make recuva able to recover deleted email

This is not even possible. Emails are on a server. When the email is deleted it is then removed by the server.

If you are using a client like thnderbird to view your email. It is only connecting to the server and then displaying what it finds. When you click delete all it is then doing is sending a http request to delete that email.

If you are not using a web based email client then deleted emails are stored on your computer as .dbx files if you use Outlook Express.

there are plenty of .dbx viewer softwares on the net but most of them cost.

A little bit of info about this here

Treat .dbx files with GREAT care.

http://www.insideoe.com/files/store.htm

Was not thinking about the ones stored on the pc. But this only will work if compact folders has not been touched.

Agreed.