To automate event notifications every 15 minutes in Adobe Campaign Classic and ensure users do not receive duplicate notifications, the following workflow activities are used:

Scheduler Activity:This activity is set up to trigger the workflow every 15 minutes. The Scheduler allows precise timing control over when workflows execute, ensuring the notifications are sent at the desired intervals.

Test Activity After Targeting:The Test activity helps exclude users who have already received a specific notification. Placing it after targeting ensures that only new recipients (those who haven’t received the notification) are selected, effectively preventing duplicates.

This combination ensures that the notifications are automated at regular intervals, with the Test activity filtering out any users who have already received the notification. Using Scheduler and a Test activity after targeting meets the requirement of avoiding duplicate notifications while sending them at the specified intervals.