This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
I wouldn't think that OS permissions have much to do with renaming a mail directory. Could be, I guess, but a mail server based on file system storage creates, renames and deletes files all the time, so it needs those permissions to function.