I first beg apology for those who are experienced about MT script and mistakenly click this post and found its a simply a beginners script. Sorry bro to bother you.
So let talk about the script. sometimes i need to know which IPs in my networks are alive and which are dead. I am using RB450G v5.7. My following script is combined of couple of scripts, I dont have any credit i just edited some couple of scripts 
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My script is ping a range of ips whatever size you like . i put 1 to 255, ping each ip 5 time if found request time out then it will send a email with the subject ip- ipaddress is down. I am using GMX mail. cause gmx is free and simple no need tls or ssl, allow pop3 and default smtp port. just put mail.gmx.com ip 213.165.64.43 /tool email . so start playing the game…
:for i from=1 to=254 do={
:global ipadd “192.168.11.$i” ;
:if ([/ping $ipadd count=5] =0) do={/tool e-mail send to=routeros@gmx.com subject=“IP-$ipadd is down” }
}
[IF ANYONE KNOW THE EASY WAY LET ME KNOW PLEASE]