I must be blind again, but I can't get it to work (yet) so any suggestion is very welcome. Server: ISPConfig 229, Ubuntu 6.10 fully updated. Squirrelmail per ISPConfig package. Maildir and IMAP. Client: Thunderbird 126.96.36.199 All works, mail is arriving at the Inbox. Now I want to create a subdirectory to sort my emails. With Squirrelmail, no problem, I can just create a directory. With Thunderbird, the newly created directory is a subdirectory of "Inbox", whereas in Squirrelmail it's a subdirectory of the root.. When I try to create a directory with Thunderbird, no juice. No error, no message, just no creation of the directory. No erors in my log-files. Only if I specify to create a subdirectory of Inbox, the requested directory is created. According to Google (well, the references I found) this is due to the NAMESPACE setting. But the default is "INBOX." in my Thunderbird. As it should be for Courrier to fix this problem and have directories directly under "root". Any suggestions?