Question : Build an archiving server

I would like to build an email server whose sole purpose it is to receive a message, log it to a database, and then forward it onto the destination server.

The reason is that i would like to be able to retrieve / re-deliver emails when someone loses them, if the server goes down, or otherwise.

I am thinking this can be done with Postfix and sendmail. Any thoughts?

Answer : Build an archiving server

you will have to write a script that pulls the TO and FROM pieces from the headers and uses that to resubmit, though it will always have new meta data added to the original.

Forwarding will work better if you can forward AS AN ATTACHMENT, because then the headers will remain intact.
Your user can then pull the attachment out of the forwarded item (if they wish) and drop it into a relevant folder.