Postfix - returning emails to sender / demo account

[tahunasky]

Hi,

I have created a theme for squirrelmail so it looks more modern and have made it easier to use for tablet users - larger menu items, message list items etc so can be clicked with a finger.

I want to setup a demo account, so anyone who is interested can see what the modified squirrelmail looks like and try it, and download it if they want.

So i want to be able to stop anyone who logs in using the demo account and who sends an email from that account, to either have the email returned to the demo accounts inbox, or to have the email deleted so it isnt sent from postfix.

I have postfix/dovecot setup with virtual mailboxes, and would use an account something like demo@demo.com...

How can i do this ?

thanks