Each mail message is stored in a folder. A Pine folder is equivalent to a VMS MAIL folder in a VMS MAIL mail file.
220.127.116.11 Folder Name Case-Sensitivity
While both Pine and VMS MAIL folder names are case sensitive, Pine
users must be much more mindful of this fact. (VMS MAIL automatically
converts folder names to upper case unless you surround the folder name
18.104.22.168 Newly Created Folders and Placeholder Messages
For VMS MAIL files, a new folder is automatically created the first
time a message is saved to it; a folder is automatically deleted when
all messages in the folder are deleted. So when you use the Create
folder command in Pine to create a new folder, the folder will be
created with a placeholder message in it.