The setup is ISPConfig 3.1.6 lsb_release -a No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux 8.9 (jessie) Release: 8.9 Codename: jessie The server is in production mode for over one year and working great! some time ago I edited a mailbox and this problem happend. I corrected it and told myself bd problem. But it happend again this mornig and I did some test and it' salways there! After editing any mailbox in the system. The following parameter are empty in `mail_user`table uid = 0 gid = 0 maildir = empty filed ( nothing but not NULL) homedir = empty filed ( nothing but not NULL) And if the user tries to send and received from outlook it doesn't work! In the log here is the error message: Invalid settings in userdb: userdb returned 0 as uid Any idea?