When you send to a Salesforce Report in Content Builder, the platform creates a temporary DE in the Root DE folder with a retention policy of 5 days named
SalesForce-[guid], for example:
SalesForce-a5ec4b43-9080-4dd4-93b5-a9650c4072b5 (and I thought Salesforce didn't have an uppercase F!).
Anyway, the following fields are created in the Sendable DE with the Subscriber Key relationship of "SubscriberKey relates to Subscribers on Subscriber Key".
So far so good. However, I note that sometimes when I select a Report of Salesforce Contacts (as the target audience in Contact Builder Send Flow), some Contacts are assigned a GUID value for the SubscriberKey, instead of an 18 digit SF Id, as per the example below:
This is problematic as [I assume] that the Subscriber record would be created with the Subscriber Key as this GUID value?! Also, I have some AMPscript code in my email to lookup fields from Contact_Salesforce sychronized DE based on the value of the
_subscriberKey system personalization string.
Does anyone know why this behavior occurs? I'm trying to come up with a logical explanation and can't. These are not brand new Contacts (they have been in Contact_Salesforce DE for a while). I can't figure out why this would happen.