Computer Help and Support

Do you access through a program like Outlook or through a website?
If it is through a program, is it set to POP mail? If so, your computer could be downloading the mail from your server, and the phone wouldn’t see it. iPhones are default set as IMAP, which basically means your phone mirrors what is on the server. But a POP mail downloads and deletes from the server.

My other suggestion would be to delete the account from your phone and add it back. There may be some funky error in the phone settings and that might fix.

I’ve run into weird errors with iPhone mail settings but they are usually easy to fix by deleting and reentering the mail account.