Email is built similarly to your computer's operating system. If you delete any folders, files or shortcuts, they don't disappear forever and end up in a special folder called "Trash". To restore the emails in the email on "Yandex" look "Deleted items" folder located in the left side of the page and open it. Choose the needed to recover the letter and select it by placing a tick in the box next to the sender's address. If necessary, select a few letters.
Click the "Move" button located at the top of the Deleted items folder. Then choose the folder in which you wish to restore the marked letters. Confirm your action by clicking OK.
Go to the settings of the Deleted items folder in your mailbox "Yandex". By default, all deleted emails permanently deleted after each exit from e-mail. To prevent this from happening, and you have the opportunity, if necessary, to recover deleted emails, set the to delete manually.
If you have already removed all email from the Deleted items folder, unfortunately, it will be impossible. In addition, the postal service "Yandex" has a shelf-life of letters in the Deleted items folder, after which they automatically disappear from there.
Ask the destination from which you received a letter, forward you a copy, often sent letters are stored in the appropriate folder in mail so it does not work it will be.
If the sender is not able to send you a copy of the letter, try to contact the technical support e-mail "Yandex". Fill out the appropriate request form with an explanation to your problem. A few days from the administration, you will receive an answer. However, do not expect that the letter will be returned to you necessarily, as every day through the mail online is a few thousand emails and recover your correspondence will be extremely difficult.