Determine whether email filed in a specific folder. Then click on the folder name in the left margin. Locate the "search your email" text box at the top-right of the screen. Emails are also in the Deleted option. You can find the email in the deleted option.
You can see Old mail only if you have not deleted it. You can select the pages and check the old mails. If your have many pages just click on the old page number where you can find the old mail. If you have deleted the old mail you will not be able to get that back
We can find the old emails by searching any word or phrase that has been used in that email;in the 'search your email' menu which is on the upper right portion of the page.