Squirrelmail LDAP address book filtering

I recently did some hackery to exclude email accounts that aren't "real people" (things like admin mailboxes) from our mailing lists. That was easy enough, just meant modifying the script that pulls entries out of LDAP and pokes them into the mailman's sync_members script. Cool!

Now to do the same with SquirrelMail. Ran squirrelmail_configure... hmm, no option to set up a filter. That's okay, I'm happy to edit config.php... filter, filter... nope, nothing. Hmmm... yet the doco says you can do it, with a config item called, astonishingly, filter. Reading the doco more carefully, oh noes! The filter config item wasn't added till version 1.5.1, and that's a development version. Bugger! Do I want this functionality more than I want to stay on a stable release? Hmmmm...