Pine has a neat (and well-buried!) feature where you can tell it to auto-archive from one folder to another.

I read throug my ISPs IMAP4 interface lots of ways. http://www.mollymail.com is a subscription IMAP4 web
gateway (subscription == no ads!), plus I can read
from my wife's machine as well.

When I finally read a folder on *my* machine, at close time it automatically moves all not-new items to a local folder on my machine and deletes them from the ISP folders.

Also - for those not using IMAP4. Remember that the IMAP separates 'body' from 'attachments', so that you can
quickly read all your email bodies, and then pull down big attachments. You can also pull down small attachments at the end of a mail, skipping over large attachments at the front.

Note that on MacOSX the native/free mailer: Mail.app already stores things in flat text files.
<p>
For the ultimate - look at the Mulberry mailer: http://www.cyrusoft.com/mulberry/ - it is the true power
mailer - almost as good as emacs - without the geekie
command line stuff :-).
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Though my personal favourite is still Pine.

http://slashdot.org/science/02/04/24/1737214.shtml?tid=99

Slashdot has a recent thread on text-mining your email. My only problem with pine is that I have a quota on my Unix account. I'm just about ready to leave groupwise forever, simply because gwise saves your email in an inaccesible, encrypted format.

Imap setup is trival. This allows me to see my mail at work with outlook express, at home with Entourage, and over tty with pine.

Yes I'm running OSX. If anyone needs help with the setup please email me at michael@slavitch.com.

Mail is text. Industrial strength mail handling is best done in text mode.

Some of my largest folders have over 20,000 items in them, and PC-Pine has no problems. PC-Pine conveniently allows mouse use on the text interface, making it essentially painless.

There is a version of Pine for OSX, but I don't know anything about the feature set. I'd still recommend it - I've been using Pine for nearly 10 years now on various platforms. It just doesn't give me grief. It also provides far more flexibility than any other mailer I've seen (does your mailer have Reply Role Rules?).

On occasion it has been known to do a strange thing or two - but because the underlying mails can be viewed and copied with a standard text editor (large files!) even the total loss of Pine wouldn't cut you off from your mail.

There are a whole slew of programs that deal with the mbox
format, which is only so slightly different from plain text. Why
use anything else? I <heart> mailx.