Recovering your deleted E-Mail from Gmail

If you delete any necessary E mail from your Gmail account then there is an option to recover it in your inbox. The option is 'Trash' .Your deleted Email saved in 'Trash' for about 30 days .To recover this you have  to click on  'Trash' > Select the Email you want to recover > Then  click on 'Move to Inbox' .Thus the mail is recovered to your inbox .
Selected item at left side is Trash

In Gmail Trash is situated at left side under the  'compose mail' .