How can I fix the Mail app?

We have an iPhone 16 Pro2. The mail app is not working at all and when I delete it and follow instructions to reinstall my email account, the setup does not even have all of the options to enter info that the instructions say. When I enter the host name that mirrors our other (working) phone, it does not have the "mailbox behaviors" in the advanced settings. It does not have the IMAP Path Prefix line, and it does not receive any mail. The folders I had have disappeared. It all is correct on my iPad, just not on the phone.