email is business secret. i do not want to exposed to my staff or newbie hacker. for some one do not know zencart and php, so this way, i can keep my email secret.

i want to encry customers email address at mysql. and then displace correct email, that is, decode if necessary. i know how to encode,decode. but i do not know where to put those code.

1. when customer register, the code will encode the email and insert mysql.
2. when send email to customer for welcome email and order confirmation email, the code will decode the email and send to correct email address.

where to insert my code to get it work? or any better idea.