#!/usr/bin/perl -w
use strict;
use Data::Dumper;

my@all = qw(bob@foo.com  joe@foo.com jane@foo.com);
            

my %dlists = ( 'listA' =>[ qw (bob@foo.com  jane@foo.com
                              joe@foo.com) ],
               'listB' =>[ qw (bob@foo.com)],
               'listC' =>[ qw (bob@foo.com joe@foo.com 
                               jane@foo.com billy@foo.com)],
             );

foreach my $dlist (keys %dlists)
{
   my ($subset, @extra) = is_array_subset(\@all, \@{$dlists{$dlist}});
   if ($subset)
   {
      print "$dlist contains all users ";
      if (@extra)
      {
             print "and ".@extra." additional addresses\n";
      }
      else
      {
             print "\n";
      }
   }   
}


sub is_array_subset   #returns (yes|no status, @extra)
{
   my ($ref_all, $ref_dlist) = @_;
   
   my %dlist = map{$_ => 0 }@$ref_dlist;
   
   foreach (@$ref_all)
   {
      return (0, ()) if !exists($dlist{$_}); #give up! not subset
      $dlist{$_}++;
   }
   
   my @extra = ();         #is subset, now see if any "extra's"
   foreach  (keys %dlist)
   {
      push @extra, $_ if $dlist{$_} == 0;
   }
   
   return (1, @extra);
}

__END__
prints:
listC contains all users and 1 additional addresses
listA contains all users