#! /usr/bin/perl
use warnings;
use strict;
use Net::Ping;

my $host = 'irgendeinServer';
my $pingCount = 4;
my $ping = Net::Ping->new('icmp') 
  or die "Error in creating Net::Ping-Object: $!\n";

if (my $count = grep { $ping->ping($host) } 1..$pingCount) {
  print "$count von $pingCount Versuchen erfolgreich";
} # if
else {
  # mail versenden hier, z.B. mit Mail::Sendmail, MIME::Lite, ...
  # ...
}