Right now, trying to create folders with "/" or "." in their name can yield strange results, because Dovecot simply turns every occurrence of the current folder hierarchy separator in a folder name given by the client into a "." (or so it seems). If the folder separator isn't ".", clients can try to create folders with names containing ".", and Dovecot will convert those "." back to the folder separator on listing. It will look like there is an intermediate folder, but Dovecot is unaware of it. If the folder separator isn't "/", clients can try to create folders with names containing "/", which will simply fail.
Judging from to http://www.courier-mta.org/?maildir.html, Courier encodes "." and "/" in the names of the directories the folders are stored as on disk. This means that that of "." and "/" that isn't the folder separator can be used in folder names, but it also means that Dovecot has to be able to perform the recoding. Has any thought been given to this?
-- Magnus Holmgren holmgren@lysator.liu.se (No Cc of list mail needed, thanks)
"Exim is better at being younger, whereas sendmail is better for Scrabble (50 point bonus for clearing your rack)" -- Dave Evans