Are you sure it's setup for POP and not IMAP? IMAP would download any folders that are subscribed but POP only downloads the Inbox. If you logged into the AT&T webmail do your folders there match the ones in your Outlook, same Sent, Inbox, Spam, etc? If so then you are using IMAP.
Can't find a great article for 2003 but it should be somewhat similar to 2010 to unsubscribe from a folder: https://support.office.com/en-us/ar...54fe236aee6a?ui=en-US&rs=en-US&ad=US&fromAR=1
Sometimes in the webmail you can also hide folders from IMAP, not sure if that exists for AT&T's mail.
Can't find a great article for 2003 but it should be somewhat similar to 2010 to unsubscribe from a folder: https://support.office.com/en-us/ar...54fe236aee6a?ui=en-US&rs=en-US&ad=US&fromAR=1
Sometimes in the webmail you can also hide folders from IMAP, not sure if that exists for AT&T's mail.