You may find Mail::Box::Mbox to be of some assistance as well.

use strict;
use Mail::Box::Mbox;

my $input = Mail::Box::Mbox->new(folder=>$ifile) or die;
for my $msg ($input->messages) {
    print "[$ifile] message subject: ", $msg->subject, " sender: ", $m
+sg->sender, "\n";
}

$input->close;
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