Can forwarding be setup so it sends a copy to main "corporate mail box" and still reach its recipient?
As I understand forwarding, if the email arrives at an existing email
account, a copy will stay at the account
and be sent on to the forwarded address. In other words, a copy is made and sent on. On the other hand, if you do not have an actual email account for an address, but just a forwarder, then only the forwarded copy survives. I think. I haven't played with it too much.
My two concerns are that someone could turn off forwarding (if they know what they're doing) and that some manual labor will have to be done to read in messages at the central copy site. For the former, perhaps there's a setting to prevent ordinary users from changing settings via the webmail interface. Or maybe the forwarding is implemented as a plain text file somewhere, and a cron job could check it every 15 minutes or so to make sure it hasn't been tampered with (check size and last-modified date or something). For the latter, I would assume that someone has written a client that will read arriving mail into some kind of file or database. Maybe a "filter" would do that. At worst, you'd have to get the source to some "open" project (such as Thunderbird) and grab the appropriate code (or tweak it to automatically download emails and then read them from the inbox to a separate file for each account, and run it every 15 minutes via cron or task scheduler). You want the end result on the central site to be that the email ends up in some file, available for searching and printing, and disappears from the server so it doesn't build up.
Instead of forwarding, maybe you could use a filter on each account to copy the email contents to a central server, without (somehow) disturbing the original email. I'd sure love to have a toolkit for handling emails (I've asked for this before -- a framework for filters, autoresponders, spam filters, autoprocessing, forwarders, etc.). Anyway, there's probably a million ways to skin this cat -- start googling! You just want to have some idea of how many users, how much mail, how long of retention period, searchable in what ways, and so on, that will meet whatever corporate and legal requirements get thrown at it.