I don’t know about you, but I’m an email packrat. Steve Gibson, the security genius behind grc.com, recommended mailstore.com and I’ve been really impressed with it so far. It runs locally, sucks in mail basically any source you might have (online mail, local Outlook, Exchange, etc), removes duplicates and then indexes it all for crazy fast searches. I love having everything in this nice clean searchable format across all my various accounts through the years. It’s so much cleaner than my old mess of saved PST files and multiple web mail accounts. This also lets me delete all my old email from GMail and Hotmail. There’s no longer a compelling reason for me to let them see all my old data.
I’m still dusting off some old email archives and finding more lost messages, but right now I have 110,000 messages in this database and it only takes up 3.6GB (and that includes attachments.) Searches return results almost instantly, and if for some reason I don’t want to keep using this program, there are easy options for exporting to a wide variety of locations and formats. The only complaint I have is that it can’t detect duplicates that are loaded from the same source. So if I have a piece of mail that gets loaded from GMail and also from my Outlook cache, it will show up twice.
They have a paid corporate version but there is also a version that is free for personal use. There are probably other solutions out there, but I’m loving this one and I give it two thumbs up!