How do I leave the community due to too many emails?

You can't leave the community. But you can manage the emails to receive less.

Also, any email you get is purely of your own doing as only you can set forums, threads, and people to be followed and as such get notified of activity for them.

You can unfollow any forums you follow, you can unfollow any posters you follow, and you can unfollow any specific threads you follow.

You can also limit what. actions trigger emails from your Forum Profile page, by clicking on your user icon at the top right, and then on Preferences then scroll down to the "Messages from Apple" section and uncheck the types of emails you don't want to receive.

As I noted in your other thread, I think you have subscribed to the iPhone forum:

How do I leave this community? - Apple Community

Go here:

iPhone - Apple Community

Click on the "Following" button on the right.