The folder has children (not yet fully implemented).
This folder contains flagged messages. Some clients call this "starred". Used by RFC 6154.
The last define bit of the flags. The #CamelProvider can use this and upper bits to store its own flags.
The folder does not have children (not yet fully implemented).
The folder cannot have child folders.
The folder cannot contain messages.
The folder is read only.
A folder being shared by the user.
A folder being shared by someone else.
The folder is subscribed.
The folder is a built-in "system" folder. System folders cannot be renamed or deleted.
This folder contains all the messages. Used by RFC 6154.
This folder contains archived messages. Used by RFC 6154.
The folder contains contacts, instead of mail messages.
This folder contains drafts. Used by RFC 6154.
The folder contains calendar events, instead of mail messages.
The folder is an inbox folder.
The folder shows junk messages.
The folder contains memos, instead of mail messages.
The folder is a normal folder.
The folder is an outbox folder.
The folder shows sent messages.
The folder contains tasks, instead of mail messages.
The folder shows deleted messages.
The folder is virtual. Messages cannot be copied or moved to virtual folders since they are only queries of other folders.
The folder is a virtual trash folder. It cannot be copied to, and can only be moved to if in an existing folder.
The folder is write only.
These flags are abstractions. It's up to the CamelProvider to give them suitable interpretations. Use #CAMEL_FOLDER_TYPE_MASK to isolate the folder's type.