Hi, somehow Exchange messed up the rights on the existing mailboxes because I cannot delete the mailboxes (from active user directory -> Exchange Tasks -> Delete Mailbox) nor can I add additional mailboxes to the already existing ones in M:\Maildomain\MBX. How can I get rid of the existing mailboxes and build up a new mailbox tree? or How can I restore the default rights to the mailbox tree? Thanks in advance for your help, Gerhard