BlueMail displays all IMAP folders from your account exactly as they are organized on your Provider's Server.
If you notice a missing folder in BlueMail that is present on your Provider's Server, it may require enabling for IMAP access.
For guidance on this, see how to enable Gmail's Labels/Folders for IMAP.
Upcoming Feature: We're working on introducing client rules to filter emails based on subject lines, email body content, or sender domains. These rules will help in automatically sorting emails into designated folders, such as user-created folders or the spam folder.