With IMAP you can choose which folders on the email host to copy to Outlook.
With IMAP you can choose which folders on the email host to copy to a local device.
With Outlook you’ll probably want to replicate all folders so you can view anything you need when offline. It also makes backups more comprehensive. But for other IMAP devices like PDA or phones, then you’d probably want to limit the replication so you don’t fill the device.
To change the subscribed folders go to the folder view in Outlook, select your IMAP folder and choose ‘IMAP Folders’
Then click on ‘Query’ to update the folder list from your IMAP host.
Choose which folders you want to appear in the Outlook structure – this dialog box could do with a major improvement by Microsoft’s developers but for the moment we have to work with the clumsy view we’re given.