Is email alert system is decommissioned? Nowadays I'm not receiving any email(alerts) when the script is executed

What email alerts are you referring to? I think you should get in touch with your broker for this.

In zerodha, we can set alerts to notify us through email if a script executes/cancelled/rejected for some reason. But this service was not active from few days earlier. I just checked with broker and seems it was disabled for now. So please ignore my query.