use strict;
use warnings;
use Net::POP3;
...
if (my $pop3 = Net::POP3->new ($serverName, 'Timeout' => 30))
{
  if (my $numberOfMessages = $pop3->login ($user, $pass))
  {
    if ($numberOfMessages == 0)
    {
      WriteLog ('info', "No new messages");
    }
    else
    {
      WriteLog ('info', "Found " . ($numberOfMessages + 0) . " new object(s)");
      for (my $messageNumber = 1; $messageNumber <= $numberOfMessages; $messageNumber++)
      {
        WriteLog ('debug', "\$messageNumber: $messageNumber");
        my $messageSize = $pop3->list($messageNumber) || print "Error: $!";
      }
    }
  }
}