80 – 20 Retriever, Isys:Email.Search and Lookout: Searching through Microsoft Outlook and Other Email Clients
Huge email files such as Microsoft Outlook's *.pst are painful to wade through when you need to look for something. Here are some tools that index your email (and desktop) archives and make searching through them almost instantaneous!
If you use Microsoft Outlook or Outlook Express, the *.PST or *.DBX can grow in size quite quickly and become painful to search through. My Outlook archives for instance (since 4 – 5 years now, speak of nostalgia) are now breaking through the gigabyte ranks. Here are some tools that index your email data (and the rest of your desktop actually) and allow you to search through all that bulk nearly instantaneously.
1. isys:email.search
Funky names like Isys:Email.Search aside, this is a pretty light-weight and effective tool for anyone who uses Outlook. I have not tried it with multilingual or double-byte search but I don't see it should not work for all kinds of text on the right kind of OS. The tool remembers your recent searches in a web-browser style interface and the searching itself takes a fraction of a second.
Best feature, after finding results, there's a nifty button to locate the email in Outlook itself. The search results include a handy feature to be sorted by relevance, date, or the number of times keywords appeared in the email. More features from the horse's mouth.
Below is a screenshot of what the Isys:Email.Search interface looks like:

2. (Microsoft) Lookout
Lookout is another popular (probably more popular than Isys) utility that purports to do the same thing. It became so popular that Microsoft recently purchased it. With such a flashy background, I downloaded it with high hopes, only to be terribly disappointed.
After crashing once, and then taking an eternity and a half to index my archives.pst and outlook.pst, it refused to search anything through archives files. The interface is easy enough, and if it works I believe it allows searching through calendar, notes etc (which as far as I know, Isys:Email.Search doesn't allow for now.)
Joel, among many, has some interesting ponderings about Lookout and what Microsoft has in mind (apparently, to leverage the indexing algorithms for MSN!)
3. 80 – 20 Retriever
Save the best for last. The quirkily named 80 – 20 Retriever has to be my find of the year! This no-holds-barred superb all-rounded utility is easily the most flexible desktop indexing software I have seen to date. Visit their website for some screenshots, but here are some of my own.

You can select not only your Outlook archives, but specific bits of your computer as well. Bye bye, Windows Explorer search!

Speaking of flexibility..you can select a bunch of file types, many of which 80 – 20 already recognizes!

Specify how frequently you wish your indexes to be updated

But that's not it, you can update your indexes interactively, as soon as messages arrive!
If you ask me, Microsoft made the wrong acquisition! ![]()
Anyway, YMMV. As for me, I am a happy Isys customer on my office machine, it searches through my email and that's all I need. But at home where my stuff is bursting at the seams, I am a devout 80 – 20 fan.
yor forgot a very important one… LOOKEEN
http://www.lookeen.net
You can call it the follower of Lookout, because Lookout isn´t developed anymore and so isn´t compatible with Outlook 07 and Windows vista!
Lookeen is very fast, reliable and just the best tool to get through your e-mail chaos!!
I use GetMail from http://www.searchterrain.com. It searches Outllook emails very fast. Uncomplicated to use.