I've been testing a Knack to Zapier to Mailchimp integration where user records when they are either CREATED or UPDATED, will (via Zapier), update a Mailchimp Subscriber. It's all working great for most of the Knack User fields, such as First Name, Last Name, Phone Number, and even some other misc fields that exist in the Knack User object and that I added to my Mailchimp List.
HOWEVER, I've run into an issue where if, in Knack, a user record's EMAIL address is updated, the Zapier to Mailchimp integration is viewing this as a new Subscriber and creating a new Subscriber in Mailchimp, rather than updating the email address of the existing Mailchimp Subscriber.
I'm wondering if anyone else has encountered this issues and whether there is a solution or workaround? It would seem that if I could pass my unique Knack User ID to Mailchimp (POSSIBLE) and then have Zapier/Mailchimp use that field to know whether to either CREATE or UPDATE the Mailchimp Subscriber, this would work. But I don't know if that is possible. I haven't found anything from Googling the topic.