Can someone help clarify use case where we should have Subscriber key related to multiple email addresses?
We generate our own subscriber key but we want to give a Subscriber opportunity to be communicated to different email addresses (what he wants to receive on what email) but we still want to track him through 1 Subscriber key.
How should we approach to this scenario? Possible solutions?
In order to understand the multi-email address scenario per Subscriber Key, it is vital to understand the logic behind email address in a sendable data extension vs. email address in All Subscribers list.
When a send to a data extension occurs, the following process occurs at sendtime, under normal circumstances:
If the value does not exist, a new record is created:
The related Subscriber Key field value is set as Subscriber Key on the All Subscribers list and the value in the field set as an Email Address datatype will be set as Email Address on the All Subscribers list
If the value does exist:
You CAN ask Salesforce to change the settings on the platform, to change this behaviour, allowing you to store and use multiple email addresses for each Subscriber Key, regardless of email address stored in All Subscribers.
When a send to a data extension occurs, the following process occurs at sendtime, if setting on the platform are changed by Salesforce:
If the value does not exist, a new record is created
The related Subscriber Key field value is set as Subscriber Key on the All Subscribers list and the value in the field set as an Email Address datatype will be set as Email Address on the All Subscribers list.
If the value does exist:
From a day-to-day operations, this is the easiest and quickest approach, however it DOES have an impact on tracking.
In summary, regardless of the Email Data Source setting, the Email Address value on the All Subscribers list is not updated at sendtime. If the Email Data Source business rule is enabled, the only difference in behavior is that the Email Address value is overridden at send time.
The tracking architecture is linked to subscribers on a system-generated field called SubscriberID. When pulling any data from tracking that produces an Email Address, the tracking system looks up the Email Address on the All Subscribers list using the SubscriberID field.
If Email Addresses can't be matched, it will result in inaccurate tracking results for any individual subscriber whose Email Address present in a data extension differs from that of the All Subscribers list, based on the same Subscriber Key. This inaccuracy propagates to inaccurate results in the following objects when based on Email Address (but not limited):
A more solid solution would be to update the email address in All Subscribers list prior to sending out the email to that particular Subscriber Key, however it would require substantial business logic to ensure this is done at the right time prior to any send-out: transactional or bulk. This will keep your tracking data consistent.
