Just adding that a very similar suggestion has 32 votes. Combined, this
hopefully will get the attention of Shipstation since such a simple
request for shipping software to indicate if a shipment has been
delivered shouldn't take 5 years to develop. ...
Here's a similar request for delivery status through the API:
http://feedback.shipstation.com/forums/330429-product-feedback-fresh-ideas/suggestions/12873405-delivered-flag-in-api
Please upvote it as well if interested in this.
As a new customer to Shipstation, I'm surprised this webhook isn't
available. We've already integrated the "Shipped" webhook but would love
to be able to send customers a "Your package has been delivered" email
through our system as well.