When i for example use the Roundcube Webmail Client i can see Folders which are not shown in my regular Mail Client programm. How do i see every Folder?
Modern mail clients always offered the possibility to only show subscribed folders and hide the ones which were not subscribed. Nowadays the clients should be configured by default to show every available folder (regardless if subscribed or not). If you have some old configuration, which iterated through many updates, then it could be that you still only see the subscribed ones. Below you find configurations to always show all available folders (regardless of their subscription status).
Edit the Account Settings (e.g. right click on that Account and choose Settings)
Left click on Server Settings.
Push the Advanced Button.
Make sure the Setting Show only subscribed Folder is not set.
- Make sure you have selected at least one folder (e.g. Inbox)
- right-click on the account name in the folder pane.
Select IMAP Folders
Unmark the checkbox show only subscribed folders.
Apple Mail (Snow Leopard)
Apple Mail in Snow Leopard does automatically show every folder. If you just created a new one you have to restart Apple Mail.