I have an interesting use case for journey builder and I want to know how MC will react on this use case.

I am running a journey with some contacts and some of the contacts are duplicates have same email address and same SF contact Id's but they belong to different accounts. Now, when I will start the journey, What will happen?

JB will send emails to all the contacts ID even though they are same but belong to different accounts?


It will only send email to one contact with that email address and subscriber key?

NOTE: Contact key is linked with subscriber key in all subscriber.

Please help me with this!

Thanks Adam

  • You need to specify which contact evaluation setting and re-entry mode you are going to set up in the journey
    – Duc Le
    Dec 14, 2023 at 9:21
  • Account relationship plays no role in Journey Builder. It is only looking at the Contact ID/Subscriber Key Dec 14, 2023 at 11:42
  • @DucLe ok, then it will send emails to both the contacts with same subscriber key and email address?
    – Adam Coder
    Dec 15, 2023 at 8:48
  • @LukasLunow Yeah, I know. I just wanted to be clear what will happen if there will two records in DE with same email address and subscriber key. Will JB send email to both records?
    – Adam Coder
    Dec 15, 2023 at 8:50

1 Answer 1


In my experience with Journey Builder, if duplicate emails and subscriber keys exist, only one email is sent.

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