I'm guessing that you've got this code in a loop, and run it once per client. If this is the case, take a look at the below code. It uses an eval block to catch any errors per each client, and if it fails, it will print a notice and per runrig's suggestion, retry two more times before giving up and moving on to the next client.

#!/usr/bin/perl
use warnings;
use strict;

use Net::FTP;

my $user='steve';
my $password='...';
my $file='re.pl';
my @clients = qw(localhost example.com);

for my $client (@clients){

    for (1..3){

        my $ftp;

        eval {
            $ftp=Net::FTP->new(
                      $client, Timeout => 2, Passive => 1
                    ) or die "Could not Connect.\n";
            $ftp->login ($user, $password);
            $ftp->binary;
            $ftp->put($file) or die "Error Uploading.\n";
            print "$client done on attempt $_\n";
            $ftp->quit;

        };
        last if ! $@;
        print "$client broke on attempt $_\n";
    }
}

__END__

$ ./ftp.pl
localhost done on attempt 1
example.com broke on attempt 1
example.com broke on attempt 2
example.com broke on attempt 3
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