How do I stop iPhone from fetching emails even when Fetch is off?

On my iPhone 11 with the latest updates I go to Settings, Mail, and Accounts. I have 7 email accounts. At the bottom, "Fetch New Data" is OFF. If I tap that setting, "Push" is off and every account below is set to Manual. Further down under "Fetch", it is set to "Manually". Even if I force close the Mail app, if I leave my phone plugged in and charging overnight, in the morning there are dozens of emails which I then have to manually delete. I prefer to view them on my computer first which removes them from the server and therefore do not go to my phone unless I want them to.

Any suggestions would be appreciated. Thanks in advance.