It has happened many times in my organization that some people have left in not really good terms. So when you go to check their computers you find that they normally delete their emails, sometimes you can find them in the deleted folder (lol) but sometimes they even delete them from there.
Here is a way to get them back, I would like to see how other sys admins deal with this...
Download a hex editor from google.
Open the .pst with the hexeditor and delete positions 7 and 13.(just count the letter and do space bar on top of letter at space 7 and letter at space 13.
This will corrupt the pst file. Save it.
Run SCANPST.EXE, normally located in "C:\Program Files\Common Files\System\MSMAPI\1033". It will make a backup and then it will attempt to repair the file. Once its finished, open the .pst on outlook and emails should now be there.
NOW... if you are a sysadmin and you leave the company and you don't want anyone to recover your emails, or at least make it extra harder for them... then all you need to do after deleted your email is go to (in MS Outlook) Tools > Option > Mail Set up > Data Files > Choose the .pst and click on settings > Compact Now.