You should try to get into the habit of checking the return value of all the method calls and either handle failures or die accordingly.

my $pop = Net::POP3->new('localhost', Timeout => 30) ||
   die "Couldn't connect to localhost\n";

$pop->login($user, $pass) ||
   die "Couldn't login as $user with $pass\n";

# etc...
[download]

This will save you some grief in the long run.

-- vek --