Why a milter archiver? If you are required to also log source and destination IPs and BCCs (additional rcpt to's not in a CC field communicated at the SMTP protocol level), then the only option is do this in the MTA, or in a milter application that has hooks in the MTA process (which is exactly why milter was invented). It uses a simple regex file that can be used with several *source target-mailbox rules to define what gets mirrored where. The archiver tries to be as quiet as possible. The possible methods to archive are SMTP, sendmail inject / Postfix inject, IMAP delivery, and milter-add recipient. It was build as a replacement for a Postfix BCC setup: (sender_bcc_maps = regexp:/etc/postfix/archive; recipient_bcc_maps = regexp:/etc/postfix/archive).
PixSteward downloads pictures and metadata from your Flickr accounts and archives them in a relational database on your computer, allowing offline searches and image exporting. With PixSteward, you can safely back up multiple Flickr photostreams with metadata to your Mac, perform sophisticated searches (even where there's no Internet connection), rapidly browse your picture archive and export original-sized JPEGs, PNGs, and GIFs (groups and one-by-one), export sets of pictures along with their metadata for use in other apps, and edit your Flickr tags, titles, and descriptions simultaneously on Flickr and within PixSteward.
iZip provides an easy way to manage .ZIP, .ZIPX, and .RAR archives on Mac systems. When you open an archive with iZip, it appears as a removable disk. This allows management of your files right inside the OS X Finder. All view modes (including cover-flow) just work. For extra security, iZip supports up to 256 bit AES zip encryption.