If you want to go OO you can use Mail::Internet

However, if you're just wanting to put mail into a Mhonarc archive, here's some code I use to do that:

my $mhonarc = "/usr/local/bin/mhonarc"; # Path to Mhonarc executable
my $archive = "/home/httpd/html/archive"; # Path to archive
my $rcfile = "/home/httpd/mhonarc.rc";    # Path to Mhonarc rcfile

my ($m,$y) = (localtime(time))[4,5]; $m++; $y+=1900;

my $month = sprintf("%04d%02d", $y, $m); # make a directory name like 
+YYYYMM
    
unless (-e "$archive/$month") {
    mkdir("$archive/$month", 0775) || 
    die "Couldn't make new archive dir: $!\n";
    }

open(OUT, "|$mhonarc -add -rcfile $rcfile -outdir $archive/$month -qui
+et") ||
    die "Couldn't open mhonarc: $!\n";

while(<STDIN>) {
    print OUT;
    }
close (OUT);
[download]

Make sure the mail daemon has permission to run this script, and that it has permission to create subdirectories in your archive directory.