Destination org feature enablement before deploy
Key Takeaway
A good deployment plan lists the steps the target org needs before and after the deployment, so the deployment doesn't fail or leave features inactive.
A deployment moves changes from a source org into a target org, also called the destination org. The target org often needs its own preparation before and after the deployment. An admin there must allow incoming changes, and some settings must be turned on or handled by hand so components arrive working.
Authorizing orgs and deployment connections
Every deployment has a source org, where changes are built, and a target org, which receives them. Both orgs must be authorized to send and receive changes before anything moves.
For change sets, an admin in the target org must authorize uploads across the deployment connection between the two orgs. Until that happens, the source org can't upload a change set to that target org.
The Deployment Connections list automatically includes the production org and all its sandboxes. Change sets can move between any of those orgs, but no other orgs. If an org has no sandboxes provisioned, the user could see an "Insufficient Privileges" error on the Deployment Connections page.
Authorizing deployment connections and uploading change sets both need information from the production org, so neither works while the production org is undergoing maintenance. During that time, you can build an outbound change set, but you can't upload it.