$ perl mailbox_parser.pl /home/zwon/Mail/FreeBSD-security | head -n 20
00000 => 0000000000 => FreeBSD Security Advisory FreeBSD-SA-04:03.jail
00001 => 0000007411 => [FreeBSD-Announce] FreeBSD Security Advisory FreeBSD-SA-04:04.tcp
00002 => 0000015717 => FreeBSD Security Advisory FreeBSD-SA-04:04.tcp
00003 => 0000024280 => [FreeBSD-Announce] FreeBSD Security Advisory FreeBSD-SA-04:05.openssl
00004 => 0000032992 => FreeBSD Security Advisory FreeBSD-SA-04:05.openssl
00005 => 0000041959 => FreeBSD Security Advisory FreeBSD-SA-04:06.ipv6
00006 => 0000049688 => FreeBSD Security Advisory FreeBSD-SA-04:07.cvs
00007 => 0000058113 => FreeBSD Security Advisory FreeBSD-SA-04:08.heimdal
00008 => 0000069503 => FreeBSD Security Advisory FreeBSD-SA-04:09.kadmind
00009 => 0000077885 => FreeBSD Security Advisory FreeBSD-SA-04:10.cvs
00010 => 0000086754 => FreeBSD Security Advisory FreeBSD-SA-04:11.msync
00011 => 0000094967 => FreeBSD Security Advisory FreeBSD-SA-04:12.jailroute
00012 => 0000102596 => FreeBSD Security Advisory FreeBSD-SA-04:13.linux
00013 => 0000112415 => FreeBSD Security Advisory FreeBSD-SA-04:14.cvs
00014 => 0000123949 => FreeBSD Security Advisory FreeBSD-SA-04:15.syscons
00015 => 0000131204 => FreeBSD Security Advisory FreeBSD-SA-04:16.fetch
00016 => 0000141362 => FreeBSD Security Advisory FreeBSD-SA-04:17.procfs
00017 => 0000151053 => FreeBSD Security Advisory FreeBSD-SA-05:01.telnet
00018 => 0000160935 => FreeBSD Security Advisory FreeBSD-SA-05:02.sendfile
00019 => 0000170195 => FreeBSD Security Advisory FreeBSD-SA-05:03.amd64