you didn't mention on what is the software used in the e-mail. If it is a regular outlook not outlook express try to search all pst files and then copy that and try to import that pst file when you open the outlook.ON the other hand if outlook express is used .. I think it is hard to recover.
Since you are using win2k there is a big possibility that user profile in the computer. it is in c:\document and setting ...
If you are not connecting to the domain.. remove the computer from domain and make a member of a workgroup then reboot. Then log on locally then join domain and then join the domain. Again make another reboot and then log on as local administrator, then log off and log on as domain administrator, then reboot once again and then log on as the user... I'll bet the user get its profile and those e-mail if you didn't manually deleted the profile but if you deleted them by mistake.. then out of luck to recover that user SID .