daily also not enough time.
But if urgent or threatening issues, then please email him or call his clinic. These kind of issues, he will usually try to reply fast, that is if he is not in middle of procedure or surgery.