[Dovecot] Expire plugin - where to start?

[Frank Leonhardt]

I'm running Dovecot 1.1.3 on FreeBSD 7.0 with procmail 3.22 sorting the
output of Spamassassin. Just for me and a few friends.

I didn't like the ageing 'standard' IMAP implementation so I thought I'd
give Dovecot a try and it's really impressive. However, I'm a complete
newbie to its inner workings.

Spamassassin is able to find plenty to chew on so the "Probable spam" mbox
(note) fills up fast. I obviously want to zap the old stuff in there
automatically. It seems to me that the expire plugin is the thing I need BUT
reading the documentation:

http://wiki.dovecot.org/Plugins/Expire

Leaves me to scared to try anything. It's all working and I don't want to
break it or delete anyone's mail. The problem that the wiki isn't accurate
to the version I'm running. For example /usr/libexec/dovecot/expire-tool.sh
doesn't exist. Okay, this isn't Linux, and there's something likely where
I'd expect it on BSD (/usr/local/...) - but it's a binary, not a shell
script. It may be a direct replacement AFAIK, but it may not.

I've been reading the old mailing list about problems with 1.2 and this
reinforces the feeling that the wiki is out-of-sync.

Am I being paranoid? Possibly, but I don't want to be posting a "Help! I've
wrecked my config and deleted all my friend's mail" type message. (Okay, I'd
take a backup first). So could some kind person point me at the latest
documentation?

Thanks, Frank.