2 suggestions on this:
currently it's renaming 'sent-mail' folder to 'sent-mail-jul-2006'
would prefer
option1: 'sent-mail-2006-07', would improve sorting even after change of year
option2: 'sent-mail\2006\07', wouldn't be a rename but a create and move of messages though
renaming sent-mail isn't a lucky solution anyway. I mostly use Thunderbird-imap, so I'd have to go to webmail to activate the maintenance. Since I don't always do it on the last of each month, I'd have to manually move back some messages to sent-mail (e.g. going to webmail on 04.aug, makes maintenance 'move' Jul & Aug' mails to sent-mail-Jul-2006)
(however, I gave up searching for the Option to change Maintenance, can anyone point me to the right location?)