Newsletter module aims to be a full blown newsletter solution for Drupal 7. It is especially recommended for people that need more than one newsletter list for their site.
This module protects users email address, encrypting them into the database. This module doesn't alter user experience.
In case of database hacking, this sensitive data would be useless for the hacker.
It uses the Encrypt module, providing the encryption method. Easy to use :
install the DataBase Email Encryption (dbee) module : the encryption will be enabled for all users email address.
Uninstall it or disable it : it will disable the users email address encryption for all users email address.
The encryption can be enforced by using the Real AES module.