use Data::Dumper;
$mail='foo@bar.com';
$dn = 'blah';
@members=('bob','carol','ted','alice');
$rec = { DN=>$dn, MAIL=>$mail, MEMBERS=>[@members] };
$hoh{$dn} = $rec;

print Dumper($rec);
print Dumper(\%hoh);

##</code><code>##

$: perl 1149939.pl
$VAR1 = {
          'MAIL' => 'foo@bar.com',
          'DN' => 'blah',
          'MEMBERS' => [
                         'bob',
                         'carol',
                         'ted',
                         'alice'
                       ]
        };
$VAR1 = {
          'blah' => {
                      'MAIL' => 'foo@bar.com',
                      'DN' => 'blah',
                      'MEMBERS' => [
                                     'bob',
                                     'carol',
                                     'ted',
                                     'alice'
                                   ]
                    }
        };
$: