Send an email when there is activity on a NXT / Ardor account address in php? Let say I have a nxt node up on my lamp server and I want to monitor a few NXT / Ardor addresses for activity and then email me. How can this be done? Is there a special setting or a snippet of php code I can use to do something like this? Or do I have to constantly query the NXT server to check if an address has any activity at all? 

I know about https://arguseyes.net/ to monitor transactions, but was wondering how to do it myself.
you can write up a PHP script to grab all the transactions within a set timeframe of the account. Save them in a file.

schedule a cron job to run the PHP every few minute, when it runs, compare the new transactions with the saved one.

If it's new, send an alert email, and update the file.