We are importing data from CRM to a DE. What I want to do is to send out a welcome email to newly added subscribers on real time. For this I have created a data filter using joindate = today on main DE and a filter activity in an automation which runs on every two hours to check new subscribers in the main DE. so that I can use that filtered DE to send welcome email but the result filtered DE can't seem to be overwritten. It is carrying previous data and then fresh data for present date after every two hours.
Can somebody help me with best practice to send welcome email to subscribers getting added to a DE in real time Via Journey or triggered send.