A bit of a strange request, but is there a simple way to have Postfix continually defer mail to a specific recipient, say mail to 'defer.t...@domain.tld' ?
I know with header checks I can do magic like rejecting mail with 5xx errors, but looking through http://www.postfix.org/header_checks.5.html I don't see a 'defer' option, but I'm probably putting the cart in front of the horse with my logic - so I'm open to ideas as I'm clutching at straws a bit.