Hello Nancita1948,
Welcome to Apple Support Communities!
We understand that you are having an issue with deleted emails loading back into the inbox. It's important to have the deleted emails not showing in the inbox. I'll be happy to help with this.
Force close the Mail app and then go to Settings > Accounts & Passwords > Your email account > Your email account again > Advanced. Check the Deleted Mailbox behavior as well as the Move Discarded Messages into. Then restart the iPhone and open the Mail app and delete an email and then test to see if it comes back.
How to force an app to close on your iPhone, iPad, or iPod touch
Restart your iPhone, iPad, or iPod touch
Let us know if you have any questions.
Thank you for using Apple Support Communities.
Take care!