Remove duplicates for subscribers on multiple lists in Marketing Cloud Email
|Knowledge Article Number||000213307|
If you have a unique subscriber that is on multiple lists that you're using in a send, Marketing Cloud removes the duplicates on the lists to make sure that the subscriber does not receive duplicate emails.
Marketing Cloud removes duplicate subscribers based on the order that you select the lists. The order in which you select the lists can be important for tracking and analytics.
For example, if you select List A, List B, and List C for a send and there's a unique subscriber on all three lists, Marketing Cloud sends to the subscriber as part of List A, but ignores them on List B and List C. The same is true for the tracking related to that send. If you are looking at tracking broken down by lists, it will count the subscriber's tracking data as part of the List A, but not List B or List C.
If you are using the Guided Send Wizard, the Selected Box at the bottom of the window displays the lists in the order you have selected them. You can use this feature to ensure the lists are being used in the correct order.
If you are using Subscriber Key in your account as the unique identifier, you can have the same email address exist in your subscriber list for multiple unique Subscriber Keys. In this instance, the send would remove duplicates on the Subscriber Key field when that unique value is duplicated.