Hellcore Mailer offers folder encryption facility. Encrypted folder, loaded into text editor, is totally unreadable (contrary to unencrypted folder) and access is possible only by program after entering correct password. Since password alone is not stored anywhere, there's no easy way to recover it.
Program remembers entered passwords so you don't need to re-enter them multiple times across one program session. Remembered passwords will be flushed ("forgotten") upon switching users, closing program, after clicking appropriate command from "Folder" menu, ... or whenever program or Windows crashes or when restarting computer. Encrypted folders are distinguished from others by a small padlock icon and encrypted folders with remembered password - with key icon.
To encrypt folder, select a folder from the tree, then use "Change password" command from "Folder" menu. If folder was already encrypted, you'll need to reenter old password. To decrypt folder, enter empty password and click "OK" (clicking "Cancel" will not change/remove password). Currently there's no password recovery tool for HCM folders so don't lose it!
Note: if you're using an user lock and wish to encrypt one or more folders but don't want to remember another passwords, click here.