my $max_tries = 5;
my $tries = 0;

# login() returns false, if unsuccessful
while( ! $ftp->login('anonymous', 'me@myself.com' ) {
  $tries++;
  die "We tried $tries times, but cannot connect!\n" if $max_tries == $tries;
  warn "Attempt $tries: Could not connect, trying again.\n";
}

print "Yay! We logged in!\n";