Subscriber Key Email send question

Question

https://help.salesforce.com/articleView?id=sf.mc_es_subscriber_key_scenarios.htm&type=5

"When the birthday email goes out to the Loyalty Birthday List, Lisa and Jill each receive a separate email to their family's shared address."

Basically I was under the impression that if a subscriber key is unique, but share the same email in the all subscribers list - that the email will only send once but it appears in the above article it will be sent multiple times to the SAME ADDRESS with different content.

Doesn't this count as spam and isn't this a risk? So if a family shares the same inbox with the same birthday, all members will receive the same email with different content? Does Marketing Cloud not check if an email already received a send during the sending process? Then cancels the send if it detects that the email ALREADY RECEIVED this email>?

Hope I am making sense and I just wanted clairty - thanks!

Answer 1

This is partially correct. Unless you actively ask for the send process to dedupe on email address, both Subscribers Keys sharing same email will receive each their own version.

You can select the dedupe option upon configuring the send, as described in the help docs. Do observe, that send process picks the recipients randomly, so you can’t be sure which of these two Subscriber Keys receives the single email.