My users are complaining about the 5 day limit zimbra uses for determining if a message can be delivered. At least I think it's 5 days, or close to it. Some research on postfix shows this as being the maximal_queue_lifetime variable in the main.cf, something that I thought was regenerated every restart by zimbra. So obviously I can't use that.
The end result that we want, in case I am barking up the wrong tree, is that any email sent out should be returned much quicker so appropriate action can be taken. It doesn't matter if it's ours or their fault really, but we need to know if an email can reach it's destination way before a week is up.