How to delete all sms inbox imediately. for that sms contains more than about 4000 how can i delete all.

Surely you don't have 4000 emails loaded for scrolling on the screen? On my HTC EVO mail screen: /menu: /sync,send and receive., I can limit the amount or days of emails recently received being displayed. I can delete them, mark them as junk and all kinds of things. You need to learn how to use the phone email editing features. 95% is junk mail and needs deleting when you get it. You can reset the phone and wipe out all your pictures and phone calls. You can remove the Memory chip and edit it.Those emails are on a server until you delete them there and may show back up. Write down all your mailbox info and password before resetting.
http://www.thefullsignal.com/htc/htc-wildfire/5582/how-hard-reset-htc-wildfire