Hi Matan,
Frist of all it’s not really possible (or at the very least bad practice) to mix order data and subscriber data, so adding a tag to the subscriber is not the way to go, as one subscriber can have multiple orders.
So this information needs to be attached to the order.
We do already send in financial_status an fulfillment_status for the orders, that looks like this:
pending, on-hold and processing status is translated to “pending” in Mailchimp, that sends out the order confirmation
completed sets financial_status to “Paid”, that sends the invoice, and it sets fulfillment_status to “fulfilled”, that sends out the shipping confirmation
We also send in cancelled and refunded and here is a code snippet that allows you to send in other custom order statuses:
https://github.com/ibericode/mc4wp-snippets/blob/master/premium/ecommerce/order-financial-status.php
However, what I’m not sure about is the Mailchimp.com side of things… eg if it’s possible to create another email campaign based on another “non standard” financial status or fulfillment status. Do you have a paid account with Mailchimp? If so, maybe you can ask their support if it’s possible to trigger a campaign on a custom financial status or fulfillment status.If so, then we can simply use the code snippet example above to translate your delivered order status into a custom status at Mailchimp and that would be all…
Hope that helps. If you have any questions, please let me know!