Question: Where can I find the `PHP` code that sends the e-mail to the user? I want to add the `username` & `e-mail` in my newsletter `database` and I can't find the code that sends the `e-mail` to add my `query` there.

Thank you very much!

Answer: 
Try this plugin [Contact Form DB](http://wordpress.org/extend/plugins/contact-form-7-to-database-extension/)
You can use [PHP mail function](http://php.net/manual/en/function.mail.php).

Point your contact form's action to the `PHP` script, add some validation, send mail or save info to database.