Howdy Alberto2367,
Thanks for posting in the Apple Support Communities!
We understand you mentioned turning off the setting, but still seeing a suggestion to follow up on emails in the app, right?
We'd first recommend confirming you have iOS 16.0.2 installed on your iPhone to make sure you're on the latest iOS version. If an update is available, be sure to create a backup of your information prior to installing the update. For assistance with either of these steps, check out the following resource: Update your iPhone or iPad - Apple Support
If you're up-to-date, confirm you've turned off the following setting for us. We want to confirm nothing is overlooked, and you can find this info here: Reply to and forward emails in Mail on iPhone - Apple Support
Follow up on emails
If you send a message and don’t receive a response for several days, the email automatically moves back to the top of your inbox to help you remember to follow up.
Go to Settings
> Mail, then turn Follow Up Suggestions on or off.
If you still see the suggestions appear, confirm that you're not in the Follow Up Mailbox for us on your iPhone.
Have a great day!