Find my emails

If mail is going to trash when you receive it, it could be a configuration setting on the server side, or you may have marked them as junk. You may want, after moving mail back to the inbox, remove the account from the phone, then power cycle the phone, then add the account back. See if that clears the issue. It will not lose any of your mail.

Recover them from the Trash. In Trash, select the mail, then move to the Inbox.