My Thunderbird 2.0 fail me, my Inbox with size of 500MB was gone :sad: . Well blame it on myself for not backup the mailbox, so I decided to use GMail as my Default Email client for my corporate email. With this I can sleep in peace because Google will do my backup :-)
If later I decided not to use GMail as my email client, I can still rely on it to auto Archive all my company email. :cool:
After further investigation, it was cause by Symantec AntiVirus which quarantine my Inbox when a virus was detected. So the blame was not on Thunderbird.