To manage your folders tap More... | Various Account Settings | Tap your Account | Folder Management | Folder Mapping.
To change the folder mapping, simply tap the folder you wish to map from, and select the folder you wish to map to.
In general, your mapping should match the folders your provider’s web client is using.
This will help ensure that your sync is performed correctly.
Emails that you archive/delete/send in BlueMail will be placed in the parallel named folder for later access on your Web Client and vice versa.
Note: Folder mapping is applied only to IMAP and Exchange and not for POP3.