Previously I was the owner of a Barracuda Spam Firewall and the backlog had helped me many times. It offers a lovely view of all e-mail that has passed the server and even allows for resending those e-mails.
I know e-mail is not supposed to work this way, but it's a great selling point, so users will never lose their e-mail, even when their mailserver would be down and failure notices had to be sent, they could still request a resending of e-mails to their domain.
I am looking for a way to resend all e-mails sent in the last 2 days to a specific domain. Can postfix help with this? Any recommendations in realizing such a construction would be welcome!