In Roundcube you are allowed to create as many folders as you wish. To add a new folder log into your Roundcube webmail client. Then click on the Settings tab in the upper right corner.
Then select the Folders tab and proceed to the ‘Plus’ icon at the bottom:
There you can name the new folder and select a parent folder for it if needed. You can as well select the List view mode. After you fill in these details just click on Save and the new folder will be displayed in your Roundcube.
