I need a solution to send the OLD password of a customer who click and enter his email address in Forgot your password page. The default email template send just a link inviting the customer to reset his password at the site's page.
The current password of a given user cannot be retrieved from the database. Community Edition uses a salted md5 hash and Enterprise a salted sha256 hash. I.e. It's not encrypted, it's an irreversible hash which the users input is hashed and then matched against when logging in to verify validity.
This can be done by resetting the password through the backend
Customers > Manage customers > [choose customer] > Account information > Password management.
It is not possible to send the old password.
Recovering the old password might be userfriendly for your customers, but from a security point of view it's the best if the password can't be calculated back again and a new one will be generated. Just imagine someone retrieves access to your database - he/she could decrypt all passwords of your customers (which, might be used by them on other websites too...).