Hi, Need assistance from here. One of my users trying to delete mail from the personal folder which is only 1GB size. Not over the limited size yet for personal folder. Error message as followed : "The messaging interface has returned an unknown error. If he problem persists, restart Outlook" Client Version : Outlook 2002 10.4712.4219 SP-2 1) Have tried ScanPst, to no avail. 2) Compact Now. Thanks in advanced.. rgds, ken