Hello, christophe52.
I understand that you would like to stop incoming work email from coming through once you are done for the day. I’m a true believer in establishing a healthy work-life balance, and I’m glad to help.
The iPhone has a couple of features that can help you manage this. Do Not Disturb won't stop the emails from coming in, but you can use it to stop notifications. You can easily set it up on a schedule so that you do not need to worry about it from one day to the next.
Use Do Not Disturb on your iPhone, iPad, and iPod touch
You can also tailor your notification settings to help reduce interruptions, but you would need to adjust this regularly.
Use notifications on your iPhone, iPad, and iPod touch
I feel that the Do Not Disturb feature will deliver on your request. I hope you find this information helpful.
Best Regards.