Deleted Mail from GMail

Hello,
I have tried retrieve my deleted email from Gmail and have tried all methods but i am unable to retrieve my deleted email.

As some one said in the forum that email dont get deleted from gmail if that is the fact then i am unable to find my deleted emails.

I have tried to go to the all mail search and without updating any fields have just clicked the search button and the answer was negative for the email which i was searching.