Looking for information auto-sender plugin

I would need a plugin that would allow us to send automatically a certain piece of info to one person by email, like this:

1) The user gives his/her email address to a field.
2) The plugin matches the email address to a piece of information in plugin’s database, and sends this information by email to the email address provided. An example would be a user-specific password (not WP but other passwords).

Ideally the plugin would be fast to set up, easy to use and support customizable email templates. Thanks in advance for helping me out here. Cheers, Janne ??