#!/bin/sh

find "$1/" -type d -name cur -printf '%h\n' | \
  sed -e "s,^$1/,=,g" -e "s,^$1\$,$2," | \
  egrep -v '^=(sp(ool|am)|discard|retrain(/(sp|h)am)?)$' | \
  sort | xargs echo mailboxes