How to Stop Showing Duplicate Transactions in Subsequent Alerts

Summary:

Whenever the Alert runs, it picks up all the transactions happened before along with the new one. We want the Alert to work in incremental way so that it picks up the transactions that happened only after the last alert ran.

Content (required):

We have set up an alert to trigger when a certain Action is performed on the employees. We did 5 such transactions and then ran the alert. It processed all the 5 transactions successfully. This is right. However, when we re-ran the Alert, it again picked up those 5 transactions. This is incorrect.

We want the alert to process in incremental way. We want the alert to process the employees who were acted upon only after the last alert ran. However, every time the alert runs, it picks up all the employees.